An app that allows you to control the rear LED ring on a Unihertz Jelly Star on LineageOS
Also adds a quick settings tile for turning the LED ring on/off
Requires root access
Changing the brightness value writes 1-255 to /sys/bus/platform/devices/lampbelt_leds/driver/lampbelt_leds_duty
Writing a 0 to this turns off the lights
The quick tile toggles between 255 and 0 to lampbelt_leds_duty
The "mode 2" button writes a 2 to /sys/bus/platform/devices/lampbelt_leds/driver/lampbelt_leds_mode which causes the lights to flash in a pattern
Values 0-6 are valid for lampbelt_leds_mode but 2 is the best one
Tested on a Unihertz Jelly Star running AndyYan's LineageOS GSI - lineage-21.0-20260324-UNOFFICIAL-arm64_bvN
This app does nothing special, You can do what this app does with a root ADB shell or Termux
As this app writes direct values to the LED brightness controls this may cause overheating/battery drain if the LEDs are left on
The rear LED ring will automatically turn off when the screen turns off
App is vibe coded