Brightness Control for Raspberry Pi MIPI-connected Display ☀️

A somewhat quick-and-dirty automatic/manual display brightness solution for Raspberry Pi. Works with VEML7700 ambient light sensors and displays that cooperate with sysfs.

Feature Overview

This project offers next brightness controls:

• Auto-Brightness Mode ./brightness --auto - adjusts based on ambient light
• Manual Control ./brightness <0-255> - for when you want to take charge
• Lux Monitoring ./brightness --showlux - troubleshooting or just because data is fun
• Systemd Preset Integration systemctl enable brightness-auto.service - runs reliably in the background

Hardware Requirements

• Raspberry Pi (tested on Pi 4)
• VEML7700 sensor (I2C-connected)
• Display with sysfs backlight control (tested on noname 7 inch 800x480 Aliexpress display with touch controls)

Software Requirements

• WiringPi library

Installation ⚡

1. Clone repository:

   git clone https://github.com/lenyaz/brightness.git
   cd brightness

2. Build project 🤞:

   make

Hint: you can install and enable systemd service using this line:

make install

3. Optional systemd setup (./add-systemd-service.sh):

   sudo cp brightness-auto.service /etc/systemd/system/
   sudo systemctl daemon-reload
   sudo systemctl enable brightness-auto.service
   sudo systemctl start brightness-auto.service

Usage

Manual Brightness Control

./brightness 128  # middle of 0-255 range
./brightness max  # maximum brightness possible (255)
./brightness min  # minimum brightness possible (1)
./brightness off  # display off (0)

Automatic Mode

./brightness --auto  # "Ambient Light: 20.22 lux, Setting brightness to: 6" 

Monitoring Mode

./brightness --showlux  # "Ambient Light: 20.00 lux"

TODO List 📝

• Optimization: Make it less memory and CPU hungry (types optimization etc.)
• Direct display brightness via GPIO: For speed (wiringpi?)
• Config file: Stop hardcoding like it's 1979
• Error handling: Because shit happens

Licensed under BSD 3-Clause License, Leanid "lenyaz" Veraksa, 2025