This is just a quick post showing the newly arrived PCB’s. I have only found a few errors in the board where the STM32 Nucleo Expansion port didn’t have some signals that I assumed. Luckily I added enough 0 ohm resistors and work arounds so that it won’t be a problem. (Latest schematics on Github show the changes in the Develop Branch). I discovered the problem when adding OneWire support for the DS18B20 temperature sensor. Once I get all of the other sensor ports working I’ll flush out any other unexpected behavior and keep the schematics updated as I progress.
I got 10 of these boards for about $20 so it was a really good deal. These boards were made in Kicad and the designs and all source code is available on github as explained in this post.
After attending Embedded Systems Conference this past week, I’ve got quite a few new ideas to making these sensor nodes firmware more robust, with licensing terms that will allow me to use the software I create in open source projects as well as closed source.