Pro Nano Choice?

I am not complaining - I am curious why the nano was chosen for the header at the top. Hopefully this question is not easily answered with a cursory glance at the docs.

Anyway, I realized shortly after receiving JL that the Arduino boards that I bought 5 of when they were on sale a few years ago were the micro - not the nano. The only nano I had on hand I realized is the esp32. I have ordered a few more decaf nanos, but I did want to ask - are all boards form the Arduino Nano family compatible? Would it make sense to generate some adapter PCBs for other board types - mainly I am thinking about cheap esp32 dev boards or perhaps a Pi0. I guess it comes down to the ? - what is the intended purpose of the top area headers?

I chose the Nano footprint because it’s the closest to a “standard” in the dev board world I could think of. You can get just about any microcontroller in that same footprint and the pins are usually in the same places.

The ESP32 nano will work fine, the only thing that won’t work with them is flashing code via the same USB cable because the ESP32 needs a sequence of reset pulses, but I’m working on support for that.

The Pro Micro will work as well, but you’ll need to cut the solder jumper RESET 1 because it’s tied to ground in the pro micro, and that’s connected to the other reset pin, RESET 0 so it will hold the board in reset and it won’t do anything.

Here’s where that trace is.

Then just put the board into the header all the way to the right.

There is some plans to make some expansion boards for the headers. If there’s a particular board you want an expansion for, put it in this sheet and I’ll make them when I get around to it pretty soon.