HMI module with M5Stack Basic V2.7 - Grove Port C

  • I had my wires plugged into pins 16 (RX), 17 (TX), and Ground on the M5Stack Basic V2.7 for some serial communication with a camera lens motor. This was working fine when I setup Serial2 with:

    Serial2.begin(115200, SERIAL_8N1, 16, 17);

    I have attached the HMI module to the M5Stack Basic V2.7 and I've soldered my wires to a grove cable utilising the white (for RX), yellow (for TX), and black (for Ground) with red being unused. I have plugged this grove cable into Port C on the HMI module (as I understand it's for UART communication). According to the HMI documentation the RX should be pin 16 and the TX should be pin 17 on the M5Stack Basic, which matches what I had coded originally (Image showing the pin allocations here

    However, my code does not work now. Am I missing a step? Do I need to do anything differently in my code?

    I saw the HMI example code on the GitHub repository (, however that example was for the buttons and rotary encoder which I'm not using for the time being (so I haven't included the MODULE_HMI.h/cpp files).

    Any help would be appreciated as I'd like to the the grove connector rather than individual pins. Thanks!