Guide to flash ESP8266 in CJMCU-3212.
For the guide we are going to use https://github.com/spacehuhn/wifi_ducky
1: Put the CJMCU as ESP programmer
The first thing to do is put the arduino as a programmer, so, in Arduino put
Tools-> Board-> Arduino Leonardo
Tools-> Port -> (the corresponding port)
And upload this sketch
2: Upload the sketch on the ESP
download the 4m binary from here
Now, the Magic (or the solution that worked for me):
Disconnect the CJMCU.
Bridge the two metal circles on the top right before connect the CJMCU to the USB. (image)
Once connected, run in esptool:
python esptool.py --trace --baud 150200 --port /dev/ttyACM0 write_flash 0x00000 ../esp8266_wifi_duck.ino.generic.bin --flash_size 4MB --flash_mode dio --flash_freq 40m
Now, disconnect the bridge.
3: Upload the wifi ducky sketch
Ready, wifi_ducky is working =)
I hope this solution works for you, any problem ask me