The ATOM Lite has a 5V output for the GROVE port but the esp32-pico-d4 uC datasheet says the max digitals high level input is VDD+0.3. The ATOM Lite is powering the ESP32 with 3.3V so that means the max voltage on the i2c SCL & SCA pins would be 3.6V.

Why does the ESP32 output 5V on the GROVE port it if can't accept 5V digital inputs. Do all i2c devices require their own 5V -> 3.3V step down converter then?

I am unable to get the LED Show example for the AtomS3 to compile, well any of the examples for that use the serial port. I followed these instructions. I am running Arduino IDE 2.2.1 on windows 11 with the M5 Stack library and the M5AtomS3 board selected in the IDE. Looks like it cannot find the definition of USBSerial as the error states "Compilation error: 'USBSerial' was not declared in this scope"

In file included from c:\Users\Luke\OneDrive - Luke\Documents\Arduino\libraries\FastLED\src/FastLED.h:75,
                 from c:\Users\Luke\OneDrive - Luke\Documents\Arduino\libraries\M5AtomS3\src/M5AtomS3.h:8,
                 from C:\Users\Luke\AppData\Local\Temp\.arduinoIDE-unsaved2023109-47808-1drqtel.cea6\sketch_nov9a\sketch_nov9a.ino:15:
c:\Users\Luke\OneDrive - Luke\Documents\Arduino\libraries\FastLED\src/fastspi.h:157:23: note: #pragma message: No hardware SPI pins defined.  All SPI access will default to bitbanged output
 #      pragma message "No hardware SPI pins defined.  All SPI access will default to bitbanged output"
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C:\Users\Luke\AppData\Local\Temp\.arduinoIDE-unsaved2023109-47808-1drqtel.cea6\sketch_nov9a\sketch_nov9a.ino: In function 'void setup()':
C:\Users\Luke\AppData\Local\Temp\.arduinoIDE-unsaved2023109-47808-1drqtel.cea6\sketch_nov9a\sketch_nov9a.ino:23:5: error: 'USBSerial' was not declared in this scope
     USBSerial.println("Pls Press Btn change color");
     ^~~~~~~~~
C:\Users\Luke\AppData\Local\Temp\.arduinoIDE-unsaved2023109-47808-1drqtel.cea6\sketch_nov9a\sketch_nov9a.ino:23:5: note: suggested alternative: 'Serial'
     USBSerial.println("Pls Press Btn change color");
     ^~~~~~~~~
     Serial

exit status 1

Compilation error: 'USBSerial' was not declared in this scope