Increasing external I/O connection/replacing M5GO on Fire

[mcbridejc]

Hello,

I just received my Fire! In pictures, I saw rows of headers on the sides of the enclosure; now I see that this was for other models, not the Fire. On the Fire, there are very few externally connected processor pins. Is there a board I can buy to replace the M5GO board (the one with the battery) to provide these header breakouts? A battery isn't too important to me, but with only 4 externally connected pins I think this will be next-to-useless as a development board.

Thanks,
-Jeff

[Dreitagebert]

I have a 'normal' M5 and a Fire. If i need the pins for testing and rapid development i do change the backside.
And i have bought some pure Pcb for the M5 which you can simply plug in instead of the backside.

[mcbridejc]

Hi Dreitagebert,

Thank you for confirming they are indeed swappable! I was hoping to buy just the backside board, but I'm not seeing it anywhere. Actually, I haven't found a schematic for it anywhere either, I just assume it must exist because of the photos!

I'm finding it a bit confusing to find schematics for a particular product. I.e., the schematic for the "M5 Core" on github appears to be for all the varieties of cores? Except it doesn't include the MPU9250 on it, which some varieties are supposed to have, so I expect there are other schematics, either not published or that I just haven't found yet.

[m5-docs]

@mcbridejc

Hi, We will put on sale a new product named "Bus" which is aimed for developers to expand I/O.

And here's the difference between with all cores. Maybe help you.

https://github.com/m5stack/M5-Schematic/blob/master/Core/hardware_diff_between_m5cores.md