dmesg
[ 9702.953920] usb 1-10: USB disconnect, device number 60
[ 9702.954306] usb 1-10: failed to send control message: -19
[ 9702.954582] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0
[ 9702.954635] ch341 1-10:1.0: device disconnected
[ 9703.600791] usb 1-10: new full-speed USB device number 61 using xhci_hcd
[ 9703.749887] usb 1-10: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.54
[ 9703.749892] usb 1-10: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[ 9703.749895] usb 1-10: Product: USB2.0-Serial
[ 9703.751945] ch341 1-10:1.0: ch341-uart converter detected
[ 9703.752414] usb 1-10: ch341-uart converter now attached to ttyUSB0
But the second invocation with platformio device monitor uses the correct baud.
Can you do a miniterm.py /dev/ttyUSB0 74880 then press the reset button? This should display the bootloader messages. If nothing comes up, something is wrong with the chip-enable or reset lines. What is your exact hardware setup?
No i didn’t disconnect this bridge after flashing, because it worked before without disconnect the bridge. And in Arduino IDE it works also without disconnect the bridge.
But after i disconnect the bridge and reset the chip it works.