ESP8684 Terminal output baudrate error

[tim8656]

I have an ESP8684-DevkitM-1-H4 and I have installed ESP-IDF 5.0.

Using the Espressif-IDE, I created the blink example for the esp32c2.

Although the LED flashed, the 'on' time seemed slower that the 250ms programmed and the serial output appeared as garbage. Using an external RS232 terminal, I tried various baud rates and was unable to find any setting that decoded the output correctly.

For comparison, I connected an ESP32 module and rebuilt the project for ESP32. This time the LED flashed at the expected rate and the serial output was readable at 115200.

This suggests that the processor speed is being incorrectly handled by the esp32c code in the IDF.

Has anyone else observed this and is there a fix?

[WardMas]

Hello,
I am encountering the same problem with ESP32C2 but with a different module. Have you solved the problem ?

I could catch the board rate to be 75000 although it is set to be 115200 from the menuconfig.

is it a bug in the ESP-IDF v5.0?

[ESP_Sprite]

I think there's an ESP-IDF option to set the crystal speed; it can be 26MHz or 40MHz. Is that set properly?

[WardMas]

Hi ESP_Sprite,
Yes you are right. I have changed to XTal option to 26MHz and every thing worked properly. I didn't know that there is a such option. Thank you ESP_Sprite you saved my day.

For anyone having the same problem:
Component config -> Hardware Settings -> Main XTAL Config
then you can switch between 40MHz (default) and 26MHz

ESP32C2 uses 26MHz crystal so adjusting this option is a mandatory.

[andreko]

Hi,
I was really happy to find this forum entry, because I have the same issue with an out-of-the box ESP8684 DevKitM1 v1.1
So I followed the instructions above and changed the xtal frequency to 26MHz. Unfortunately this did not change a thing after a complete rebuild. I was digging deeper and opened the sdkconfig file in an editor and found the following two entries:

#define CONFIG_ESPTOOLPY_MONITOR_BAUD 74880
#define CONFIG_ESP_CONSOLE_UART_BAUDRATE 74880

Which sets exactly the baud rate that I also measured with a LA. If I open the sdkconfig in Eclipse IDE editor I can not find a section where I can change that baud rate. If I do it manually in the sdkconfig file myself, it will be overwritten on the next build.

Is there any other location where this weird value comes from?
Strange enough, if I use the dev kit without loading my own application it also starts with this weird baud rate. It seems to be a default or factory setting.

Any ideas that could solve the problem for me?

Thanks and regards