When I started building microcontroller projects, I wanted to be able to easily be able to replace modular parts and also avoid the mess-of-wires builds. I was initially looking at using arduino pro minis and designing boards that they plugged into, but they weren’t a super great fit for me. I wanted to easily plug NRF24L01 radios into my projects, and using the pro mini meant I’d have to break out the pins for it on every board. Also, I was after more generic and modular boards rather than having to design one for every use case. Maniacbug’s sensor node design inspired me and I started designing microcontroller boards with 2×5 connectors for connecting daughter boards with various sensors on them, as well as a built in socket for the NRF24L01 module.
While I got to a point of having some polished designs that I was quite happy with, I did come upon a couple of frustrations about the form factor I’d gone with. I found that it was awkward when the things I was connecting needed spi or uart as they weren’t on the connector, and that I was having to work out how to get 5v or battery power to some sensors instead of just the 3.3v. Having the mounting holes on either side of the connector wasn’t great for stability and it was awkward trying to work out enclosures given that the daughter boards all stuck out of the main board’s footprint. Around this time I noticed the Adafruit Feather boards and realised that I could redo my boards using the Feather footprint and get most of the capability of my design while fixing a couple of its failings. The best thing was that I would be able to buy other boards that would be compatible with my boards and not have to design them all, while also being able to share my boards for other people to easily be able to use with their own Adafruit Feather products.it didn’t take long to convince me, and I now have 10 of my own Feather-compatible boards designed and here/shipped. Here’s the new AtMega328 + NRF24L01, more to follow.