Why can't the RX pin receive inputs from computer and Bluetooth simultaneously

I have a Bluetooth module connected to the RX pin of my Arduino. When the board is connected the I am unable to communicate to the board via the serial monitor on my computer; only through the Bluetooth board. What is stopping me from communicating to both at the same time; is this hardware or the firmware on the Arduino?

Thanks for any explanation to why this occurs :slight_smile:

A serial connection is normally to connect only 2 devices together, and not more than 2. With that said, sometimes you can connect the bluetooth module RX and TX lines through 1K resistors, and then both the bluetooth and USB connections will be able to communicate with the Arduino processor. Both the serial monitor and whatever is at the end of the bluetooth connection should not send to the Arduino at exactly the same time or the signal will be garbled. Your mileage may vary, this is not something you are normally supposed to be able to do.

To keep it simple, you're basically are asking why two people can not watch different TV programs at the same time on the same television screen.

I have no idea about the bluetooth board but you probably can connect the bluetooth board's TX and RX to two other pins of the Arduino and use SoftwareSerial.

Okay thanks. I will try softwareserial for cases like this. :slight_smile: