Embedded Heater Control System An ESP32-based heater automation project that uses a DS18B20 temperature sensor and a relay to maintain a target temperature. The system operates via a state machine (Idle, Heating, Stabilizing, Target Reached, Overheat) with overheat protection and visual warning via a blinking LED.
🚀 Features
- Accurate Temperature Monitoring — DS18B20 digital sensor (±0.5°C)
- Automatic Heater Control — via relay module
- Safety Override — overheat cut‑off at ≥75 °C
- Visual Alert — blinking LED in overheat condition
- Clean State Machine Logic — for predictable, stable operation
- UART Serial Logging — for debugging and monitoring
- Optional BLE Module — for mobile monitoring/control (code included but commented)
🛠 Hardware Requirements
- ESP32 Dev Board
- DS18B20 Temperature Sensor (+4.7 kΩ pull‑up resistor)
- Relay Module (to control heater)
- Red LED (+220 Ω resistor)
- Breadboard, jumper wires, power supply
🔌 Pin Mapping Component----------Pin GPIO DS18B20-DQ GPIO 4 Relay--IN GPIO 26 LED + GPIO 2 GND/3.3V Common
📊 System States . IDLE – Heater OFF, waiting for temperature drop . HEATING – Heater ON until near target temp . STABILIZING – Maintaining temperature within tolerance . TARGET REACHED – Heater OFF, stable temp maintained . OVERHEAT – Heater OFF + blinking LED warning
🛠 How It Works
- DS18B20 continuously reads temperature.
- ESP32 compares readings with target and tolerance values.
- Relay turns the heater ON/OFF depending on the state.
- Safety cutoff triggers at ≥75 °C, LED blinks every 500 ms.
📂 Repository Contents sketch.ino — Main firmware code for ESP32 diagram.json — Wokwi circuit simulation wiring file HEATER-CONTROL-SYSTEM.pdf — Full design documentation README.md — This file
🔗 Project Links Wokwi Simulation: https://wokwi.com/projects/439089545074845697