I FOUND THE SOLUTION!!!
After diving into deep of operating system I figured out a possible solution which worked for me:

1. I had a usbserial.kext laying in /Library/Extensions/ and I figured out that it was also a WCH driver
2. I deleted usbserial.kext and restarted the Mac again => no success
3. I deleted CH34xVCPControlDriver.kext and CH34xVCPDriver.kext in /Library/Extensions/ and restarted again
4. I installed another driver: FTDIUSBSerialDextInstaller_1_4_7 and had to confirm SIP integrity
5. In system preferences -> security I had to enable access for the FTDI driver and saw another process pending named something with Quinheng
6. As I remembered that Quinheng has something to do with WCH I ticked this process too and restarted
7. I installed CH34xVCPDriver.pkg V1.7 again and restarted => no success
8. I plugged in a CH340G device and suddenly a /dev/cu.wchusbserialXXX port appears in my Arduino IDE and is working with my CH9102 device
9. Plugging out CH340G device continues /dev/cu.wchusbserialXXX working

Hope that this solution will work for other people too!

I just ordered 5 pcs of new M5Stamp C3 and would like to know what ESP32 board I have to choose to program in Arduino IDE. I downloaded newest version of ESP32 boards but M5Stamp C3 isn't included.

@felmue said in M5Stamp C3 programming examples:

Hello @ajb2k3

What worked for me on macOS Big Sur 11.5.2 is using the ESP32C3 built-in USB via GPIO18 and GPIO19.

What also worked for me on macOS Big Sur 11.5.2 was downloading and installing this driver CH9102_VCP_SER_MacOS from here. After a reboot and plugging in M5StampC3 via USB this port show up /dev/cu.wchusbserial... (in addition to /dev/cu.usbmodem... which did not work).

Thanks
Felix

Hello Felix
read here for a possible solution.

I FOUND THE SOLUTION!!!
After diving into deep of operating system I figured out a possible solution which worked for me:

1. I had a usbserial.kext laying in /Library/Extensions/ and I figured out that it was also a WCH driver
2. I deleted usbserial.kext and restarted the Mac again => no success
3. I deleted CH34xVCPControlDriver.kext and CH34xVCPDriver.kext in /Library/Extensions/ and restarted again
4. I installed another driver: FTDIUSBSerialDextInstaller_1_4_7 and had to confirm SIP integrity
5. In system preferences -> security I had to enable access for the FTDI driver and saw another process pending named something with Quinheng
6. As I remembered that Quinheng has something to do with WCH I ticked this process too and restarted
7. I installed CH34xVCPDriver.pkg V1.7 again and restarted => no success
8. I plugged in a CH340G device and suddenly a /dev/cu.wchusbserialXXX port appears in my Arduino IDE and is working with my CH9102 device
9. Plugging out CH340G device continues /dev/cu.wchusbserialXXX working

Hope that this solution will work for other people too!

@ajb2k3 said in cant flash latest m5 stamp c3:

or try another TTL USB to UART adapter

It's the built in adapter of M5Stamp C3!

@felmue said in cant flash latest m5 stamp c3:

What worked for me on macOS Big Sur 11.5.2 however is using the ESP32C3 built-in USB via GPIO18 and GPIO19.

I urgently need a working driver for m5stamp c3 for MacOS 10.15.7 Catalina. I tried to get it work via GPIO18 and GPIO19 but don't know how because there is no driver for that on my system. Using USB-C ist throwing the known error because of the wrong or incomplete driver. Even downloading and installing the suggested driver didn't solve the problem.

@felmue said in cant flash latest m5 stamp c3:

Hello @HaSch

well, disabling downloading the stub doesn't help anyway - so my idea is moot. I've just setup a machine with macOS Big Sur 11.5.2 and with or w/o downloading the stub the download process ends in an timeout error.

What worked for me on macOS Big Sur 11.5.2 however is using the ESP32C3 built-in USB via GPIO18 and GPIO19.

Thanks
Felix

It really seems to be an issue with USB serial driver. I also tried to download and install the CH9102_VCP_SER_MacOS driver from here without success. Trying to install to my MacOS 10.15.7 Catalina ends up with an error:

安装提示
sysex didFailWithError The operation couldn’t be completed. (OSSystemExtensionErrorDomain error 9.)

@felmue said in cant flash latest m5 stamp c3:

I was wondering, in your case it fails while 'Uploading stub' which as I understand is not necessarily needed. In menuconfig there is an option Serial flasher config - Disable download stub which by default is unchecked. Maybe try to disable the downloading of the stub and see if that gets you any further.

I'm sorry, I'm using Arduino IDE and there is no menuconfig. But I have "USB CDC On Boot". Should it be enable or disable? I'm on a Mac with MacOS 10.15.7 Catalina.

@felmue said in cant flash latest m5 stamp c3:

I've just tried flashing my M5StampC3 through its built-in USB. Worked like a charm.

I have no chance to flash any file:

esptool.py v3.1
Serial port /dev/cu.usbmodem53220362951
Connecting....
Chip is unknown ESP32-C3 (revision 3)
Features: Wi-Fi
Crystal is 40MHz
MAC: 34:b4:72:12:9b:ac
Uploading stub...

A fatal error occurred: Failed to write to target RAM (result was 01070000)
A fatal error occurred: Failed to write to target RAM (result was 01070000)

Is there a usb driver missing? How to get and install?

BR,
Hans

@daniyyel said in cant flash latest m5 stamp c3:

indeed, using different ttl-to-usb I managed to flash it. Had to manually
enter load mode (grounding pin 9) and now all is ok.
thanks

What ttl2usb driver did you use?

@felmue said in M5Stamp C3 and Arduino IDE:

Hello @HaSch

The error message looks familiar - see this thread.

Thanks
Felix

I looked at this thread but it didn't work for me. Grounding Pin 9 and trying to flash ends with the same result.
How can I use another TTL2USB port? I only have the one provided using the board.

@felmue Error message:

esptool.py v3.1
Serial port /dev/cu.usbmodem53220362951
Connecting....
Chip is unknown ESP32-C3 (revision 3)
Features: Wi-Fi
Crystal is 40MHz
MAC: xx:xx:xx:xx:xx:xx
Uploading stub...

A fatal error occurred: Failed to write to target RAM (result was 01070000)
A fatal error occurred: Failed to write to target RAM (result was 01070000)