GPIO 25 and 26 issue with external touch IC
Posted: Tue Aug 31, 2021 11:51 pm
Hello, I am working on custom hardware with ESP32 wrover-e. I have a TTP224 touch module with 4 touch outputs connected to ESP32 module's GPIOs 33, 32, 25 and 26. The touch is IC is on a separate PCB connected to mainboard by headers. Touch IC is configured as sending HIGH (3.3v) to GPIO's on touch with led's as indicators.
With GPIO 33 and 32, the touch registers fine along with the led indications. With 25 and 26 though, the touch acts finicky and basically does not work, the led's are sometimes flickering with no touch. As soon as isolate the 25 and 26 trace from the touch IC, the touch works normally. I have also checked for any other errors with the hardware on the touch IC side, traces on the mainboard etc. The thing is, even when I disable any power to the ESP32, the touch buttons still misbehave. Only isolating the touch IC traces from GPIO alleviate the issue.
My question is, are GPIO's 25 and 26 are said to be used for DAC, do you have to disable the DAC on these pins for proper operation as GPIO or should I try and changing GPIOs? I'm using I2S and not the internal DAC, if that matters.
With GPIO 33 and 32, the touch registers fine along with the led indications. With 25 and 26 though, the touch acts finicky and basically does not work, the led's are sometimes flickering with no touch. As soon as isolate the 25 and 26 trace from the touch IC, the touch works normally. I have also checked for any other errors with the hardware on the touch IC side, traces on the mainboard etc. The thing is, even when I disable any power to the ESP32, the touch buttons still misbehave. Only isolating the touch IC traces from GPIO alleviate the issue.
My question is, are GPIO's 25 and 26 are said to be used for DAC, do you have to disable the DAC on these pins for proper operation as GPIO or should I try and changing GPIOs? I'm using I2S and not the internal DAC, if that matters.
- Pinout
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