Maximum serial speed limited to 500000 baud?



  • Can somebody confirm that the maximum "Serial" speed is limited to 500000 baud?
    As soon I set it to 1000000 or 2000000 it stops outputting to the console.
    I have another ESP32 board, which is using a CH340 as UART-USB bridge, and this one is working fine on 2000000 baud.
    Is it a limitation of the CP210x chip used in the M5Stack?
    I'm using a M5Stack Grey.

    Working:

    void setup() {
    M5.begin();
    Serial.begin(500000);

    Not working:

    void setup() {
    M5.begin();
    Serial.begin(2000000);

    Thanks!



  • I stumbled on this restriction again, and dug a bit deeper in the issue.
    It appears that the hardware is not limiting the baudrate, but the M5Stack library. More specifically, M5.begin();
    Luckily, you can skip the UART init, and do it yourself like this:

    M5.begin(true,true,false);
    Serial.begin(2000000);
    Serial.flush();

    And now it works for 2000000 baud.