ESP Light

ESP32 firmware for a WS2812 light/strip with a built-in factory access point, web-based setup, MQTT, and Home Assistant auto-discovery.

Features

• Factory mode with Wi-Fi AP and web UI
• Runtime control over MQTT
• Home Assistant MQTT discovery
• Persistent Wi-Fi, MQTT, and light settings in NVS

WS2812 Wiring

• ESP32 GPIO25 -> WS2812 DIN
• ESP32 GND -> WS2812 GND
• External 5V PSU -> WS2812 5V
• Keep ESP32 and LED strip grounds common
• For stable operation, a level shifter and a 330-470 Ohm series resistor on the data line are recommended

Do not power longer LED strips from the ESP32 board directly.

Prerequisites

• PlatformIO CLI
• bun
• python3
• USB serial access to the ESP32 board

Build and Flash

The default serial port is hardcoded in Makefile. In most cases, override it from the command line:

make build
make BOARD_TTY=/dev/ttyUSB0 flash
make BOARD_TTY=/dev/ttyUSB0 flash-factory
make BOARD_TTY=/dev/ttyUSB0 monitor

Useful targets:

• make build builds both firmware images and merges them into .pio/build/esp_light.bin
• make flash builds and flashes the full image at 0x0
• make flash-factory flashes only the factory firmware
• make build-app builds only the application firmware
• make build-factory builds only the factory firmware and web UI

First Setup

1. Flash the device with make flash.
2. On first boot, the device starts in factory mode if Wi-Fi is not configured.
3. Connect to the AP named MyrtIO Светильник XXYY.
4. Open http://192.168.4.1/ or the IP printed in the serial log.
5. Fill in the Wi-Fi SSID and password, MQTT host/port/credentials, and the LED strip settings: led_count, skip_leds, color_order, brightness_min, brightness_max, color_correction.
6. Save the configuration and boot the app firmware.

Press the button on GPIO0 to switch between factory mode and application mode.

Wi-Fi And MQTT

• Wi-Fi credentials are stored in NVS and used on every boot
• MQTT default port is 1883
• MQTT client ID and topic namespace are generated as myrtio_light_XXYY
• Home Assistant discovery is published automatically after MQTT connection

Main MQTT topics:

• State: myrtio_light_XXYY/light
• Command: myrtio_light_XXYY/light/set
• Availability: myrtio_light_XXYY/availability
• Discovery: homeassistant/light/myrtio_light_XXYY_light/config

License

MIT