The Jasco Motion Dimmer is an ideal Z-Wave product for home automation. We want the lights to come on automatically when we enter a room and off again when everyone has left. The motion sensing needs to be reliable and sensitive and ideally not involve changing batteries every few months. Thus, a wall mounted, always-on dimmer with a built-in motion sensor fits our needs perfectly. In this blog article I’ll explain a few tricks to getting the most out of this handy device.
Configuration Parameters
The Jasco Motion Dimmer has 18 configuration parameters. The parameters can be set by reading the documentation and then programming them using complex combinations of button presses. But, with a Z-Wave device, it’s much easier to program them via Z-Wave. Most Hubs allow you to program the configuration parameters though the process to do so is different with every Hub. The parameters are briefly described on the Jasco web site ezzwave and on the Z-Wave Alliance web site. However, these brief descriptions don’t clearly describe what the parameter does and more importantly, what the best settings are to get the most out of this device.
Several parameters are two bytes instead of just one even though the value will typically fit in one (the value is 0-255). The parameters listed with a (2) in the Name field below means they are two bytes. If there is no (2) in the name then just send one byte. Sending just one byte to the 2 byte parameters can confuse the dimmer and it may not set the parameter to the desired value. The result is frustration as you sent it your desired value but it didn’t take it or set it to what appears to be some random value. Always send the proper number of bytes for each specific parameter. Some Hubs will handle this for you, but others must be done manually.
The table below is the list of all parameters with the less important ones greyed out and my own more detailed description of what each parameter does.
#
Name
Default
Description
1
Timeout
5
Motion Sensor Timeout 0=5s test mode 1-254=minutes 255=disable Time the lights remain on in Occupancy mode
2
Assoc dim
255
0=99 dim level 255=last ON level Dim level to send to associated lights. The Hub is better at controlling other lights so ignore this parameter.
3
Mode
3
1=Manual – Motion sensor does not control the local load 2=Vacancy – only turns lights off 3=Occupancy – Lights on when motion detected and off when none after Timeout
4
Invert buttons
0
0=normal (top=up, bottom=down) 1=invert (top=down, bottom=up) If you accidentally install the dimmer upside down, inverting it will correct your mistake
6
Motion Enable
1
0=disable 1=enable Why would you disable motion sensing?
7
Steps via Z-Wave
1
Leave at 1 See the Ramp Rate discussion below
8
Speed via Z-Wave (2)
3
Number of seconds for the dimmer to go from 0 to 100% via a Z-Wave command
9
Steps via button
1
Leave at 1
10
Speed via button (2)
3
Number of seconds for the dimmer to go from 0 to 100% via a button press or the motion sensor
11
Steps via AllOnOff
1
AllOnOff commands are obsolete
12
Speed via AllOnOff (2)
3
Leave at default
13
Motion Sensitivity
2
1=high – detects people at a distance 2=Medium 3=low – less likely to detect a pet
14
Light Sensing
0
0=disabled 1=enabled If enabled and the room is brightly lit the lights will not turn on when motion is detected
15
Reset Time (2)
2
0=disabled 1=10s, 2=20s, 3=30s, 4=45s, 5-255=n*15s When Motion is detected a notification is sent to the hub saying there is motion. After Reset Time, a reset notification to clear the motion event is sent. If you are still in the room, motion and reset notifications will continue to be sent. Depending on your hub you may want to change this but generally the default works.
16
Switch Mode
0
0=disabled 1=enabled Switch mode changes the dimmer to act like a switch so the light turns on (100%) or off instantly. If you want this mode, buy the cheaper switch instead.
17
Switch Level
0
0-99=Brightness level Sets the dim level when motion is detected or the top button is tapped. You can press and hold the top which will continue to increase the dim level further if you have set this to something other than 99. Ignored when Switch Mode is enabled.
18
Dim Up rate
0
0=fast 1=slow This applies only to commands sent via Z-Wave and only applies to the dim up ramp rate. Best to leave this at the default of 0 and use parameters 8 and 10 instead.
19
Exclusion Mode
0
0=any button 1=Tap X then ON will enter exclusion mode, Tap X then tap OFF 10 times in less than 5 seconds will factory reset the dimmer. X is the little button behind the face plate to the left of the ON button. Enable this mode if there are other Z-Wave networks nearby (IE: in a condo or apartment) to reduce the risk that one of these other networks will exclude the dimmer when you tap one of the buttons. When 0, every time you tap either On or Off the NIF is sent. If a nearby controller is in exclusion mode, your dimmer will be excluded from YOUR network and it will seem to stop working. I recommend setting this to 1 either way to reduce the chance even within your own household of accidentally excluding the dimmer.
Configuration Parameters
Dimming Ramp Rates
When a dimmer changes the light level from 0 to 100%, the time it takes for the light to go from 0 to 100% is set by the Ramp Rate. The dimmer has six parameters related to the dimming ramp rate, parameters 7 through 12. The ramp rate is configured using a pair of parameters for three different methods of changing the light level. The “Steps or Levels” is the number of dim levels that the light level changes every Time Step. Always leave the Steps at the default of one. Anything more than one results in the light level “jumping” from one step to the next while dimming. This jumping is just plain unpleasant so always leave Steps at one. The Time Step parameter (Speed) is how often the Step is added to the current dim level in 10 millisecond increments or every 1/100th of a second. Since the dim level goes from 0 to 100 and it takes 1/100th of a second to increment once, then the Time Step simply is the number of seconds for the dim level to go from 0 to 100%. The default ramp rate is three seconds which is what most people expect and in general is a good value.
The three pairs of ramp rates provide different ramp rates based on the method to turn the light on or off.
Z-Wave command – parameters 7 and 8
Button or Motion detection – parameters 9 and 10
All On/Off commands – parameters 11 and 12
The easy ones to ignore are the All On/Off parameters as the Z-Wave All On/Off commands are obsolete. Simply leave these at the default. The remaining two pairs can be used for different purposes based on what is changing the light level. I recommend leaving the Button/Motion parameters at the default of 3 seconds. This is the expected ramp rate of the average dimmer. When a person presses the button or motion is detected, they expect the dimmer to react at about this speed. Setting it to less than 3 seconds results in the user being unable to set a mid-level as the ramp rate is too fast to accurately stop at a mid level. The dimmer pretty much becomes a switch. Setting the ramp rate to more than 3 seconds will quickly become annoying as it just takes too long to get to the desired level. That leaves the Z-Wave command ramp rate parameters. These can definitely be programmed to be longer, potentially much longer so that the level changes quite slowly and an occupant can override the slowly changing light level by pressing the button or waving their hands in the air so the motion sensor will detect them.
The Z-Wave Multilevel Switch command Version 2 includes a Duration field which is the number of seconds to go from 0 to 100% or the ramp rate. If the Hub sends a dim level command with the Duration field, the configuration parameters are ignored and instead the ramp rate is set to the Duration value in the command. Some Hubs let you assign the Duration field but most only support Version 1 which only has the level and no duration which the dimmer will then use the configuration parameters dim rate.
Association Groups
Three association groups are supported with up to five NodeIDs each. Your Hub should automatically assign itself to Group 1 which is the Lifeline group. The Lifeline group is required for every Z-Wave Plus device and identifies the NodeID where any state changes will be sent. The dimmer sends your Hub commands whenever the sensor detects motion or the state of the local load changes (someone presses the On or Off button). Thus, it is very important that the Hub be assigned to Association Group 1 so Hub app on your phone matches the actual state of the dimmer.
Groups 2 and 3 are identical and simply send Basic On/Off commands to the associated NodeID. Assigning a NodeID to these groups will send a command to turn the NodeID either On or Off when motion is detected or not. Assigning a NodeID to these groups enables the motion detector or the buttons to turn on/off other lights in a larger room quickly. Using the association groups is fast since the dimmer sends the Z-Wave commands directly to the light and works even if the Hub is offline for some reason.
Multi-channel associations are supported but generally you want to avoid them. Multi-channel adds another layer of encapsulation to every frame which just slows everything down. The only time you might want to use multi-channel association is if you wanted to control a specific outlet in a power strip with the motion sensor. Multichannel would be required to choose which of the outlets in the power strip to turn on/off. However, I recommend that you let your Hub do complex operations like this and keep things simple with the dimmer.
Group
Name
Description
1
Lifeline
Motion Sensor readings and status of the load are reported
2
Basic On/Off
BASIC SET On or Off commands
3
Basic On/Off
BASIC SET On or Off commands
Association Groups
When a NodeID is assigned to an association group, the node will be interviewed and depending on the command classes the node supports, the dimmer will send different commands. Specifically, if the device supports CRC16 then the commands will be encapsulated in CRC16 which improves the reliability of the command being delivered without errors but isn’t really necessary.
Why are there two association groups you ask? The reason is to match the feature set of many other Jasco Z-Wave products which send different commands in the two groups. But for this device it always sends the same commands from either group. My recommendation is to not use Group 3 at all. If you want to associate other lights directly with the dimmer, use Group 2.
Recommendations
There are many ways to use a motion sensor wall dimmer. Perhaps the toughest question is where to install it? The first place I installed my motion dimmers are in hallways. When your arms are full of groceries, you want the lights to just come on when you enter. More important in my household is that the lights go OFF shortly after everyone has left the hallway! Back in the bad ol’ days, the hallway lights were always on all the time because no one ever turned them off! The challenge with hallways is typically they are 2, 3 or more way lights so the placement of the motion sensor is key. Jasco makes an inexpensive Add-On Switch that connects to the Traveler wire to enable the multi-way switch so it can be operated manually as before. However, getting the motion sensor to cover a long thin hallway can be difficult since the motion sensor is built into the wall and cannot be pointed down the hallway. In that case you may need to use a separate battery powered motion sensor to trigger normal dimmer switches. What this means is that a wall mounted fixed position motion sensor may not work for all situations but the sensor has a wide angle lens so it will work most of the time.
Easy Mode – Use the Defaults
The simplest configuration is to use the dimmer as-is using the default settings. The defaults work as you would expect and obviously is the easiest to setup and use! Perhaps the only real decision here is which wall switch to replace. In this mode the lights come on when motion is detected and off after 10 minutes. Perhaps the one configuration to adjust would be the Timeout especially for hallways. Since you’re usually passing thru the hallway and thus moving quite a bit, the Timeout can be short, one or two minutes. A short Timeout keeps the power consumption to a minimum while providing sufficient light to travel thru the space.
Slow Dim – Parameter 8
The next parameter to consider customizing is the Z-Wave dim ramp rate (Parameter 8). The motion sensor and the buttons continue to use the typical 3 second ramp rates which are what people would normally expect. But when a Z-Wave command sends a command to change the light level, a significantly slower ramp level can be used. This configuration lets the user override the dim level either by moving or pressing a button. The slow ramp can be 30 seconds in this mode or perhaps as short as 10s. This always gives the person in the room time to override the slow dim but still provide enough light to move around the room as needed. The most common case for this is in a room where people might be reading, watching TV or working on a computer where they are not moving very much.
Manual Mode – Parameter 3
Configuration Parameter 3 has three different settings. The default is Occupancy mode which is the most useful and common mode. Vacancy mode only turns the light off but you have to manually turn it on – don’t bother with this mode. The third option is Manual mode which disconnects the motion sensor from the local load. Your Hub has to then turn the light on when the motion sensor detects motion. The time from motion detection to the light coming on has just a little more delay but often this delay isn’t that much. What you gain from this setup is a great deal more flexibility in how the lights should dim up or down.
My Setup
The first motion dimmer I installed was in my mudroom which is pretty much a hallway with a closet but it is an L shape. It is a 3-way switch with wall switches at each of the 3 entrances. Fortunately the switch with the incoming power is the one with the best view down both legs of the L and is where I mounted the motion dimmer. I use Easy Mode in this situation since the desired operation is quite simple. You walk in, the lights come on, you leave and 10 minutes later the lights go off. I suppose I should shorten the Timeout but I’ve never been in the mudroom and had to waive my hands to turn them back on even when rummaging thru the closet where the motion sensor can’t really see me. If I made the timeout shorter, then the lights might go off before I’ve found what I’m looking for. Nothing craters the WAF Factor more than the lights turning off before my wife has found what she’s looking for in the closet!
The next one I installed is in the garage. In this case I used a Motion Switch rather than a Dimmer since its a few bucks cheaper and I don’t need a dimmer in the garage. Easy Mode is fine in this situation. I have a 2 car garage about 24′ square and the motion sensor is able to detect motion of a person just about anywhere in the room even though the wall switch is in the corner next to the door into the mudroom. I did change Motion Sensitivity (Parameter 13) to high to get the entire garage to detect motion. I also enabled Light Sensing (Parameter 14) as my garage has quite a few windows and has plenty of light during the day. There is no way to adjust the level of light to disable the light from turning on but it seems to work when I want it to and doesn’t turn on the lights when the room is sufficiently bright from natural sunlight.
My master bedroom closet seemed like a simple setup but took a little more tweaking. What I want is the light to come on at a low level (say 5%) but if it’s daytime or early evening I want the light to come on fully. With this setup the light is just enough to find my robe in the middle of the night without waking my wife but she can choose an outfit in full illumination. Since the dimmer has no idea what time of day it is, I need to enlist the help of my hub. I set the Switch Level (Parameter 17) to 5% and the Z-Wave Dim Rate (Parameter 8) to 30 seconds. Then I created an event on my hub (Homeseer) that sends an ON command whenever motion is detected and the time is between sunrise and 9pm. This ON command will take 30s to come on fully which is nice. Since the Button Dim rate remains at 3s the buttons operate as normal so if my wife is impatient she can press the top button to quickly get the lights fully on.
My kitchen is the most complicated setup by far. First of all, I have an eat-in kitchen which is pretty wide and the dimmer often doesn’t detect if we are sitting at the table which is at the end of the kitchen. The Jasco Motion sensor is mounted basically in the middle of my kitchen and there are a variety of kitchen appliances on the counter blocking the view of the kitchen table. To cover this wide space I enlist a second motion sensor that is close to the table so even if someone is sitting there quietly, perhaps reading, the combination of the two sensors ensures that the lights only go off when no one is there (most of the time). I use Manual Mode (Parameter 3) in this case and rely on my Hub to combine the 2 sensors readings and control the lights appropriately. Manual Mode effectively disconnects the Jasco Motion Sensor from the Dimmer. When either motion sensor detects motion, I set the dimmer to full on. When BOTH motion sensors have not detected motion for about 20 minutes, then I turn the dimmer off. By relying on the smarts of my Hub I can do even more interesting events where the timeout is different late at night when someone is probably just passing thru and I can use a lower dimmer level. At meal times I push the dimmer fully on as we’re probably preparing food so the more light the better. I could even check for the light level provided by the windows in the room and then only add as much illumination as needed though I haven’t experimented with this yet.
Conclusion
Once you have a few lights automated, you’ll almost never touch the buttons. The lights come on when you walk in and off when everyone leaves. Your family quickly becomes used to it and it blends into the woodwork which is the way things should work. Adding motion sensor lights to your home is an incremental upgrade. I suggest starting with your most-used light such as a hallway or mudroom. Once the family has adjusted to one, you can add more in other locations as the budget allows.
The Jasco Motion Dimmer is a versatile and invaluable home automation device. Never needs batteries and is configurable enough to handle even fairly complicated situations. The trick is to use the right tool for the job. The dimmer is fine for basic operation but use the smarts built into your Hub to do more complicated tasks. Being highly configurable unfortunately results in more complexity but I hope my guide helps you make the most of this device. Let me know what you think and any other Z-Wave related topics you’d like to discuss in the comments below.
Frequently Listening Routing Slaves (FLiRS) are a class of Z-Wave devices that are battery powered but wake up every second to check if there is a message waiting for them. FLiRS were initially used for door locks. Door locks have fairly large batteries since they have to move a mechanical device to lock or unlock a door. Typically this is four AA batteries. With this fairly large battery storage, we still need a method to talk to the lock but can’t stay awake all the time as the batteries would only last a week or so. FLiRS to the rescue! FLiRS lets the lock remain asleep 99% of the time and wake up very briefly once per second and listen for an always-on device to be sending a “Wakeup-Beam”. The Beam is a constant transmission of the NodeID and a 1 byte hash of the HomeID telling that specific node to fully wake up and be ready to receive a message. This low-power mode allows Z-Wave devices to run for years on a battery but still be ready to lock or unlock within 1 second.
Z-Wave door locks first appeared in 2008 but since then FLiRS mode has found uses in other battery powered devices. The next most popular FLiRS device are thermostats. Older heating systems which rely on a simple mercury switch have only 2 wires and do not need power. To upgrade these simple switches to a smarthome Z-Wave thermostat means a battery powered device has to last for years on a single set of 3 or 4 AA batteries. FLiRS to the rescue again! Since a user is fine if it takes a few seconds to change thermostat settings, FLiRS is the ideal way to extend battery life and still be connected to the internet.
Recently we’ve had a number of window shades come to market based on FLiRS. Window shades have the challenge that often there is no power near the window so they need to be battery powered. Sometimes a solar cell can help keep the batteries fresh but the FLiRS mode is key to long battery life. Controlling the shades with Alexa is the favorite mode to show off your smarthome – “Alexa, set shades to 0%”. The challenge comes in if you want a battery powered wall switch or some other device to directly control the shades. This is usually done using a Z-Wave Association where the wall switch is “associated” with the shade and then controls the shades without the Hub being involved. This is faster and in some cases can be done without a Hub at all. The trick is getting the wall switch to send the Beam to wake up the shades. Setting the Association is insufficient. A Return Route has to be sent which will tell the wall switch to send a beam.
Association
The first step in directly controlling the shades from a wall switch is to assign the shade to an Association Group. Using the PC Controller application to add the association is done by selecting the destination in the left window and then choosing the Association Group to add it to in the right window. In this case I’ve added the shade NodeID=3 to the Wall Controller NodeID=4 Group 2 which will send a BASIC_SET when I press button 0.
Note the checkbox for Assign Return Routes. Initially I’ll leave this unchecked. This is what many Hubs fail to do properly – set the Return Route anytime an association is made. So what happens when I press Button 0?
The Wall Controller (nodeID=4) sends the Basic Set command 3 times but the Shade (nodeID=3) does not ACK. The Wall Controller tries two more time with Explorer Frames trying enlist anyone else in the network to deliver the frame. But they all fail. Why? Because the Shade is asleep waiting for a Wakeup Beam.
Assign Return Route
To get the Wall Controller to send a FLiRS Wakeup Beam we have to tell it to send one! That is done by assigning a Return Route. In the PC Controller the easy way to do that is to simply check the box in the Association window. The way a Hub should do it is with the SerialAPI command ZW_AssignReturnRoute( SourceNodeID, DestNodeID, callback) which is SerialAPI command 0x46 (see section 4.4.4 of INS13954). We can do this manually in the PC Controller using the Setup Route window shown here. The key is to select the Return Route radio button, then in the left pane select the Wall Controller (the Source NodeID) and in the right pane select the Shade (the Destination), then click on Assign.
When you click on assign you’ll see 4 frames sent from the Hub to the Wall Controller which includes the information to send a FLiRS Beam to the Shade.
These Assign Return Route frames are not officially documented but you can pretty quickly figure out the details of the data. Once the Return Route frames have been delivered to the Wall Controller, it will then send a Wakeup Beam to the Shade before sending the Basic Set.
Here we can see the Shade ACKing the Basic Set in line 72 so the Wakeup Beam did its job and woke up the shade so it was ready to receive the basic set and close the shade.
Z-Wave Long Range Impact
Z-Wave Long Range supports FLiRS types of devices but it doesn’t support Associations. Z-Wave Long Range is a star network so all communication has to go thru the hub. Then the hub forwards the message on to the FLiRS device after Beaming to wake it up. There is no way for a Long Range end device to send a frame to another end device, it has to go thru the controller.
Door Locks are critical to the security of the home and thus communication must be reliable and fast. This document brings together the many issues unique to door locks and guides the developer toward the most robust and interoperable implementation. These are mostly recommendations, not requirements and do not guarantee Z-Wave certification. Z-Wave allows for plenty of product differentiation, but it is important that common lock functions operate in the most interoperable fashion.
Z-Wave door locks entered the market in 2008. The problem was that at the time the Z-Wave Command Classes were missing standardized reporting of status of the lock and user codes. Initially Alarm CC was used by the locks to send various notifications to the hub to deliver status updates. The problem with this method is that each manufacturer used a unique set of commands to deliver the different status updates. Shortly after these initial locks hit the market and with the arrival of the Z-Wave Alliance, the Z-Wave specifications were updated and now locks can send standardized messages to deliver status changes. The standardized messages make Hub software much easier as basic operations can be received without the need for specialized code for each lock manufacturer.
Z-Wave Command Classes for Door Locks
SDS14224 Z-Wave Plus v2 Device Type Specification section 4.5.1 (in Version 10) specifies the Mandatory and Recommended Command Classes (CC) for Lock Device Types. Some command classes have a minimum version required for certification. However, the developer is free to choose the command class version that meets the product needs. As command classes have matured, commands have been added which in turn adds complexity and more code space. Every command in a command class must be implemented by the lock based on the version supported. If you don’t want to support some commands in a later version, then only declare the earlier versions in the Version CC.
Mandatory Command Classes
Door Lock CC (V4 or later)
Battery (V1) – unless the lock is mains powered
Basic CC – 00=UNLOCK, FF=LOCK (does not appear in NIF)
Security S0 CC – for backwards compatibility to older gateways that don’t support S2
S0 may change to recommended in the future but is mandatory in 2020
Common Mandatory CC for All Z-Wave Plus v2 Devices
Association, version 2
Association Group Information
Device Reset Locally
Firmware Update Meta Data, version 5
Indicator, version 3
Manufacturer Specific
Multi-Channel Association, version 3
Powerlevel
Security 2
Supervision – See discussion below – you SHOULD be using Supervision!
Transport Service, version 2
Version, version 2
Z-Wave Plus Info, version 2
Most of these command classes are handled by the SDK and/or the Z-Wave Application Framework (ZAF). There are some customizations to many of these command classes, but the effort is minimal.
Recommended Command Classes
User Code CC – If the lock has a keypad this CC is used to program/enable the codes
Notification CC – Send various lock status messages to the Lifeline NodeID (Gateway/Hub)
Time CC – See the section below on the time/clock command classes
Clock CC
Time Parameters CC
Generic Schedule CC – Defines time/date ranges to enable/disable User Codes
Schedule CC – Simpler but less flexible schedules using any Z-Wave command
Authentication CC – use with RFID, NFC, Mag cards etc. and link ScheduleIDs with User Codes
Other Command Classes
Door Lock Logging CC
Door lock logging CC provides a means to retrieve an audit trail of operations
Typical use: If the hub is offline, a log of all operations is recorded and can then be sent when the hub comes back online
Barrier Operator CC – Typically used with motorized entry gates which are like locks
Entry Control CC -Used with RFID or other means that have ASCII strings
Relies on the Hub to authenticate the string and then send an unlock command
Typically used for Keypads which do not control a lock
Use Authentication CC for locks
Configuration CC (V3) – configure specific features that are not supported by other CCs
See the Door Lock Configuration SET command which should provide most of the needed configuration
Configuration CC should only be used if really necessary as it is less interoperable
Application Status – Can be used to reply back to the Hub that the lock is currently busy and cannot execute the command just received
Use Supervision instead
Protection CC – enables a Child Protection mode
AntiTheft CC (v3) – Locks the device so if stolen it is a brick
Multi-channel – Multichannel should not be necessary
Multi-command – Can be used to return several commands in a single frame to reduce battery consumption however with the smaller payload size in S2 it is not recommended
Obsolete Command Classes – do not use these
Schedule Entry Lock CC – use Generic Schedule CC instead
Alarm CC – Use Notification CC (V3 or later)
Security Levels
Security S2 has three security levels and S0 has one for a total of four different security levels:
Security S2 Access Control – Strongest Security level only used with devices that provide access to secure areas – door locks
Security S2 Authenticated – SmartStart requires a QR code/DSK – lights/thermostats/sensors
Security S2 UnAuthenticated – used by a small number of early S2 devices – generally not recommended – Does not require QR Code/DSK
Security S0 – Legacy security mode – slower, uses more battery power, less secure than S2
The Security S2 Unauthenticated and S2 Authenticated keys are NOT recommended due to potential security holes. S2 is rapidly becoming commonplace so it is expected that S0 will no longer be mandatory but will change to recommended. S0 is slower, uses more battery power and is less secure than S2 due to the network key being exchanged using a known encryption key. Security S2 uses Diffie-Hellman elliptic curves to exchange the keys, an out-of-band DSK is required to join the network and Nonces are pre-computed enabling a single frame compared to three for S0 (Nonce Get, Nonce Report, Encrypted frame). Locks are required to use the Security S2 Access Control level.
Recommended Security Levels:
S2 Access Control
S0 if supported or if legacy support is desired (mandatory in 2020)
Reporting State Changes
All Z-Wave Plus devices are required to send to the Lifeline NodeID (typically the Hub) when their state changes. The Z-Wave Application Framework True-State Engine (TSE) can be used to send state changes. The primary state changes in a lock are:
Currently most locks rely on the Hub to install/remove User Codes and to manage the times and dates when the codes are valid. Thus, the lock need not know the current date/time and does not need to store schedules and apply them to User Codes. This makes the lock firmware simple and keeps the complexity of schedules with the Hub and its significantly greater processing, storage and user interface capabilities. However, many rental property agencies prefer the battery powered lock to have the schedules built-in so that even if there is an extended power or internet failure, the proper User Codes are enabled/disabled at the proper times. Thus, there is a desire to have these schedules managed within the lock itself. Fortunately, Z-Wave already has the command classes in place to support them, but schedules are complicated.
Generic Schedule CC – Recommended
Generic Schedule CC can set Time Ranges and then Schedules which are comprised of one or more Time Ranges. A Time Range has Start and Stop Date/Time fields and each field can be enabled or ignored. For example, a Time Range can be every Monday from 1pm to 3pm (date and minute fields are ignored) or can include specific dates like 2022 May 24th from 11:23am to 4:57pm. This makes the Time Range very flexible and able to specify virtually any type of date/time combination.
A Schedule is a list of Time Ranges that are either Included or Excluded to build the schedule. Thus, a Time Range of M-F 8am-5pm could be included but then 1 Jan 2022 from 4pm to 5pm could be excluded. In this example, the Schedule includes the first Time Range and Excludes the second. Generic Schedule only creates the ScheduleIDs. It does not hold any commands or perform actions. Authentication CC is then used to link a Schedule to a User Code or other authentication method. There are up to 64K Schedule and Time Ranges though each device reports the number supported in the Generic Schedule Capabilities Report. Due to the memory required for schedules and time ranges most devices will typically only have perhaps a dozen or so of each.
Schedule CC
Schedule CC is different than Generic Schedule in that Z-Wave commands are used instead of ScheduleIDs/AuthenticationIDs/UserCodes. Schedule CC is usable for any Z-Wave command and not just those that use the Schedule IDs. Schedule CC is most often used with thermostats or other devices that change state automatically based on the time/date. While Schedule CC can be used to execute User Code Set commands to enable/disable User Codes on a schedule, it is less flexible than Generic Schedule CC. For simple weekly schedules this CC will work OK but trying to build more complex schedules quickly becomes cumbersome.
Schedule Entry Lock CC
The Schedule Entry Lock CC has been deprecated and thus should not be used in new locks. Use the Generic Schedule CC instead. There are less than a dozen certified locks with Schedule Entry Lock CC. Hubs may want to control this CC to support specific locks but it is not required.
Authentication CC
Authentication CC is used to connect a User Code to a Generic Schedule. Authentication CC can also be used in conjunction with RFID, NFC, mag stripes, BLE or other forms of user authentication. It is then used to enable/disable various access methods based on a schedule. Thus, Authentication is flexible but with that flexibility comes complexity.
Time CC vs. Clock CC vs. Time Parameters CC
If a lock supports schedules to enable/disable user codes, then it needs some way to determine the date and time. For example, the cleaners code only works on Tuesdays from 2 to 4pm. How is a lock supposed to get the current local time and date so it knows when to enable the cleaners code?
There are three different command classes for getting various parts of the time/date. Time Command Class is mandatory for all Gateways and is the most full featured method. Unfortunately, not all gateways support it yet, so most devices need to support one of the others for use with older hubs. Clock CC is defined in SDS13781 – Z-Wave Application CC but the other two are defined in SDS13782.
Time CC
Clock CC
Time Parameters CC
Second
V1(Local)
V1 (UTC)
Minute
V1(Local)
V1
V1 (UTC)
Hour
V1(Local)
V1
V1 (UTC)
Day of Week
V1
Day of Month
V1(Local)
V1 (UTC)
Month
V1(Local)
V1 (UTC)
Year
V1(Local)
V1 (UTC)
Time Zone Offset Hour, Minute
V2
DST Offset
V2
DST Start Month, Day Hour
V2
DST End Month, Day Hour
V2
Command Classes for setting the Date and Time
Time CC – Recommended
Time command class is described in SDS13782 (Z-Wave Management Command Class Specification). Time CC is mandatory for all Z-Wave Plus Gateways and thus is the recommended method for a lock to set its clock to the current local date and time. Time CC Version 2 adds time zones and daylight savings time support if desired however V1 provides the necessary functionality in most cases.
The Z-Wave specification recommends having an association group to identify the time server node however the Gateway is expected to have an accurate time reference so using the Lifeline is acceptable.
The Time CC does NOT have a date/time SET command. Thus, the hub cannot set the date/time and instead should wait for the lock to GET it. The hub can send a Time/Date REPORT to the lock when a lock is included in a network. However, the lock must send a Time GET command within the first few minutes to accurately set its internal clock. The lock should then periodically send a Time GET to ensure the internal clock remains accurate to the local time. Only the lock knows the accuracy of its real-time clock. Thus, the lock will determine how often it needs to update its internal clock and send a Time GET when needed. The hub should not send Time Reports unless responding to a Time GET other than immediately after inclusion. Note that for certification purposes a door lock CONTROLs Time CC, it does not SUPPORT it. The Hub is required to SUPPORT Time CC.
Time Parameters CC – Optional
The Time Parameters command can SET/GET/REPORT the year, month, day, hour, minute & second of the UTC time. However, it does not set the time zone which must be done via the Time CC V2. Thus, Time Parameters CC relies on the hub to send the current UTC time but the lock can also send a GET and adjust its internal clock to match the one from the hub. However, this requires support on the hub software which is not mandatory so not all hubs will be able to provide the current date/time.
Clock CC – NOT Recommended
Clock command class is sent by a Hub and can set the local weekday and time. Thus, it only supports a 7-day schedule since it cannot set the date, just the day of the week. Typically, the Hub would send a Clock Set as part of inclusion in the network. Since the clock on the lock will drift, the lock must periodically send a Clock Get to the Hub and to maintain time accurately. This method is NOT recommended. However, on some old hubs this is the only method available.
Recommended Time Setting Algorithm
The algorithm below provides a basic guide for setting the time. The first step is to wait for the inclusion and the security negotiation to complete. Then send a Time GET and start a 30 second timer. If a Time REPORT arrives before the end of the 30 second timer, then the Hub supports Time CC so use that. If the Hub instead sends either a Clock REPORT or a Time Parameters SET then that will set the initial time for the lock. The lock will have to continue to send periodic Clock GET commands to the Hub to maintain clock accuracy. If there is no response from the Hub, then the lock has no choice but to disable the schedule features as they require accurate local time.
Depending on the accuracy of the local clock circuitry, the functioning time setting command class should be used to update the local clock at a sufficient rate to match the desired settings. Typically, this would be once per day assuming a 100ppm or better 32Khz crystal is used for the clock (see section Real Time Clock (RTC) 32KHz Crystal below).
Notification CC
Notification CC was originally called Alarm CC which was deprecated at V2 and replaced with Notification CC. When the first Z-Wave locks were developed there was no standardized method for informing the Hub when a lock state changed. Each lock manufacturer was free to choose an Alarm Type and Alarm Level to communicate various status changes. Unfortunately, this resulted in non-standard and non-interoperable Z-Wave commands. Notification CC V3 defined a set of Access Control notification types and events which are described in SDS13713 which is a spreadsheet listing all standard notification types/events. For new lock developments it is recommended to use the standardized commands described here instead of the old Alarm CC ones (V8 or later is recommended). The Alarm CC can still be sent if the lock is joined using Security S0 for backwards compatibility, but their use is not recommended if the lock is joined using Security S2. Alternatively, a Configuration Parameter could be used to enable/disable the Alarm CC commands. Sending these old commands wastes battery power and clogs up the Z-Wave network.
Notification CC is typically used to communicate specific state changes beyond Door Lock or User Code CCs. There is overlap between some notifications and some Door Lock commands. The recommendation is to use Door Lock CC and only use Notification for cases that don’t have overlap. A few examples are shown in the Sample Communication section below.
Supervision CC
Supervision CC is mandatory for all S2 devices. Since locks provide property security and users have very high expectations for reliability and robustness of lock operation, it is strongly recommended that all communication to/from a lock be wrapped in Supervision CC. Supervision eliminates the need to send a Notification that a user code has been SET as the Supervision Report confirms that the command was received, decrypted and executed. See Appendix A for a sample implementation of Supervision CC for the door lock firmware.
The example below shows a lock being unlocked manually by the user. The lock needs to be 100% certain it informs the Hub that the door is now unlocked. To do that, the DoorLock_Operation Report is encapsulated with a Supervision GET command. The first attempt is blocked by RF noise but the protocol will automatically retry sending the frame up to five different routes using the mesh network because the ACK was not received. The second try delivers a frame to the Hub but due to more RF noise, the Hub is unable to decrypt the message. The Hub has already ACKed the frame so the protocol has retired the frame from the transmit queue and will not try again. However, the SDK has started a 500ms timer expecting a Supervision Report within that time. Since the Hub could not decrypt the message, it has discarded the frame. Once the 500ms timeout has expired, the lock will resend the frame. This time it gets thru and the Hub is able to decrypt the message and replies with a Supervision REPORT with a status of Success. At that point, the lock is 100% certain the frame has been delivered, decrypted and executed. The use of Supervision command class ensures delivery and execution of any Z-Wave command and should be used with any critical function of any device.
Door Lock Command Class
Most of Door Lock CC is straightforward and documented in SDS13781. The Lock Timeout vs. Auto-Relock function however needs a little extra explanation. The Door Lock Operation Set (V1) command includes the Mode which assigns either Timeout mode or Constant mode. The Door Lock Configuration Set (V1) command sets the timeout in Minutes + Seconds and whether the lock is by default in Constant or Timeout mode. Later versions of Door Lock CC enable sending a Timeout or an Auto-Relock time in the Operation Set command. Auto-Relock is in force ONLY if the lock is in Constant mode. If the lock is in Timeout mode then the normal Timeout Minutes/Seconds is used and the Auto-Relock values are ignored. Given the more common support of the Timeout Mode, it is recommended to use this mode for improved interoperability. Note that some locks have the timeout or mode as a configuration parameter. While it is acceptable to have these modes read/writeable via Configuration CC, the same values must also be reflected in the Door Lock Configuration commands.
Sample Communication
This section describes the communication between a lock and a hub in various scenarios. All communication is Security S2 encrypted which is shown in most of the examples. The recommendation is to encapsulate all frames in Supervision to ensure the frames was delivered and decrypted.
User Manually Locks/Unlocks
When the user manually locks or unlocks the lock by turning the bolt/lever, the lock must send to the Lifeline NodeID(s) (the Hub) the following:
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
Properties1
Supervision SessionID incremented with each new GET
4
0x09
Len
Supervision Length
5
0x62
CmdClass
Door Lock Operation CC V4
6
0x03
Cmd
Door Lock Operation Report
7
LockMode
00=unsecured, FF=secured – See SDS13781 table 44
8
Properties1
In/out Handles Mode – table 45
9
DoorCondition
Door/bolt/latch state – table 46
10
0xFE
TimeoutMin
Lock returns to secured after these many minutes
11
0xFE
TimeoutSec
Lock returns to secured after these many seconds
12
TargetMode
Target Mode if in transition or LockMode
13
0x00
Duration
Seconds to reach target mode – 0=already at target
Note that Supervision CC is used to ensure the Hub has received and decrypted the frame.
A Notification CC can be sent if the lock was included using Security S0 for backwards compatibility. It is not recommended if the lock is using Security S2 which relies on the Supervision CC to ensure delivery.
Byte #
Value
Name
Description
1
0x71
CmdClass
Notification CC
2
0x05
Cmd
Notification REPORT
3
0x00
V1AlarmType
V1Alarm can be non-zero IF documented in the user manual
4
0x00
V1AlarmLevel
These are used for backwards compatibility
5
0x00
Reserved
6
0xFF
Status
00=notifications are disabled, FF=enabled
7
0x06
Type
06=Access Control
8
Event
01=Manual Lock, 02=Manual Unlock
9
0x00
Properties1
Parameters Length
User Enters a Good User Code
A User Code of “1234” has been set in a deadbolt lock with a keypad at UserID=03. The lock is locked and then the user enters 1234 to unlock the lock.
A Notification CC is sent informing the Hub which User Code was used.
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x13
Properties1
Supervision SessionID incremented since this is a new frame
4
0x09
Len
Supervision Length
5
0x71
CmdClass
Notification CC
6
0x05
Cmd
Notification REPORT
7
0x00
V1AlarmType
V1Alarm can be non-zero IF documented in the user manual
8
0x00
V1AlarmLevel
These are used for backwards compatibility
9
0x00
Reserved
10
0xFF
Status
00=notifications are disabled, FF=enabled
11
0x06
Type
06=Access Control
12
0x06
Event
05=keypad Lock, 06=keypad Unlock
13
0x63
Param
User Code CC
14
0x03
Param
User Code CC cmd = REPORT
15
0x03
Param
UserID=0x03
16
0x01
Param
UserID Status = occupied & enabled
17
0x31
Param
User Code = ASCII “1”
18
0x32
Param
User Code = ASCII “2”
19
0x33
Param
User Code = ASCII “3”
20
0x34
Param
User Code = ASCII “4”
Optionally a Door Lock Operation could be sent to inform the Hub that the door is now unlocked.
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x12
Properties1
Supervision SessionID=0x12
4
0x09
Len
Supervision Length
5
0x62
CmdClass
Door Lock Operation CC V4
6
0x03
Cmd
Door Lock Operation Report
7
0x00
LockMode
00=unsecured, FF=secured – See SDS13781 table 44
8
0x00
Properties1
In/out Handles Mode – table 45
9
0x00
DoorCondition
Door/bolt/latch state – table 46
10
0xFE
TimeoutMin
Lock returns to secured after these many minutes
11
0xFE
TimeoutSec
Lock returns to secured after these many seconds
12
0x00
TargetMode
Target Mode if in transition or LockMode
13
0x00
Duration
Seconds to reach target mode
User Enters a Bad User Code
Currently nothing is sent when the user enters a bad code. There have been discussions that the lock should send the bad code so that the Hub could collect statistics on how many times a user has tried to enter a code and what the code was. This would require a new Notification Access Control Event. Let us know what you think of this idea or get involved with the Z-Wave Alliance Standards Development Organization and make a proposal.
Hub Sends Lock/Unlock Command
A hub sends a Lock or Unlock command. Most locks take a few seconds to slide a bolt and this sequence shows the use of a Supervision Report with a WORKING status followed by a SUCCESS.
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x95
Properties1
Supervision SessionID=0x15 with Status Updates
4
0x03
Len
Supervision Length
5
0x62
CmdClass
Door Lock Operation CC V4
6
0x01
Cmd
Door Lock Operation SET
7
0xFF
LockMode
00=unsecured, FF=secured
The lock immediately responds with a Supervision WORKING report with the More Status Updates bit set indicating another report will come within the next 7 seconds. The WORKING status means the lock is busy moving the bolt and it will take a few seconds to know for sure if it is properly engaged. If the Status Updates bit was 0, then only this supervision report would be sent. If the lock (or more typically a gate) takes more than 10 seconds to reach the final state it is suggested to send a WORKING report every 5-10s. Each time the Duration field should be updated with the estimated time to completion.
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x02
Cmd
Supervision REPORT
3
0x95
Properties1
Supervision SessionID=0x15 – More Status Updates set
4
0x01
Status
WORKING – Once the bolt has finished moving another report will be sent
5
0x07
Duration
Next report will be in 7 seconds or less. The duration should be a worst-case number to handle the case when the lock is jammed.
When the lock has completed the operation, it sends another Supervision Report this time with the Status Updates bit cleared and a status of SUCCESS (if the Status Updates bit was set in the Supervision GET). This frame should be sent as soon as the lock has completed the operation.
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x15
Properties1
Supervision SessionID=0x15
4
0xFF
Status
SUCCESS
5
0
Duration
Target mode completed
At this point the Hub is assured the lock has completed the operation because Supervision CC confirms the command was executed. However, most Hubs want to receive a status update so either a Notification CC, Access Control and Event of 0x03 (lock) or 0x04 (unlock) could be sent. It is recommended to send a Door Lock Operation Report wrapped in a Supervision Get as shown here.
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x0A
Properties1
Supervision SessionID=0x0A
4
0x09
Len
Supervision Length
5
0x62
CmdClass
Door Lock Operation CC V4
6
0x03
Cmd
Door Lock Operation REPORT
7
0xFF
LockMode
00=unsecured, FF=secured
8
0x00
HandlesMode
In/out Handles Mode
9
0x00
DoorCondition
Door/bolt/latch state
10
0xFE
TimeoutMin
Lock returns to secured after these many minutes
11
0xFE
TimeoutSec
Lock returns to secured after these many seconds
12
0xFF
TargetMode
Target Mode if in transition or LockMode
13
0x00
Duration
Seconds to reach target mode
Hub Sends User Code Set
Supervision encapsulated User Code SET enabling the User Code of “1234” for User ID 5.
ASCII ‘4’ – total length of the code is 4 to 10 digits
The lock would then send the Supervision CC REPORT with a value of SUCCESS if the User Code was properly executed otherwise it would return FAIL. If the UserID is more than 255, the Extended User Code Set command would be used. This command can also set multiple codes in a single frame.
When a Hub sends a User Code SET, the Hub typically wants confirmation that the code was in fact properly set. While this isn’t necessary if Supervision is used, it is good practice as that is the only method that a pre-S2 lock can confirm that the User Code was set. Since the Supervision Report already confirmed the User Code has been set, it is not necessary to wrap this frame in Supervision as it is merely informational. If the lock is using Security S0, the notification report confirming the User Code is recommended.
Byte #
Value
Name
Description
1
0x71
CmdClass
Notification CC
2
0x05
Cmd
Notification REPORT
3
0x00
V1AlarmType
V1Alarm can be non-zero IF documented in the user manual
4
0x00
V1AlarmLevel
These are used for backwards compatibility
5
0x00
Reserved
6
0xFF
Status
00=notifications are disabled, FF=enabled
7
0x06
Type
06=Access Control
8
0x0E
Event
0E=New User Code added
9
0x00
Properties1
Parameters Length = none
Hub Sends a Duplicate User Code
If a Hub sends another User Code SET with a different UserID but with the same UserCode, the lock must return a Notification CC Type=Access Control (0x06) with an Event=New User Code Not Added (0x0F). This Notification should be sent encapsulated in Supervision CC if the lock is using S2.
Lock Sends Low Battery Warning
Most locks use simple alkaline batteries so version 1 of the battery command class is sufficient. Use the later versions for rechargeable or complex battery situations.
Battery powered locks should automatically send the Hub the battery level whenever the battery level changes by a significant amount. The lock should send an update if the battery level has changed by more than about 5% from the last report. The amount of change required to trigger an update is up to you, but it should be large enough to only send a battery update every several days or even weeks. Note that changes in temperature can cause the battery level to rise so the trigger should require the level to be lower. Be aware that most Hubs will occasionally poll the battery level which is why sending an update is not needed unless the level has changed significantly from the last report. Zero percent battery level should still allow the lock to operate reliably, but just barely. One Hundred percent battery level should be achievable with a wide range of batteries.
When the Critical Battery Level has been reached the lock must send a Low Battery warning (0xFF). Each lock will have a different Critical Level but it is typically in the 5% to 20% range. When the Critical level is reached for the first time, a low battery warning must be sent to the Lifeline. This warning must ONLY be sent once. Typically, a RAM variable holds a flag that is set when the low battery warning is sent and is only cleared upon power-on reset when the batteries are replaced. The Low Battery warning should be sent wrapped in Supervision command class to ensure the Hub received it. Normal battery reports do not need to be wrapped in Supervision.
Battery Report – Low Battery Warning
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x01
Properties1
Supervision SessionID=0x01
4
0x03
Len
Supervision Length
5
0x63
CmdClass
Battery CC
6
0x03
Cmd
Battery Report
7
0xFF
Level
0xFF=Low Battery Warning, 0-100 otherwise
Lock Updates Local Time
If a lock has schedules that enable User Codes at certain days/times, it needs to know the current local time. See the discussion above about the different command classes that can be used and the hardware considerations later in this document for the necessary hardware to support time keeping. Typically, a lock will send this frame once per day to sync to the local time. Note that in this case Supervision is not used as the clock update is not important enough to warrant the extra overhead and battery power. The frame below should be sent within the first five minutes after inclusion if the Hub does not automatically set the time. Note that the time can be off by a few seconds due to system wide delays.
Lock sends the Hub a Time GET
Byte #
Value
Name
Description
1
0x8A
CmdClass
Time CC
2
0x01
Cmd
Time GET
The Hub responds with Time REPORT that sets the local time to be 5:6:7 (6 minutes and 7 seconds after 5am)
Byte #
Value
Name
Description
1
0x8A
CmdClass
Time CC
2
0x02
Cmd
Time Report
3
0x05
Hour
Local Hour
4
0x06
Minute
Local Minute
5
0x07
Second
Local Second
Lock sends the Hub a Date GET
Byte #
Value
Name
Description
1
0x8A
CmdClass
Time CC
2
0x03
Cmd
Date GET
The Hub responds with Date REPORT that sets the local date to be 10 September 2019
Byte #
Value
Name
Description
1
0x8A
CmdClass
Time CC
2
0x04
Cmd
Date Report
3
0x07
Year1
Local year MSB
4
0xE3
Year2
Local year LSB – 0x7E3=2019
5
0x09
Month
Local Month – 0x09=September
6
0x0A
Day
Local Day – 0x0A=10th day
The lock must calculate the day of the week based on the current date. The Time Offset Get command in V2 could also be used to get the daylight savings date/time if desired. Checking the local time/date at around 3:10am each day should keep the lock accurate to the current local daylight savings time.
Generic Schedule to Enable a User Code
The following sequence assigns User Code 0x05 to be enabled M-F 8am-5pm except on 5 June 2019 from 1:23pm to 6:45pm. First step is to SET two Time Ranges (01 and 02). The Hub should first send a Generic Schedule Capabilities Get to determine how many Time Ranges and Schedules the lock supports.
Time Range Monday thru Friday 8am to 5pm
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x09
Properties1
Supervision SessionID=0x09
4
0x15
Len
Supervision Length
5
0xA3
CmdClass
Generic Schedule
6
0x03
Cmd
Generic Schedule Time Range Set
7
0x00
TRngID1
8
0x01
TRngID2
Time Range ID=0x0001
9
0xBE
Weekday
Weekday Mask = M-F
10
0x00
StartYear1
Note the InUse bit (MSB) is zero for all fields that are not used
11
0x00
StartYear2
Start Year not used
12
0x00
StopYear1
13
0x00
StopYear2
Stop Year not used
14
0x00
StartMon
Start Month
15
0x00
StopMon
Stop Month
16
0x00
StartDay
Start Day
17
0x00
StopDay
Stop Day
18
0x00
StartHour
Start Hour
19
0x00
StopHour
Stop Hour
18
0x00
StartMin
Start Minute
19
0x00
StopMin
Stop Minute
20
0x88
DayStartHr
Daily Start Hour = 8am
21
0x91
DayStopHr
Daily Stop Hour = 17:00=5pm
22
0x00
DayStartMin
Daily Start Minute
23
0x00
DayStopMin
Daily Stop Minute
Time Range 5 June 2019 from 1:23pm to 6:45pm:
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x0A
Properties1
Supervision SessionID=0x0A
4
0x15
Len
Supervision Length
5
0xA3
CmdClass
Generic Schedule
6
0x03
Cmd
Generic Schedule Time Range Set
7
0x00
TRngID1
8
0x02
TRngID2
Time Range ID=0x0002
9
0x00
Weekday
Weekday Mask not used
10
0x87
StartYear1
11
0xE3
StartYear2
Start Year = 2019
12
0x87
StopYear1
13
0xE3
StopYear2
Stop Year = 2019
14
0x86
StartMon
Start Month = June
15
0x86
StopMon
Stop Month = June
16
0x85
StartDay
Start Day = 5th
17
0x85
StopDay
Stop Day = 5th
18
0x8E
StartHour
Start Hour = 1pm
19
0x92
StopHour
Stop Hour = 6pm
20
0x97
StartMin
Start Minute = 23 minutes after the hour
21
0xAD
StopMin
Stop Minute = 45 min after the hour
22
0x00
DayStartHr
Daily Start Hour
23
0x00
DayStopHr
Daily Stop Hour
24
0x00
DayStartMin
Daily Start Minute
25
0x00
DayStopMin
Daily Stop Minute
Now that the two Time Ranges have been defined, the next step is to link them to each other to create a ScheduleID. In this case Time Range 0001 is being INCLUDED and Time Range 0002 is being EXCLUDED to make the desired schedule.
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x0B
Properties1
Supervision SessionID=0x0B
4
0x09
Len
Supervision Length
5
0xA3
CmdClass
Generic Schedule
6
0x06
Cmd
Generic Schedule Schedule Set
7
0x00
SchedID1
8
0x01
SchedID2
Schedule ID = 0001
9
0x02
NumIDs
Number of Time Range IDs = 2
10
0x80
TimeRngID1
11
0x01
TimeRngID2
Include Time Range 0001
12
0x00
TimeRngID1
13
0x02
TimeRngID2
Exclude Time Range 0002
Finally, the Authentication CC is used to link the Schedule ID to the User Code CC UserID
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x0C
Properties1
Supervision SessionID=0x0C
4
0x0A
Len
Supervision Length
5
0xA1
CmdClass
Authentication CC
6
0x06
Cmd
Authentication Technologies Combination Set
7
0x00
AuthID1
8
0x05
AuthID2
Schedule ID = 0005 – can be any value but matching with the UserID is easier to match them up
9
0x01
FallBack
Fallback Status = 01 = enable access based on the schedule
10
0x00
UserID1
11
0x05
UserID2
User Code CC UserID=0005
12
0x00
SchedID1
13
0x01
SchedID2
Generic Schedule CC ScheduleID=0001
14
0x00
NumAuthID
Only the User Code is enabled
In all cases Supervision should be used to confirm the schedule and time ranges are set properly. Alternatively, a GET should be used if the lock is only using security S0. If NFC, BLE or some other authentication technology is used then the NumAuthID would be more than zero to include these other forms of authentication.
Lock Has a Hardware Failure
If a lock has some sort of a hardware failure, there are several Notification Events that can be sent. The most common is the lock is jammed where the bolt is neither in the locked or unlocked position but somewhere in between. Other options are to send a Home Security – Tamper event when the battery cover is removed. The Impact Detected event could be used if an accelerometer detects the lock being smashed. If someone is jamming the RF in an attempt to bypass the lock, then an RF Jamming message could be sent. In this case the lock should store the RF jamming message if the message is not acknowledged by the Hub due to the jamming. The lock should continue to attempt delivery at ever larger timeouts between retries.
Byte #
Value
Name
Description
1
0x6C
CmdClass
Supervision CC
2
0x01
Cmd
Supervision GET
3
0x01
Properties1
Supervision SessionID=0x01
4
0x08
Len
Supervision Length
5
0x71
CmdClass
Notification CC
6
0x05
Cmd
Notification Report
7
0x00
V1AlarmType
V1Alarm can be non-zero IF documented in the user manual
8
0x00
V1AlarmLevel
These are used for backwards compatibility
9
0x00
Reserved
10
0xFF
Status
00=notifications are disabled, FF=enabled
11
0x06
Type
06=Access Control
12
0x0B
Event
0B=Lock Jammed
The lock should also send a Door Lock Operation Report with a value of 0xFE (Door Mode Unknown) if the bolt is not in either the Locked or Unlocked mode.
Z-Wave Long Range
Z-Wave Long Range (ZWLR) support is recommended for locks. Z-Wave Long Range is a star topology with very long range. ZWLR is ideal for a battery backed up hub to talk directly to a distant lock even if the power is out and the Z-Wave mesh repeaters are offline. ZWLR will be available at the end of 2020 and is a software upgrade that can be OTAed to existing units. RF regulatory testing (FCC) may need to be redone to ensure ZWLR meets the applicable regulatory limits.
Hardware Considerations
The 700 series Z-Wave hardware is typically a FLiRS (Frequently Listening Routing Slave) device. Typical power consumption in this mode is on the order of 10uA average with brief peaks of 12mA during a transmit. Once every second the chip briefly wakes up and listens for a Wakeup Beam from the hub or an adjacent node. If the hub wants to talk to the lock it sends the Beam which wakes up the lock and then the two can communicate. Once the communication is complete the lock will again enter a low-power state. The 250ms FLiRS mode can be used to reduce the latency of waking the lock with a tradeoff of additional power draw.
Most locks need to accurately measure time and keep schedules of when to enable User Codes. The 700 series has an internal low power Low Frequency RC Oscillator (LFRCO=32KHz). However, the oscillator is not accurate enough to keep the schedule accurate without frequent updates from the Time Server (LFRCO can drift by more than 1min/hour). Thus, it is recommended to use a 32KHz crystal connected to the LFXO of the EFR32. A low cost 100ppm 32KHz crystal can provide accuracy of 9s per day. Note that if your lock does not support Time CC then an external crystal is not needed.
Use a 32KHz crystal for the LFXO if schedules are supported
One MCU or Multiple?
The Z-Wave 700 series is an ARM processor with built-in cryptography accelerators and plenty of low power peripherals. The ZGM130S has plenty of GPIOs and can be easily extended using simple GPIO expanders via I2C or SPI. In most cases the ZGM130S is more than powerful enough to run the entire lock using the single processor. This avoids the complexity and security issues involved with using multiple microcontrollers within the lock. If a multi-MCU solution is chosen, the communication method between the ZGM130 and the lock MCU should be a UART, SPI or I2C and should be encrypted. Do NOT use the SerialAPI on the ZGM130! The SerialAPI is intended for use with Internet Gateway processors with large amounts of FLASH/RAM/CPU. The SerialAPI does NOT provide support for security encryption/decryption which is built-in to the embedded SDK. The recommendation is to develop your own encrypted serial protocol between processors.
Appendix A: Supervision Encapsulation End Device Example
Z-Wave SDK 7.14 does not have direct support for encapsulating frames with Supervision CC. However, it is easy to add manually. The example below simply wraps the DoorLockOperationReport with the SuperVisionGet IF the device was added as S2 which means the Hub support Supervision CC. The frame is not encapsulated if responding to a GET from the Hub.
Door locks, thermostats and other Z-Wave devices often need to know at least the time and day of the week. In many cases they need to know the full date and time to enable a lock User Code when a renters code is valid or set the thermostat into energy save mode. These devices need a way to determine the current date and time to within a few seconds of accuracy.
Z-Wave provides three different command classes (CC) for getting various parts of the date/time. Time Command Class is mandatory for all Gateways. Unfortunately, not all gateways support it yet, so most devices need to support one of the other command classes for use with older hubs. The question then is how is a device supposed to get the current date/time so the schedule can operate properly?
Time CC – Recommended
Time command class is described in SDS13782 (Z-Wave Management Command Class Specification). Time CC is mandatory for all Z-Wave Plus Gateways and thus is the recommended method for a device to set its clock to the current local date and time. Time CC Version 2 adds time zones and daylight savings time support if desired however V1 provides the necessary data in most cases.
The Z-Wave specification recommends having an association group to identify the time server node however the Gateway is expected to have an accurate time reference so using the Lifeline is acceptable.
The Time CC does NOT have a date/time SET command. Thus, the hub cannot set the date/time and instead must wait for the device to GET it. When a device is included in a network, it must send a Time GET command within the first few minutes to accurately set its internal clock. The device should then periodically send a Time GET to ensure the internal clock remains accurate to the local time. Note that for certification purposes a device CONTROLs Time CC, it does not SUPPORT it. The Hub is required to SUPPORT Time CC.
Time Parameters CC – Optional
The Time Parameters command can SET/GET/REPORT the year, month, day, hour, minute & second of the UTC time. However, it does not set the time zone which must be done via the Time CC V2. Thus, Time Parameters CC relies on the hub to send the current UTC time but the device can also send a GET and adjust its internal clock to match the one from the hub. However, this requires support on the hub software which is not mandatory so not all hubs will be able to provide the current date/time.
Clock CC – NOT Recommended
Clock command class is sent by a Hub and can set the local weekday and time. Thus, it only supports a 7-day schedule since it cannot set the date, just the day of the week. Typically, the Hub would send a Clock Set as part of inclusion in the network. Since the clock on the device will drift, the device must periodically send a Clock Get to the Hub and to maintain time accurately. This method is NOT recommended. However, on some old hubs this is the only method available.
Recommended Time Setting Algorithm
Wait for Inclusion into a Z-Wave Network
Wait for Security negotiation to complete
Send a Time CC DATE GET
Wait for a Time CC DATE REPORT for ~30s
If DATE REPORT arrives, Send a Time CC TIME GET and wait for ~30s
if the Time REPORT arrives then the date/time is now set and use Time CC for future clock adjustments
Exit the search for the local time
If Time CC DATE REPORT times out:
Retry 2 more times with random delay of a few minutes between each retry
During steps 3-6, If a Time Parameters CC SET or a Clock CC REPORT is received, use those to update the date/time but if a Time CC report arrives use Time CC
Send a Clock CC GET
If a REPORT arrives within ~30s then use Clock CC GET to update the date/time
If CLOCK fails
Send Time Parameters CC GET to get the current date/time
If those fail, there is no source for the current date/time, disable all scheduling features
Depending on the accuracy of the local clock circuitry, the functioning time setting command class should be used to update the local clock at a sufficient rate to match the desired settings. Typically, this would be once per day assuming a 100ppm or better 32Khz crystal is used for the 700 series low frequency external crystal oscillator (LFXCO).
Conclusion
End Devices should send a Time CC Date/Time GET shortly after inclusion in a Z-Wave network and then periodically send Date/Time GETs based on the accuracy of the real-time clock circuitry. Updating at 3:10am ensures the clock will be accurate to daylight savings time should be sufficient for a low-cost 32kHz crystal. The algorithm above works for just about any hub that has at least minimal support for time keeping.
You have a second MCU or other data files you want to update using Over-The-Air (OTA) via Z-Wave. How can you reuse the Bootloader firmware to verify the signature and decrypt the data?
The code to verify and decrypt the file already exists in the bootloader and is known good. Reusing the existing bootloader code is smaller and safer than re-inventing the wheel – or in this case encryption.
The attached project is a modified Z-Wave Door Lock Key Pad sample application that demonstrates how to OTA code/data other than the Z-Wave firmware. OTA of the Z-Wave firmware works in the sample application already – but first the encryption keys MUST be generated. See https://www.silabs.com/community/wireless/z-wave/knowledge-base.entry.html/2019/04/09/z-wave_700_ota_ofe-i00M on how to generate the keys. See the two .BAT files in the comments section which will run all the necessary commands for you. They are also included in this .sls file in the KEYS directory. You MUST create your own project keys to OTA either the Z-Wave Firmware or any other data.
To OTA other types of files you need to start with a binary file. Most microprocessor development environments will output a binary file so use that instead of a HEX file. If you have an Intel hex or Mototola S record file, use a utility like SREC_CAT to convert it to a binary file. SREC_CATcan convert just about any file type into any other file type. If the file is more than 200K bytes, you will need to break the file into 200K or smaller files and OTA each, one at a time. Doing that is beyond the scope of this project. Note there is no need to encrypt the file. We will be using Commander to sign and encrypt it using the keys generated here.
Theory of Operation:
Changes to the SSv4 DoorlockKeyPad sample project are indicated with the comment “AKER” – search for these to find what changed. You can also diff the files with a fresh copy of the DoorLockKeyPad sample app from SSv4. Most of the code to support OTA of an external processor is in this file. A few changes have been made to ota_util.c in ZAF_CommandClasses_FirmwareUpdate but these are expected to be included in a future release of the SDK (currently tested on 7.13).
Commander is used to generate a pair of public and private keys. The private key is then programmed into every device to be OTAed. Commander then encrypts and signs the binary file and wraps it with bootloader tokens. The gbl file is downloaded, the signature checked and the encrypted data is then passed to a callback function 64 bytes at a time. You then have to store the data or pass it to the external MCU. This example simply prints the data out a UART.
Procedure:
Step 1: Generate the keys
There two .BAT files in the KEYS directory for this project. These are windows script files. For other platforms you can easily convert them to the platform specific commands. See the comments in the files for more details. In a windows shell type: GenGblToken.bat This will use Commander to generate a project set of keys in the files vendor_*.*. Only execute this command ONCE. The same keys are used for the duration of the project. If you change the keys then you cannot OTA the devices as the keys no longer match.
Step 2: Program the key into a devkit and every DUT
Each device manufactured must have the private key programmed into FLASH. Use the PgmToken.bat to program the key into a target device connected via USB. Note that EVERY unit manufactured must have these keys programmed into it.
Step 3: Generate the .gbl file
Create the .gbl file from the binary file using the following command: commander gbl create <OTA_FileName>.gbl –metadata <BinaryFile> –sign vendor_sign.key –encrypt vendor_encrypt.key The –metadata option will wrap the binary data with the necessary tokens for the bootloader to parse the data. Do not use the –compress option. If the data needs to be compressed, use your own algorithm for that. There are 3 sample binary files in the KEYS directory – a small .WAV audio file, a large .M4A audio file and a PNG image file. Use the command above to wrap the file with the necessary tokens for OTA.
Step 4: OTA the .gbl file
Use the PC Controller or other application to send the gbl file over Z-Wave. Once the entire file has been sent and the CRC checked to be good, the FinishFwUpdate function is called to begin processing the image. Note that in the PCC you have to first GET the Current Firmware, then select the Target: 1 to download the metadata. Then click on UPDATE and the OTA will begin. Connect a terminal to the VCOM port of the WSTK to view the data streaming down during the OTA. Once all the data is sent down, the signature is checked and the decrypted data is sent out the UART. This is where you would need to change the code to store the data instead of printing it out the UART.
Step 5: Verify the Signature and pass in the callback function
The bootloader_verifyImage() function is called and the metadataCallback function is passed in. bootloader_verifyImage first returns a zero if the signature matches. If the signature fails an error value is returned giving some details on why it failed. The time to verify the signature can be fairly long depending on the size of the image so the watchdog timer is disabled during the processing.
Step 6: MetadataCallback passes blocks of 64 bytes of the decrypted data
The function passed in to bootloader_verifyImage is called with a pointer to the data and the number of bytes in each block. The size of the block can vary up to 64 bytes. In this example the data is simply printed out the UART. In your application you would replace this function with code to store the data as needed on the other MCU or external NVM.
Step 7: Reboot
It is recommended to reboot after the image data has been stored to ensure the FLASH is cleaned up properly. The current demo however does not reboot.
Note: This is an SSv4 SDK 7.13 sample but the same concepts should work in SSv5. The changes to ota_util.c will be folded into the SDK in a future release but for now those changes are necessary.
What does an SDO mean you might ask? An SDO is a Standards Development Organization and the Z-Wave Alliance has now legally become a non-profit SDO. What this means to you is that Silicon Labs no longer control the progress of Z-Wave, the members of the SDO now control it. Read more details about the SDO in the Z-Wave Alliance Press Release.
There are seven founding members: Alarm.com, Assa Abloy, Leedarson, Ring, Silicon Labs, StratIS, and Qolsys. If you’re employed by one of these companies, join a working group and make your ideas known! There are six different membership levels with varying “voting rights” and costs so your organization can choose a level based on interest and budget.
How will this impact you and your IoT device development? In the short term probably not much, early next year however, expect to see the first Z-Wave product pass thru the new certification requirements based on the specifications produced by the SDO. Longer term this is all part of Z-Wave becoming an open standard with more silicon providers and software stack provides implementing new features all to make Z-Wave last for years to come.
The goal is to make Z-Wave THE sub-GigaHertz radio standard for IoT devices. Z-Wave is simple, low power, doesn’t require a lot of FLASH/RAM (IE: it runs on cheap MCUs) and most of all interoperable all the way back to devices released over two decades ago. Sub-GigaHertz means the radio passes thru walls and travels longer distances with less interference than the 2.4GHz protocols.
I want to remind everyone to register for the Works With Virtual Conference coming up in just a few weeks! Click below to check it out – HEY it’s FREE!
Works With is much more than just Z-Wave. All the key eco-system players are there explaining in detail how to be a part of their world. This is a technical conference so don’t miss it. I’ll be giving a demo of the latest version of Simplicity Studio V5 and how to quickly build, debug and certify Z-Wave applications.
Silicon Labs is hosting what was intended to be an in-person conference in Austin Texas but is now a virtual online conference on IoT ecosystems – the Works WithSmart Home Developer Event September 9-10. The best part is it is now FREE to attend any of the in-depth technical sessions and you don’t have to wear a mask. The downside is that we don’t get to experience all that great music down in Austin – well, there’s always next year!
I am hosting the Z-Wave track and will be making several presentations including a detailed look at Silicon Labs latest release of Simplicity Studio V5 which just came out yesterday. We’ll also have presentations on developing Z-Wave Smart Hubs and Z-Wave Certification. I’ll also be describing some IoT failures – you learn more from your failures than your successes. We have speakers and engineers from all of the ecosystem partners, not just Silicon Labs folks. Learn from the experts from across the industry!
What is Works With 2020? The smart home developer’s virtual event where you will have the opportunity to interact with our ecosystem partners from Amazon, Google, Samsung, and Z-Wave to connect devices, platforms and protocols and be able to immerse yourself in keynotes, a panel discussion on Project CHIP, hands-on, and technical sessions led by smart home engineers who are building the latest advanced IoT devices. The Works With event is live, all-online, free of charge, and you can join from anywhere around the world.
Click here to Register Today and feel free to forward to the rest of your team.
Here’s an overview of what you won’t want to miss:
Specialized Engineer-Led Tracks – Educational sessions and technical training designed for engineers, executives, developers, business development and product managers.
Hands-On Workshops More than 12 workshops and hands-on sessions to give you experience, knowledge and confidence to develop and accelerate smart home development.
One-on-One Developer Meetings – Schedule a meeting with Silicon Labs or an ecosystem partner to get 1:1 technical guidance.
Join me in September and learn how to smoothly get your IoT device plugged into any and all of the ecosystem partners. Register today, it’s totally free and you can join from anywhere in the world. See you September!
One of the most common questions in embedded programming is “How much FLASH/RAM am I using?” or more precisely, “How much do I have left before I run out?” or even “How much do I have to squeeze my code to fit in the available space?” Yikes! Very often the code size quickly fills to fit the available space and then you start struggling to fit all the features in your product. This problem afflicts the Z-Wave 700 series just as much as any other IoT development. I’ll give you a few hints on tools to measure the code size and figure out where the bloat is and options to squeeze a little more code in.
ZGM130S Resources
The first step is to understand how much FLASH/RAM we have in the Z-Wave ZGM130S. Open the datasheet and we see there is 512K FLASH and 64K RAM. Seems like a TON! But wait, a closer look at the datasheet and there is a note that only 64KB FLASH is available for the application and 8KB RAM. That’s not a lot for a complex IoT device like a thermostat with an OLED screen but is plenty for a simple on/off light switch. Like any engineering trade off, the chip balances the available resources to match the most common use cases.
The Z-Wave stack isn’t huge so fortunately there is sufficient space available for most applications. However, the stack developers have reserved most of the the FLASH and RAM space for future upgrades. There is no easy to use tool that precisely measures how much code space is being used for the stack versus the application. In this post I’ll give you some tools to see how close you are to the total and then subtract a typical sample application size to find the amount your application is using. INS14259 section 5.1 gives the typical FLASH usage for the Z-Wave sample applications.
Half of FLASH (256K) is reserved for the Over-The-Air (OTA) firmware image. This block of flash is used when the firmware is updated and the data is stored here temporarily until the signature is checked and the code can be decrypted. Once that test has passed then the code is copied down into the normal FLASH space and the chip reboots into the new firmware version. If you need a lot more than 64K of FLASH you can consider moving the OTA storage from the upper half of the ZGM130S to an external serial FLASH. This is supported in the Silicon Labs Gecko Bootloader but requires some coding to free up all that space. This also requires hardware support for the external FLASH chip. So if you think you’re going to be short on code space, I highly recommend adding a serial FLASH chip even if you don’t use it right away. I plan to describe the OTA to external FLASH process in a future blog posting so stay tuned.
ARM Tools
Before starting with code size analysis be sure you are working with the “release” build and not the debug build. Click on Project->Build Configurations->Set Active and select the Release build. Then build the project. The debug build uses minimal optimization and has tons of ASSERT and PRINTF code in it which invalidates the code size analysis.
ARM eabi-size
When you compile a Z-Wave project it will run the arm-none-eabi-size -A <project.axf> command which prints out an obscure listing of the sizes of various FLASH segments. The DoorLockKeyPad sample application produces the following:
.text = code which lives and runs out of on-chip FLASH
.data = initialized variables
IE: int myvar=12345; results in 12345 being stored in FLASH and then copied to RAM on power up
Thus .data uses both FLASH and RAM
The other 2 segments are in FLASH space but subtract from the total available
.nvmApp = Application non-volatile memory
.simee = SDK non-volatile memory
RAM = .bss + .data
.bss = Variables not explicitly initialized
gcc normally zeroes on power up
.data = initialized variables
.heap = heap used for dynamic memory allocation
.stack = the stack for pushing return addresses, function parameters and other things
The other segments can be largely ignored
The available FLASH is 256K minus the .simee and .nvmApp=256K-12K-36k=208K
The available RAM is 64K minus the heap/stack=64K-3K-1K=60K
Thus:
FLASH=168760+1132 = 169,892 bytes = 80% utilized
RAM=28956+1132 = 30,088 bytes = 49% utilized
You can see that the SDK code and the application are all mashed together without a way to identify how much the application is using. But at least you know when you are running out. Note that each release of the SDK will change the amount of flash used by the SDK code and possibly the ZAF. Note that the ZAF is considered part of the Application code.
Commander Flash Map
Another easy way to check how much FLASH is being utilized is to use Commander to display a map of FLASH. Start commander and connect to the DUT then use Device Info->Flash Map to get a chart like this one:
ARM eabi-nm
If you want to know which functions and variables are the biggest chunks of FLASH/RAM usage use the nm command: arm-none-eabi-nm <project.axf> --print-size --size-sort -l | tail -30
Address Size Type Symbol
00018c84 00000444 t process_event
0001c760 00000454 T IsMyExploreFrame
000172a4 00000454 T TransportService_ApplicationCommandHandler
000185aa 000004d2 T S2_application_command_handler
0001de00 000004e4 T crypto_scalarmult_curve25519
0001098c 0000054c T IsMyFrame
00017ee4 00000590 t S2_fsm_post_event
00010318 00000674 T IsMyFrame3ch
20006c14 00000708 B channelHoppingBuffer
000138a0 000007e8 T CommandHandler
00021960 00000888 T FRC_IRQHandler
00011790 00000890 T ReceiveHandler
2000628c 000008ac B the_context
20007590 00000c00 N __HeapBase
00019788 00000e04 T mbedtls_internal_sha1_process
00026f68 000019cc T RAILINT_0cdb976df793f6799e20dfa42e2be4c6
00074000 00003000 b nvm3AppStorage
00077000 00009000 B __nvm3Base
00077000 00009000 B nvm3Storage
The third column need a little decoding: T/t=.text (FLASH), B/b=.bss (RAM) D/d=.data (both FLASH and RAM)
You can also tell if it’s FLASH or RAM by the address – FLASH starts at 0 and RAM starts at 0x20000000. Starting from the bottom of the list above you can see that the NVM3Storage is 36K which is naturally the largest block of FLASH. Followed by the 12K of NVM3 Application storage. From there the sizes drop fairly quickly but you can guess the function based on the name. RAILINT is a bunch of Hardware Abstraction Layer (HAL) code. mbedtls is the Security S2 encryption functions. The HEAP is the largest single block of RAM followed by “the_context” which is a fairly large structure the ZAF and the SDK use to store the security and routing information.
Now that you can see the heavy users you can see if there is something amiss. Perhaps a buffer can be reused instead of using unique buffers for various functions. Look carefully for any unused functions in your source code. GCC often will leave “dead” code in place because it can’t tell if you’re using it as a dynamic callback function so to be safe it leaves the code in there. Thus, review your code and make sure you don’t have dead functions or variables or entire buffers that are never used.
The most common method to squeeze more code in is to try various options in the GCC compiler. The more recent versions of GCC have added Link Time Optimization (LTO) which can significantly reduce the code size (claims are up to 20%!). Simplicity Studio is moving to newer versions of GCC later this year so more of these options will be available. Worst case is to refactor your code to make it more efficient or drop features.
Other Tools
There are other tools like Puncover and Bloaty which can help with managing code size growth. I haven’t personally tried these but they seem like they would help. If you use a tool that helps manage code/RAM let me know in the comments below. We all need help in squeezing into the available space which is never enough!
Z-Wave Virtual Webinar Wednesdays at Noon Eastern US time
Doctor Z-Wave will be giving a hands-on live demo of getting started using Z-Wave with Simplicity Studio on Wednesday June 17. This is a live demo with just a couple of slides so you don’t want to miss it. The session is a short roughly 30 minutes with time for Q&A afterward. I will show you some simple things on setting up Simplicity to make your life easier when getting started. If you can’t make it, it will be recorded and available via the Alliance web site.
There are lots of other topics for Webinar Wednesdays:
Webinar Wednesday Schedule*:*This schedule will be updated regularly on the Z-Wave Alliance website as the series progresses
May 27, 2020 Manufacturing During a Global Pandemic: Insight & Strategy from Companies Who Are Coping Hosted by: Avi Rosenthal – Bluesalve Partners
June 3, 2020Social Distance Sales for Uncertain Times: Tips & Insight for Integrators Hosted by: Jeremy McLerran – Qolsys
June 10, 2020Residential Smart Lock Market: Trends, Use-Cases & Opportunities Hosted by: Colin DePree – Salto Systems
June 17, 2020Z-Wave 700 Series: Getting Started Hosted by: Eric Ryherd – Silicon Labs
June 24, 2020 Feature of Leedarson Z-Wave 700 Series Security Products Hosted by: Vincent Zhu & Michael Bailey Smith – Leedarson
I’m giving a presentation on Z-Wave where you can ask questions and get answers about the opening of the Z-Wave specification among other topics. There are more Tech Talks scheduled and several recent topics were recorded. Follow the links below.
Good news! We have added new Tech Talks. Join us on Tuesdays and Thursdays for live virtual, technical discussions hosted by a lead engineer with time allocated for your questions. We’ll cover topics like battery optimization with BG22, using Z-Wave for your Smart Home Solutions and more. You don’t want to miss these next talks.
Register by clicking here: Tech Talks: Z-Wave Smart Home Solutions by Doctor Z-Wave Tomorrow April 23 at 4 p.m ET
Battery Optimization with BG22 Tues, April 28 at 3 p.m. CT Max Performance on BLE – Simultaneous Connections, Beacons and Scanning Thurs, April 30 at 3 p.m. CT SubGHz Proprietary and Connect Software Stack Tues, May 5 at 3 p.m. CT How to Measure and Debug Network Performance – Using Silicon Labs Network Analyzer Thurs, May 7 at 3 p.m. CT
Good news! We have added new Tech Talks. Join us on Tuesdays and Thursdays for live virtual, technical discussions hosted by a lead engineer with time allocated for your questions. We’ll cover topics like battery optimization with BG22, using Z-Wave for your Smart Home Solutions and more. You don’t want to miss these next talks. 
DrZWave 