Matrix user forums

Hi,
Im trying to use the USB serial coms macro to communicate between the arduino UNO and a Rasberry Pi

The test programme is very simple, just flashing an LED. Without the usb serial initialise macro, programme compiles to chip and works, but as soon as I add the usb serial initialise macro, the system will not compile to hex and displays the attached error message. Am I doing something wrong?

Regards,
Chris

Last time I checked the controller of the uno did not support USB. The USB serial on the uno is a separate chip which is connected to RX/TX of the controller (atmega328p).

Yes Kersing is right, you need to use the UART component rather than the USB Serial component on the Arduino Uno board.