hardware serial questions


I want one Arduino to send serial data to another Arduino.

  1. Is this possible while both are powered by the USB cable from the PC?
  2. Can the PC upload the sketches while the serial ports of the two Arduinos are connected to each other?
  3. If one Arduino is busy while the other is sending serial data to it. How much can the buffer hold?



I'm not sure but I think:

  1. Yes as long as there is no serial communication with the PC
  2. No unless you have an Arduino Mega and use the additional Serial IO's (e.g. Serial1) for communicate between Arduinos
  3. The buffer is 64 chars on Arduino Mega, not sure for other Arduinos.

I think in your case if you don't have a Mega then you should try SoftSerial.

Someone correct me if I'm wrong :slight_smile:

you can connect the two arduinos with software serial and keep the usb connections to both. I have done this. run two instances of the IDE and verify that the serial ports for each arduino is correct in tools>>serial port. you can open the serial monitor in each IDE and use them for troubleshooting