[cst816][pca9554] is an invalid option for [interrupt_pin]

lboue commented 1 week ago

The problem

Hello.

I'm looking for the right ESPHome syntax to configure a touchscreen connected via a PCA9554 I/O expander. This is the YAML config:

touchscreen:
  platform: cst816
  id: cst816_touchscreen
  interrupt_pin:
      pca9554: pca9554a_device
      number: 3

And I am getting this error: [pca9554] is an invalid option for [interrupt_pin]. Please check the indentation.

I didn't find it here:

Regards

Which version of ESPHome has the issue?

2024.4.2

What type of installation are you using?

Home Assistant Add-on

Which version of Home Assistant has the issue?

2024.5.1

What platform are you using?

ESP32-IDF

Board

Adafruit Qualia ESP32-S3

Component causing the issue

touchscreen

Example YAML snippet

# PCA9554 I/O Expander
# https://esphome.io/components/pca9554.html
pca9554:
  - id: pca9554a_device
    address: 0x3F

# 2.1" 480x480 round display use CST826 touchscreen with I2C Address at 0x15
touchscreen:
  platform: cst816
  id: cst816_touchscreen
  interrupt_pin:
      pca9554: pca9554a_device
      number: 3

Anything in the logs that might be useful for us?

No response

Additional information

Testing with this screen: Round RGB 666 TTL TFT Display - 2.1" 480x480 - Capacitive Touch - TL021WVC02CT-B1323

randybb commented 1 week ago

Interrupts via expanders are not supported. Expanders have their own interrupt pin, but since it is not connected and not supported in esphome it cannot detect interrupt so this cannot work.

lboue commented 1 week ago

@randybb Technically, it works with this board and this screen. In fact, it works when programmed with Arduino or CircuitPython. This is a limitation of ESPHome and not of the PCA9554 chip.

randybb commented 1 week ago

If your program is polling GPIOs constantly, then yes, but once you start using interrupts, then such approach is not going to work.

ssieb commented 1 week ago

There's no benefit to using the interrupt pin on an expander. If you have to query the expander to get the pin state, then you might as well just query the touch screen directly.

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