ATmega32U4 to Arduino

Using Arduino Microcontrollers
1

Hello,

I have created a custom PCB with a factory version of the ATmega32U4 which I would like to flash with an Arduino program. I've created an Arduino sketch to interface with a UART device and successfully tested it on an Arduino. However when I program the same sketch onto the custom PCB with factory ATmega32U4, the UART communications don't work. I am able to have the ATmega32U4 print to the Serial port and read it with my computer. I have updated the fuses to match the Arduino Leonardo. Is there anything else that I'm missing that is necessary to flash a brand new ATmega32U4?

Thanks for your help!
Mike

2

Hi Mike,

Welcome to the Forum.

The 32U4 has an onboard USB to serial converter to talk to your computer (via the serial monitor, I presume you are referring to that). That connection is addressed as Serial, you say it works fine.

When you now connect a UART device, via Arduino pins 0 and 1 (physical pins 20 and 21 on the chip) which I presume you are, you need to use Serial1 to talk to the connected device.

Hope that addresses your problem.

Willem.