ESP32 Forum

Posted: **Thu Mar 02, 2023 2:43 am**

Hello

I have equipment transmitting via uart with a baud rate of 1382400 and I would like to read this information through the Serial2 port of the ESP32.
i'm using arduino ide to program and I've tried to set this high baud rate using Serial2.begin(1382400) but I can't read anything.
Using the function to detect the baud rate I found a maximum of 922190 bauds.
Below is the sketch I used to check the baudrate:

Code: Select all

void setup() {
     Serial.begin(115200);
     delay(100);
     Serial.println();
     Serial2.begin(0, SERIAL_8N1, -1, -1, true, 11000UL);  // Passing 0 for baudrate to detect it, the last parameter is a timeout in ms
     unsigned long detectedBaudRate = Serial2.baudRate();
     if(detectedBaudRate) {
       Serial.printf("Detected baudrate is %lu\n", detectedBaudRate);
     } else {
       Serial.println("No baudrate detected, Serial1 will not work!");
     }
   }

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

}

The answer I get is as follows:
Detected baud rate is 922190

I managed to communicate between the equipment and the esp32 using a baud rate of 115200.
I changed the baud rate to 230400 and I couldn't communicate anymore. From 230400 no baud rate worked.

The transmitting equipment uses pic 18F4520 and engineering sent me the following information:

The crystal of the equipment is 11.0592 MHz
The PLL quadruples this frequency, so the pic's clock is 44.2368 MHz.

I connect the tx with the rx , I interconnect the GND. As far as I understand it is not a connection problem because in 115200 bps it works.
Unfortunately I can't change it to 115200 definitively because it changes other functions of the equipment.

Is this a limitation of ESP32? Could I do something else to test?
Sorry for the long post and language mistakes as English is not my main language and this is my first post too.

ESP32 Forum

Baud rate above 115200 doesn't work using esp32

Baud rate above 115200 doesn't work using esp32