ESP32 pico uart problem 115200Bd and 921600Bd

[stefan.erni]

Hi Ben

I like to use M5 Atom lite, because it is very small board.

https://docs.m5stack.com/en/core/ATOM%20Lite
The connection to the pc is just working correctly if I add an IRQ in the program

And with 921600Bd it's received always wrong char even with IRQ.

Unfortunately, it doesn't work any better with the Atom S3 and Atom C3.
viewtopic.php?t=3223

working nice

2025-10-02_14-40-08.PNG (100.38 KiB) Viewed 49 times

Not OK without IRQ

2025-10-02_14-38-35.PNG (101.55 KiB) Viewed 49 times

post_uart_speed1.fcfx

(10.78 KiB) Downloaded 5 times

.
remark to 921600Bd:

With an ESP32 WROOM 32E and CH340C, the connection to the App Developer works perfectly with 92100Bd.

2025-10-02_15-01-22.PNG (479.87 KiB) Viewed 49 times

[stefan.erni]

Hi Ben

It looks like the Atom Lite has a special UART to USB bridge.
So don't look at it for too long. It works well with 115200Bd.
But with the C3 and S3, I can't connect to the App Developer with a component.
Most manufacturers no longer put a UART to USB bridge on the board.
I'm not planning to put one on my new board either.
Is there a possibility to connect it soon?