Protect GPIO Inputs and Outputs

[RussellPiBot]

I plan on building a Pi B+ GPIO breakout board to serve as an interface between the Pi and bot circuits to include: motor control, servo control, sensors, etc.; basically bot build-outs that may damage the bot because of my mistakes, ckt. failures, etc.

Ideally, I envision the breakout board to include voltage dividers, level shifters, a micro-processor to generate PWM and anything else that makes sense.

The breakout board will be designed to sit on top of the Pi similar to a Pi-hat or Arduino shield.

For me a lot of the fun from any project comes from planning, building circuits and then making it work.

Any help you may provide to point me in the right direction, make good choices and in general avoid major screw-ups would be appreciated.

Regards,

[BAStumm]

In my opinion, something lacking in add-on boards for RPi is optocoupling for the GPIO pins. I realize it is hard to envision what one might do with the RPi P1 Header pins but having protection via an addon board for at least some of the pins makes sense to me.

Other things you might consider are analog, expansion I/O (with opto?) and relays.