Makes sense why they can't both be connected. Now I need to figure out how to isolate the BT module and the FTDI interface when the FTDI interface is in use.What is the 'standard' way to prevent cross talk? Put diodes on both the FTDI and BT RX/TX lines, or something more clever?
I think I may have got it! I was able to fit a 2-pin 0.1" header right near the 3.3V power line, with the idea being that when the user wants to use the FTDI interface, they can remove the jumper and cut off power to the Bluetooth module. Would this solve the RX/TX conflict issue and protect the Bluetooth module?Not sure, as having active voltage on a input pin while the device is powered off can cause the device to try and power up through the input pin. It's called finding a 'backdoor circuit' and can cause real problems. Check out the wired-or solution posted.LeftyIn the attached screen shot, the new header is in the top left, just next to the Bluetooth module.