Custom ESP32 S3 board never runs code

[jenschr]

Hi all,
I'm making my 8th ESP32-S3 based board and I was completely stumped by a problem I've never seen. The ESP-S3-WROOM-1 based board programs, but it's not running any code and it's not outputting anything on Serial.

After a lot of troubleshooting, I hooked up a serial dongle to the Serial output and I could see that the board goes straight into download mode like this:

ESP-ROM:esp32s3-20210327
Build:Mar 27 2021
rst:0x1 (POWERON),boot:0x0 (DOWNLOAD(USB/UART0))
waiting for download

It never runs any code. I searched and searched but could not find anyone with a similar problem, but wouldn't you know - it was my own fault and I'll share it here in case it can help others. I had swapped the resistor and capacitor on the boot button ( ). The resistor tied the boot button to GND, putting it into eternal BOOT mode.

Hope this helps others as it took me close to two hours until I found it

[ESP_Sprite]

Note that you may want to remove the capacitor on GPIO0 entirely. Having a capacitor between GPIO0 and ground means GPIO0 will be low for a moment on power-up, meaning as soon as you apply power the ESP32C3 will boot up in download mode initially.

[jenschr]

Thanks! That's good advice that I'll use!

[and.abramchuk]

In my case, this issue been solved only when I made two improvements:
1. Remove the capacitor on GPIO0 entirely
2. Attach external pullup resistor (5k1) on GPIO0