How to get GT911 interrupt working?

[senevoldsen]

Does anyone know how to use GT911 in interrupt mode?

The ESP32-2432S032C-I has a GT911 touch IC. According to the schematics the GPIO pin 21 connects to:

• GT911 INT pin via a "zero ohm" resistor.
• Connects to Pin 1 on the extended IO header (P3)
• GPIO 21 is shown to be between a 10k resistor to 3.3V, and Pin 2 on the "temperature and humidity interface " (CN1).

So my guess is that, that when none of the headers are connected, they are floating. But then it is still connected via "zero ohm" to GT911 INT pin, and also to 3.3V via. 10k R18 resistor. So I guess it is pulled-up if no signal drives it.

Reading the config register at 0x804D, which is named the "Module_Switch1" register, I get the value 0x05. Correlating with the datasheet , pg. 5: it tells me that means it the INT trigger mechanism is "falling edge".

However, the INT signal is constantly kept high. I can touch the display, and see with polling that data is ready, read it, and clear the 0x814E register, but I never get a falling edge. How do I get the falling edge trigger to work?

Here is the image showing the connection to the touch IC.

The pullup-resistor and CN1 header.

And the extend IO header.