Undefined reference to UART_USB

Development Tools IDE 2.x
1

I am working in IDE 2.3.6 (Win11) with an Arduino Giga R1 WiFi board.
This has been going well until I updated the board package to rev. 4.3.1; now I am getting this error:

In function `setup':
C:\Users\james\AppData\Local\Arduino15\packages\arduino\hardware\mbed_giga\4.3.1\libraries\RPC\src/RPC.h:77: undefined reference to `_UART_USB_'

This seems to be related to using Serial and Serial.print(), etc.

What do I need to add/modify to handle this undefined reference? (moving back to the prior board package works alright, but I don't like being behind in updates)

Thanks in advance.

2

Hi @jstan01. Does the error still occur when you compile this simple sketch?:

#include <RPC.h>
void setup() {}
void loop() {}
3

Oddly, it seems to be working now. I've gone back and forth between the current version of the library and an older version a few times this morning -- maybe I finally got something right.

Otherwise, it did build using "RFC.h" with no problem as long as the code had no references to Serial -- I commented out Serial.begin and Serial.print to get it to link. For some reason, that is working now with references to Serial uncommented.

Sorry for the inconvenience -- it's clearly working now that it knows you're looking. Thanks very much.

4

Thanks for taking the time to post an update! Even though it isn't as satisfying as determining the cause of the error, at least we can be glad it is working now.

Regards, Per