Sketch won't upload to ESP32 (failed to connect)

Other Hardware LEDs and Multiplexing
1

Hello everyone,

I have a SparkFun ESP32 Thing Board, with which I want to control some Neopixel LED. I'm new to the whole ESP32/Arduino topic.

I followed this tutorial for my setup:
https://learn.sparkfun.com/tutorials/using-artnet-dmx-and-the-esp32-to-drive-pixels?_ga=2.21633981.725784081.1530282241-1247954538.1530282241

For uploading the sketch from Arduino IDE to the ESP32, I have to hold the physical "boot button 0" on the board, until the sketch starts uploading:

esptool.py v.2.3.1 Connecting..... -> pushing boot button -> transfer starts

Everything worked fine until yesterday. Now, the sketch won't upload, even if I hold down the "boot button".
(-> A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header).

Also the physical reset button doesn't seem to work anymore. (before: connection to WiFi gets refreshed by pushing the reset button). I dont get any output to the serial monitor.

The blue LED on the ESP32 at PIN 5 was blinking before, now it either constantly glows or doesn't glow at all.

What can I do to upload sketches to the ESP32? The ESP32 gets recognized from the USB port.

Thanks in advance!

2

Try a lower value for the transfer data rate.
If it doesn't work, try pushing the boot button, do not release it and push the reset button. Release reset then release boot.