Add CST816 touchscreen driver

[clydebarrow]

What does this implement/fix?

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

Related issue or feature (if applicable): fixes

Pull request in esphome-docs with documentation (if applicable): esphome/esphome-docs#3459

Test Environment

• ESP32
• ESP32 IDF
• ESP8266
• RP2040
• BK72xx
• RTL87xx

Example entry for config.yaml:

# Example config.yaml

Checklist:

• The code change is tested and works locally.
• Tests have been added to verify that the new code works (under tests/ folder).

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in esphome-docs.

[probot-esphome]

Hey there @esphome/core, mind taking a look at this pull request as it has been labeled with an integration (spi) you are listed as a code owner for? Thanks!
_{^{(message by CodeOwnersMention)}}

[nielsnl68]

Is it not better to break this PR into two parts one for the SPI and the other for the touchscreen driver?

[clydebarrow]

Oh, the spi stuff was not supposed to be in there - needed it for testing the board (could not do it as an external component), and thought I had avoided checking it in but obviously slipped up! Thanks for the heads-up.

[guillempages]

@clydebarrow I know you are on holiday (saw that on discord), and did not actually expect you to answer my comments so promptly. I just thought I'd write my thoughts in the PR.
Enjoy your holiday!

[dirkjankrijnders]

Hi, I'm working on a pull request for the cst820 #5641 which is very close to the cst816s. Maybe this can be one component?

[clydebarrow]

Hi, I'm working on a pull request for the cst820 #5641 which is very close to the cst816s. Maybe this can be one component?

Yes looks like one component would cover both. Will look at it more after Xmas.

[bearpawmaxim]

press all for corners and show the result?

Well, it is round, so touch sequence is the following (from 1 to 5):

[13:54:38][I][cal:140]: x=111, y=111, x_raw=112, y_raw=112
[13:54:39][I][cal:140]: x=138, y=218, x_raw=139, y_raw=219
[13:54:40][I][cal:140]: x=3, y=100, x_raw=4, y_raw=101
[13:54:42][I][cal:140]: x=152, y=5, x_raw=153, y_raw=6
[13:54:43][I][cal:140]: x=237, y=109, x_raw=238, y_raw=110

Update: looks like the touchscreen zero is located in the upper right corner.

P.S.: no rotation is applied to the display

[clydebarrow]

Touch now works, but binary sensor doesn't

Does that display have a binary sensor? Where would it be? IIRC the 816 implements it by reporting a touch outside the screen boundary.

[alantreadway]

Hi - I found this PR whilst trying to get a board with the designation ESP32-2432S024 up and working with ESPHome.

I followed the thread to try out this PR, and was hitting Chip type: Unknown - using the lambda provided by bearpawmaxim to log the chip id, I'm seeing: 0xB7 - not sure if this works (will try to fork and tweak now to confirm).

[clydebarrow]

to log the chip id, I'm seeing: 0xB7

I have added that as CST820. Try it and see.

[bearpawmaxim]

Does that display have a binary sensor?

Ah, I now understand what the binary sensor means.. I mistakenly thought that binary sensor should trigger when you touch the screen area and that touch lies within the binary's sensor coordinates.
Now it is clear for me.

@clydebarrow one more question.
Because my "chinese miracle" have touchscreen and display zero coordinates mismatch (it is rotated 90° clockwise).. Can't you provide the rotation ability?

[clydebarrow]

Can't you provide the rotation ability?

https://deploy-preview-3487--esphome.netlify.app/components/touchscreen/

To rotate 90 or 270 you will need swap_xy and one of the mirror settings.

[alantreadway]

to log the chip id, I'm seeing: 0xB7

I have added that as CST820. Try it and see.

Thanks - I'm seeing Chip type: CST816S in the logs now, but that is the last message I see (tried with two different boards to rule out hardware failure) - not sure if I'm configuring things correctly, so it's unclear what is going on.

I don't really have time to dig into this further now, but when I do I can raise a PR if further changes are needed?

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 53.50%. Comparing base (4d8b5ed) to head (1e5d616).
Report is 74 commits behind head on dev.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev    #5941      +/-   ##
==========================================
- Coverage   53.70%   53.50%   -0.21%     
==========================================
  Files          50       50              
  Lines        9408     9515     +107     
  Branches     1654     1683      +29     
==========================================
+ Hits         5053     5091      +38     
- Misses       4056     4117      +61     
- Partials      299      307       +8     

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[pixelwave]

I have the ESP32-2432S024C with CST820 touch controller as well and trying to get the touch functionality working. I got the screen displaying stuff with this code:

color:
  - id: my_red
    red: 100%
    green: 3%
    blue: 5%

spi:
 clk_pin: GPIO14
 mosi_pin: GPIO13
 miso_pin: GPIO12

display:
  - platform: ili9xxx
    model: TFT 2.4
    cs_pin: GPIO15
    dc_pin: GPIO2
    rotation: 90
    id: tft_ha
    lambda: |-
      it.fill(my_red);

output:
  - platform: ledc
    pin: 27
    id: gpio_27_backlight_pwm

light:
  - platform: monochromatic
    output: gpio_27_backlight_pwm
    name: "Display Backlight"
    id: back_light
    restore_mode: ALWAYS_ON

How do I get the touch now working / what files do I have to include in my ESPHome build? Sorry I am still learning ESPHome ... quite new to the syntax. If somebody could give me support that would be awesome.