I have a Arduino Pro Micro and use the USB port for programming. Is it possible to use the hardware serial port for connecting with a peripheral while I'm using the USB port (and hence the hardware serial port) for programming? Or must I disconnect the USB cable or otherwise reconfigure the hardware?
I have a Teensy 2.0 with a ATmega32u4 and I can use both, with the USB as Serial.* and the hardware UART as Serial1.*
For the Arduino Pro Micro it is the same. See Arduino Pro Micro, get data out of Tx pin?
For Teensy, see https://www.pjrc.com/teensy/td_uart.html
