Waveshare ESP32-S3 Touch LCD 7 - backlight pinon GPIO 16

[schnoog]

Description

The display hasn't the backlight wired to any usable GPIO by default.
It's required to solder a connection between a test pad and a GPIO.
GPIO6 which is used in the available user_setting requires soldering the connection not only to the test pad but also a pad/leg of the ESP32.
GPIO16 on the other hand is available over a JST connector and therefore only requires one - relatively easy - solder connection to use the delivered cable to get it working

It's a copy of waveshare-esp32-s3-touch-lcd-7.ini with -D TFT_BCKL=6 changed to -D TFT_BCKL=16
and renamed the to env waveshare-esp32-s3-touch-lcd-7-gpio16
Additionally added the env to be build workflow.

Type of Change

• New device / board support
• Bug fix
• New feature
• Refactoring / core change
• Documentation
• Other

Scope

This PR is focused on:
Waveshare ESP32-S3-Touch-LCD-7

Checklist

• My changes only affect one clear goal
• I have tested the changes on real hardware (if applicable) (1)
• The code builds cleanly for at least one existing board (1)
• I have added/updated documentation where needed
• No unrelated files were changed

(1) https://github.com/schnoog/openHASP/actions/runs/32584170030/artifacts/9478672664

[fvanroie]

Hi, thanks for this additional info. Just to be clear: the Backlight Pin is just a default suggestion that can be changed in the WebUI > Dusplay Settings:

So we don't normally create a new firmware just for the backlight pin.
Can you check if GPIO16 is available in the default waveshare-esp32-s3-touch-lcd-7 build?

It could be that the pin is "reserved" and not listed...

[schnoog]

Hi, thanks for your response.
GPIO16 is available in the dropdown, but selecting it and saving it didn't have any effect.
I didn't dive into the projects code base, but changing the ini, compiling it, uploding it and afterwards setting the BL GPIO to 16 again did finally work.

Does a pre-configured pin block later assignments or did I just mess it up?

[fvanroie]

selecting it and saving it didn't have any effect

The most common reason is probably that you "reset" or "power cycled" the board via RST or disconnecting power.
If so, please try selecting pin 16, click Save Settings and make sure to Reboot the plate using the red Restart button in the WebUI.

The config is saved when you soft reboot, but not when you just unplug/reset the board... I think that could explain it?
When the pin is visible and you restart the device via the Restart webUI, it should work!

TLDR:

• WebUI → Save Settings → red Restart button → configuration is persisted/applied.
• Physical reset via RST or simply unplugging/power-cycling may not persist the newly selected setting.