TechnoLED

Firmware for ESP32-based LED controller with WiFi, MQTT, and OTA update support. Designed for remote lighting control via MQTT messages, handling both static and dynamic LED patterns at ITIC Paris school.

Overview

TechnoLED is an embedded system project built for the ESP32 platform. It provides the following capabilities:

• WiFi connectivity and automatic reconnection handling
• MQTT communication for LED state updates and remote control
• OTA (Over-The-Air) firmware updates via HTTP
• NeoPixel LED strip management (e.g., WS2812-based LEDs)
• Basic diagnostics over serial output

Features

• WiFi

  • Connects using provided SSID and key
  • Displays IP address and connection status on serial monitor

• MQTT

  • Publishes device state to /devices
  • Subscribes to a LED control topic (e.g., /room/11/leds)
  • Handles control payloads for LED behavior

• OTA Update Server

  • Accessible via: http://<device_ip>/update
  • Allows firmware upload through browser or curl -F 'image=@firmware.bin' http://<device_ip>/update

• LED Control

  • #RRGGBB → Set all LEDs to specified color
  • * → Activate rainbow pattern
  • I → Turn all LEDs on (white)
  • O → Turn all LEDs off

Configuration

Modify the following constants before compiling:

#define LED_PIN   IO4 // <- TO FILL
#define LED_COUNT 300 // <- TO FILL

const char *hostname = "esp32_room_XX";
const char *wifiSsid = "<your_wifi_ssid>";
const char *wifiKey  = "<your_wifi_password>";
const char *mqttHost = "<mqtt_broker_ip>";
const char *mqttUser = "<mqtt_username>";
const char *mqttPass = "<mqtt_password>";

Topics can be customized:

const char *ledsTopic = "/room/XX/leds";
const char *stateTopic = "/devices";

Hardware

• Board: ESP32-ETH01
• LEDs: WS2812B pixel strip
• Power adapter: AC/DC 230v to 5v, 80W (for 22m strip)
• Pinout: Only 1 pin is necessary for the data pin
• Wires, breadboards, …

Build and Flash

1. Open project in Arduino IDE
2. Download and Select the ESP32 board type (WT32-ETH01)
3. Adjust configuration values
4. Compile and upload firmware via USB
5. Once connected, note IP address from serial output
6. Optionally, use the OTA endpoint for future updates

Dependencies

Install these Arduino libraries:

• WiFi.h
• WebServer.h
• HTTPUpdateServer.h
• MQTT.h
• Adafruit_NeoPixel.h