Core2 + RS232F Module 13.2 UART2 not possible?

  • I have looked at the examples and the flow example indicates using uart2 and pins 16/17 on M5Stack Core.
    But according to documentation it is not the same pins for Core2 where uart2 is on 13/14 but pin 14 TX is not selectable on the dipswithes.

    I tried to use UART 1 on 1/3 but I have some issues with baud setting up 9600/7/1 None correctly on this port I think, and if I connect usb it stops working so...

    What am I doing wrong? Has anybody used the RS232 unit with core2?

  • Hello @Hnerik-Schmidt

    have a look at the topside of the module where the different GPIOs for different cores (M5Stack aka Core; M5Core2 aka Core2; M5CoreS3 aka CoreS3) are explained.

    Note: The dip switches are labelled for M5Stack (Core) only.

    So in order for M5Core2 to use GPIO13 and GPIO14 you'll need to set dip switch GPIO16 and GPIO17 to on.


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  • Ok so I might maybe probably have figured it out now.
    I compared the GPIO pinout of core and core2 and they have moved the pins on core2 to corespond to the same pins so what was said earlier that I should dipswitch the rs232 thing to 16/17 is correct.
    but at the same time the program should say 13/14. then it seems to play nicely,

  • Hello @Hnerik-Schmidt

    correct. I know it is a bit confusing. Most (if not all) modules have their GPIOs labelled for M5Stack (Core) and need some 'translation' when used with M5Core2 (Core2) or M5CoreS3 (CoreS3).

    Note: M5Core2 (Core2) has internal PSRAM and while most ESP32 GPIOs can be reassigned for various functions, PSRAM can only be used with GPIO16 / 17. That is the reason M5Stack engineers replaced them with GPIO13 / 14 on the M5Stack bus.