IoT Device Testing Best Practices by Eric Ryherd
Click HERE to see the entire presentation including my notes. If you are a Z-Wave Alliance member a video of the presentation is usually posted on the members only section of their web site. The main takeaways from my presentation are:
- Have a written test plan
- Use the Compliance Test Tool (CTT) as the START of your test plan
- Vary the environmental conditions during testing
- Test using real world applications
- Test using complex Z-Wave networks with routing and marginal RF links
- Test with other hubs and devices
- Automate testing using tools like the ZWP500
- Code firmware with failure in mind
- Utilize the WatchDog timer built into the Z-Wave chip
The presentation goes into detail on each of these topics so I won’t duplicate the information here. I also go thru several failures of devices I’ve been working with. You learn more from failures than you do when everything just works. This is the same presentation that gave last fall in the US summit.
Z-Wave Summit Notes
There were nearly 200 attendees at the Summit – a significant increase over last year. One of the main purposes of the summit is to learn what’s new in Z-Wave and what Silicon Labs is planning for the future. The most important news at this year’s summit is the 700 series which was announced at CES in January. Unfortunately we will have to wait a bit longer to get our hands on the chips due to the purchase of Sigma Designs by Silicon Labs. The 700 series chip has been updated to match the other SiLabs microcontrollers so the silicon has been delayed a bit but they expect to ship parts before the end of 2018. Z-Wave will benefit tremendously from a real CPU instead of the very resource constrained 8051 in the 500 series. The feature I can’t wait for is the hardware debugger. We’ll finally be able to single step our C code and inspect variables and set breakpoints. No more PRINTF! Yeah!
Time for hubs to switch to Z/IP and ZWare
The very clear message of the summit is that Z/IP and ZWare are now mature and is THE gateway interface going forward. My initial brief trials with Z/IP were frustrating with poor documentation and the software really wasn’t quite ready. But with the recent release of 2.81 it would appear it is ready for prime time and I’ll have to give it another look. I was surprised by the number of gateway developers that were at the summit and most were already using at least Z/IP and many also using the ZWare abstraction layer. The SerialAPI is the interface most gateway developers have used in the past but this is a very low-level interface. There are many nuances of handling sleeping devices and the complexities of the encrypted security encapsulation when using such a low-level interface. This is where Z/IP comes in which handles nearly all of these lower level details for you. Z/IP is planned to be the only supported interface in the near future and certification costs will be significantly higher if it is not used. ZWare adds another layer on top of the Z/IP which provides much easier C++ objects relieving the developer from having to learn the details of each Z-Wave command class. See the Z-Wave Public web site for more details.
The internal Z-Wave Technical Site (ZTS) is now also available to everyone but you still have to click on “accept terms” to gain access. However the access is granted immediately so you don’t have to wait for “approval”. So anyone wanting to learn about the inner guts of Z-Wave can now do so without buying a DevKit.
Summit isn’t all work, work, work
The Summit isn’t all work all day even though the days are long and filled with lots of technical information. This summit had an evening at the Rosarium park. The park has room for team building games like a maze run, archery, volleyball among other games and of course lots of food and drink. It was a nice ice breaker and a good way to get to know your fellow Z-Wave developers. The networking opportunities are a very large part of the value of attending the summit in person. The evening highlight was a performance by the “Interoperables” Z-Wave Rock and Roll band lead by Alliance chairman Mitch Klein.