|Product Performed to Expectations:||10|
|Specifications were sufficient to design with:||10|
|Demo Software was of good quality:||10|
|Product was easy to use:||10|
|Support materials were available:||10|
|The price to performance ratio was good:||10|
|TotalScore:||60 / 60|
This is a review of the ON RSL 10 Sensor Development Kit. I received this a bit late, due to some clerical error between myself and Element, so I didn’t actually start work on it till early December, 2019
Although I work for a public utility, the department I’m in is more of a R&D setup. Specifically we are charged with evaluating products that either help consumers reduce/manage their energy better, and/or help the company more efficiently deliver power. Part of the various ongoing projects include instrumenting real customer’s houses in order to gather data.
A current project that I’m the lead engineer on is evaluating how residential battery systems perform given our weather (I’m based in Phoenix, AZ, where during the summer, we have very high temperatures for long durations, plus high UV index). Part of this project is to put temperature/RH sensors on customer’s houses so we can get environmental data, along with usage data on the battery, etc.
Initially, we were doing a zwave based temperature sensor, but we are now looking for a different sensor that is wireless. This is mostly because a lot of our customers do not want to see wires in their garage, etc, even though we install professionally, and as part of the study, will take everything down. So, when I got a chance to review this development kit, it seemed very appropriate.
I won’t go thru the normal set of pictures unboxing the device, as there are plenty of those elsewhere. What I did observe was a nice small device, with the flexible antenna. Foot print is great, only about 2.5 inches in diameter. The flex antenna is interesting in that it’s designed to be folded back over the battery, so if needed, can be placed in an enclosure. Same time, its not apparent how long that will work without one of the leads breaking.
The first thing I did find when starting to set up the development machine, is that ON apparently reorganized their documentation suite, and their software components sometime in September 2019. I found this out, as the userguide that is on the Element site refers to the older setup. This took me a couple of extra hours to chase down all of the right pieces and get the development setup correct. For reference, the latest user guide is here: https://www.onsemi.com/pub/Collateral/EVBUM2614-D.PDF
Once that was done, running the demo software was very straight forward. No issues following the examples, and on the bench, everything worked as it was supposed to. Time to deploy.
For testing purposes, I deployed this on an existing H-frame setup at our test facility. This is a covered frame where we house a couple of different battery/inverter systems. It is outside exposure, with lots of metal around, so for me this is a somewhat extreme test local, especially for the blue tooth signals.
I deployed it initially, just taping it to the frame (see picture):
I did basic tests in terms of reading it from the mobile app that ON supplied and the tests were all successful. A bonus was it even measured the vibration caused by the structure.
As show in the next picture, there is a lot of metal around the unit. However, on a range test, I was able to read the device, repeatedly from up to about 5 meters away, in all directions. Given the other sources of interference, this was a very good result.
The device has now been running for about a month, and it is still going well. The weather has been cold (at least for Phoenix) but there has been no apparent issues with the device. (Note, I have a separate Bluetooth device that pings the RSL every minute or so, so I can effectively datalog).
Being winter, I can’t test for heat, but that will be next summer. I have put the device in na outdoor rated ABS plastic jbox, and that did not affect the range of the blue tooth signal.
I really liked this device, especially from a dev kit perspective. It’s simple to program (once I got the right setup), and it does work. I’m considering buying a few of these, and just using them as my temperature sensors on some house’s rather than designing my own specific board. I like ON’s documentation, and their approach to this. From an enclosure perspective, we will probably have to 3D print them, as I haven’t been able to find a small round enclosure that is outside rated (yet).
Thank you to both ON Semiconductor and Element 14 for letting me have this sample to use and try out.