Hi community, I have a few questions about a custom PCB I'm designing. It has the ATMega32U4 MCU onboard and I had planned on purchasing chips pre-loaded with the Leonardo bootloader to avoid the need for ICSP pins on my PCB, to save board real estate.
I'm actually using the ProMicro bootloader in development. Are the pin assignments the same as the Leonardo?
If not, then I need to program the ProMicro bootloader in. Can this be done via USB alone? I also want to eventually set the appropriate fuses later so the user code cannot be over-written.
For these reasons, must I provide ICSP connections in my design or can the tasks above be achived solely over USB? As stated I am just trying to reserve PCB space. But if ICSP is absolutely a must then I'll find a way.
Any advice much appreciated !