pictographer
Senior Member

A second Teensy would allow you to avoid 'impossible' programming. Just plug in the one you want to use.

I don't see you setting the input more of any of the pins. You might need to configure the inputs to use pull down resistors so they don't float and give occasional wrong values.

The big selling point for RISC-V is that it's open source. If the PJRC variant were not entirely open, that would make it less interesting. The world would be a safer place if there were more computers and especially...

Probably the easiest way is to combine them and add a new definition for the setup function that runs one or the other based on your choice.