I'm assuming we're happy to be merging to master?

I would say that it definitely qualifies as a bug fix, so yeah, it should.

@drashna @megamind4089 @zvecr

Why was this removed? Almost every keyboard I have using the stemcell uses these pins. What is the alternative to utilize these GPIO when using a stemcell?

Edit: Note that I have 100 users or so who use these keyboards with a stemcell as well.

see #18236 (comment) - I have the same issue with that as this one...

Almost every keyboard I have using the stemcell uses these pins

Then they are not "pro micro compatible" and your issue extends out from the currently implemented converter targets.

Then they are not "pro micro compatible" and your issue extends out from the currently implemented converter targets.

@zvecr - This doesn't address my point in the other PR ( 18236 )...

The architecture of "from pro micro" (which is implicit at this point, since the build syntax doesn't support a from parameter) doesn't make sense. You know the target hardware, you know the pinout. Your refusal to support the bottom pins is based on the underlying (edit: qmk) architecture, which is irrelevant for the consumer. They have X number of pins, they want to use them. Why limit it?

But it is relevant to the consumer. How would a user use the converter feature to put a kb2040 into something that expects an elite c and use of its bottom row of pins? We know the pinout in both cases, but they are physically incompatible. The interface advertised, ensures that these scenarios fail for a predictable reason. The reason for this PR was to address the incorrect assumptions that unfortunately include your use case, before they start to duplicate everywhere and become a maintenance issue.

As mentioned in the other ticket, it does support a "from". The default is just currently "promicro" to maintain existing compatibility. Adding in an elite_c -> stemcell converter and updating PIN_COMPATIBLE for affected boards would be the way forward. The intention is that longer term, keyboards define what dev board they use. That way we can enforce someone trying to use converters on something like a dz60.

Outside of converters, there is no limit to pins. Some choose to add "first class" support as a keyboard sub revision to directly control items like low level driver config.

This translated into a discord conversation. For future reference (if needed):
https://discord.com/channels/440868230475677696/1017176320318373939/1017178935668265061