Sometimes an ESP32 board refuses to connect to the Arduino IDE for uploading a sketch when using Windows. When that happens, there are two things you can do.
- Hold down the “Boot” button on the ESP32 board while uploading the sketch. OR
- Place a ~.2 uf capacitor between the RST and GND pins on the Arduino (suggested by Adafruit)
One or the other of these suggestions usually works. The first one works like a charm for me using Windows 7.
Thank you James! Yes, in some cases the boards or the Arduino IDE is not automatically going to flashing/uploading mode and you have to fold down the BOOT button. I’ll be adding those instructions to the course in the next update.
Thanks for this solution. On my NodeMCU 32S dev board, after clicking “Upload”, I wait until the compilation completes, and then when the console says “Connecting …”, I press the “Boot” button for a few seconds and then release. Works for me.
Exactly Lance! Thanks for the suggestion and I’ve added your procedure to the troubleshooting guide (issue #4): https://rntlab.com/esp32-troubleshooting-guide/
I even recommend holding the “BOOT” button before pressing the “Upload” button just to be sure that it forces the ESP32 into flashing mode.