ESP32 Forum

Hello,

I have a ESP32 8x Relay board (https://www.ebay.de/itm/146053681076) and an USB-TTL Adapter. The COM-Port is shown in the Device Manager. When I wanna write the sketch to the board Arduino IDE keeps complaining even the module seems to be correctly connected to the computer.

Globale Variablen verwenden 20080 Bytes (6%) des dynamischen Speichers, 307600 Bytes für lokale Variablen verbleiben. Das Maximum sind 327680 Bytes.
esptool.py v4.8.1
Serial port COM31
Connecting......................................

A fatal error occurred: Failed to connect to ESP32: No serial data received.
For troubleshooting steps visit: https://docs.espressif.com/projects/esp ... oting.html
Fehlgeschlagenes Hochladen: Hochladefehler: exit status 2

Is there a trick to get the ESP32 Module in "READ Mode"? Didn't fins any documentation about THIS product...

Best regards

Manuel

There are typically a couple transistors that allow the device to be automatically put into download mode, looks like this board doesn't have them. Hold down the IO0 button, then press reset (EN). That will manually put it into download mode.

Good mornin lbernstone,

thanks for your reply.
When and how long will I have to press the buttons?

Best regards
Manuel

Open serial monitor. Hold both buttons down. Release EN button. You should see a message on the monitor "Waiting for download"

I faced the same problem when using the ESP32 CAM. As soon as I see the dots, I press the RST button. Sometimes it solves the problem. Sometimes I need to restart my computer. You can try the same. Also check if you have selected the correct board and set your flash frequency to 40MHz. You can design a relay board like this by yourself.
https://www.pcbway.com/project/sharepro ... 88e48.html