ESP32 Relay Panel with MQTT, IR, PIR, NTP, and OTA for Home Assistant

Project Overview

This project demonstrates a fully-featured ESP32 relay panel with:

• 4 relays controllable via wall switches, IR remote, MQTT (Home Assistant).

• PIR motion sensor with adaptive cooldown and time-based relay activation:

  • Day (09:00–18:00): Relay1
  • Evening (18:00–23:00): Relay1 + Relay2
  • Night (23:00–09:00): Relay3
  • Relay4 always triggered by PIR if all relays are OFF

• WiFi LED indicator: solid when online, blinks on IR press

• MQTT Home Assistant Discovery for all 4 relays

• OTA updates via ArduinoOTA

• NTP synchronization with persistent time storage in Preferences/NVS

Hardware Requirements

• ESP32 DevKit (DOIT ESP32 DEVKIT V1 recommended)
• 4-channel relay module (active LOW)
• 4 wall switches (momentary, INPUT_PULLUP)
• PIR sensor
• IR receiver
• LED for WiFi status (optional)

Pin Mapping

Function	Pin
Relay 1	23
Relay 2	19
Relay 3	18
Relay 4	5
Switch 1	13
Switch 2	12
Switch 3	14
Switch 4	27
PIR	34
IR Receiver	35
WiFi LED	2

Software Dependencies

• Arduino IDE or PlatformIO

• Libraries:

  • WiFi.h
  • PubSubClient
  • IRremote (v4.x)
  • Preferences
  • ArduinoOTA
  • time.h (built-in)