Touch not working ESP32-S3 custom board

[ruben_vleuten]

Hi,

I've designed a custom board with the ESP32-S3 wroom module. I'm trying to do a very basic touch read on GPIO11. It's a very simple loop of reading the raw values of the pin for testing purposes. When I try the code on the Espressif ESP32-S3 dev board the code works fine.

Code: Select all

void loop()
{
  Serial.println(touchRead(11));  // get value using T0
  delay(1000);
}

When I try to run the code on my custom board it doesn't work however. I'm getting constantly the exact same readings on the ADC, not even minor fluctuations.

Code: Select all

10:02:37.840 -> 623194
10:02:38.840 -> 623194
10:02:39.848 -> 623194
10:02:40.824 -> 623194
10:02:41.829 -> 623194
10:02:42.836 -> 623194
10:02:43.838 -> 623194
10:02:44.847 -> 623194

It's a very simple design of a trace going from GPIO11 directly to the pad. I've looked into the hardware design guidelines but can't find anything specific why it shouldn't work.

What could be the reason why the ADC doesn't seem to work for touch signals on the ESP32-S3 on my custom board while it does work on the dev board?

[ESP_Bob]

Can you share your PCB overview here?

[ruben_vleuten]

Unfortunately I can not share the schematics since it's confidential work, but I contacted you through email

[silverchris]

Did you manage to resolve this? I am having a similar issue with my own custom board