I checked with my Hello World code and this worked.

I did not expect the AtomS3 to be that different to the original AtomMatrix. However I just confirmed if I change the "board" to just M5Stack-Atom all the original code compiles.

I would have expected big changes if we referred to the ESP32-C3 with the new RISC architecture, but the S3 was fairly similar I thought.

I presume it has a new board definition due to the LCD screen on the AtomS3. If I can get the Zigbee unit working nicely, I might port the example over and post up a PR in the AtomS3 library.

Many thanks again @flypeek you have unblocked me and I can keep moving forward (I hope).

#include "M5Stack.h"

void setup() {
  // put your setup code here, to run once:
  printf("Hello World");
}

void loop() {
  // put your main code here, to run repeatedly:

}

Still produces the same exception above:

In file included from /Users/z/Documents/Arduino/libraries/M5Stack/src/M5Display.h:8,
                 from /Users/z/Documents/Arduino/libraries/M5Stack/src/M5Stack.h:111,
                 from /Users/z/Documents/Arduino/M5Stack_Hello/M5Stack_Hello.ino:1:
/Users/z/Documents/Arduino/libraries/M5Stack/src/utility/In_eSPI.h:633:20: error: 'VSPI' was not declared in this scope
     uint8_t port = VSPI;
                    ^~~~
/Users/z/Documents/Arduino/libraries/M5Stack/src/utility/In_eSPI.h:633:20: note: suggested alternative: 'SPI'
     uint8_t port = VSPI;
                    ^~~~
                    SPI

exit status 1

This is using Arduino IDE 2.0.4 trying to compile for M5Stack-AtomS3 board