I haven´t played with my Wemos for some time. When I tried to flash a new sketch with the Ardunio IDE the upload of the sketch failed with espcomm_open failed and espcomm_upload_mem failed errors. The D1 was visible as USB device and the serial console output was some cryptic text no matter what baud rate I chose.
First I thought the problem was that I was running the IDE on Windows 10 or that the D1 was not supported by my version of the IDE.
As workaround I flashed the sketch directly via the hardware serial port as suggested here
. This worked but using a USB to TTL converter was somewhat disappointing when you normally just flash the ESP via USB.
To find the final solution was simple but it took me some time to find out 😉
I simply reinstalled the USB-Drivers for the CH340 chip that does sthe USB to TTL conversion for the D1 mini!
- Download the driver here.
- If the driver is already installed – uninstall it
- Reinstall it and see if you can upload your sketches (Default upload speed is 115200)!
I am still not sure what was the initial cause for the problems. Maybe some driver for one of my other Arduino clones messed something up…