Home automation system developed on ESP32 microcontroller using freeRTOS with smart features. The entire system is controlled wirelessly via Bluetooth with a dedicated Android app.
- Showcased on Hackaday - Tiny Microcontroller Uses Real-Time Operating System
When we think of home automation we generally visualize switching on/off some buttons, temperature monitoring, etc.
It is not smart automation in true sense
- To achieve true home automation Real Time Operating System (RTOS) is integrated in the system which can perform multiple things simultaneously.
- The system is smart enough to automatically trigger actions based on certain events happening in real time.
- YouTube - youtu.be/aT6Lj6hBVUk
- Reddit - reddit.com/smart_home_automation
- Wireless control with Bluetooth
- Dedicated Android app
- Activity monitoring on OLED display and app
- Temperature sensing using DHT11 sensor
- Light intensity sensing using LDR
- Fan/Light control in 3 modes - manual, automatic (based on sensors) and off
- Person detection at door using ultrasonic sensor
- Touch detection on door with alarm using ESP32 inbuilt touch sensor
- Smoke detection with alarm using MQ2 sensor
- The entire system is custom made with wiring and placements planned according to requirements.
- It is developed to resemble a room in a house.
- ESP32 Microcontroller
- DHT11 Temperature and Humidity sensor
- LDR module
- MQ2 Gas/Smoke Sensor
- Ultrasonic Sensor
- OLED display
- Relay
- Buzzers
- Leds
- Bulb
- DC fan
Components can be assembled and connected as shown in the schematic.
To program the microcontroller Arduino IDE is used which is compatible with ESP32.
- Download and install the Arduino IDE
- Install the ESP32 Library at
File -> Preference -> Additional Boards Manager URLs:https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json - Then in the
Tools -> Board Manager-> search for ESP32 and install
Certain libraries are required for proper functioning of the microcontroller and interfaced components.
- Another important software required is freeRTOS which is responsible for real time functioning of components present in the system.
- ESP32 supports freeRTOS out of the box in Arduino IDE with its own flavour on the top of original for proper integration.
The Android app is developed on MIT App Inventor platform.
- Connect/Disconnect button is provided in the app to connect with the system via Bluetooth.
- There is no external bluetooth module used as the ESP32 microcontroller has one builtin.
- All the sensor activity and switch controls are monitored on OLED display that is interfaced using I2C communication protocol.
- The same is monitored on the android app.
- DHT11 digital sensor is used to sense temperature in the room and it is monitored on App/OLED.
- Light intensity in the room is sensed using a LDR (Light Dependent Resistor) module. This is used for automatic switching of bulb as explained later.
- For safety purpose, a smoke detection unit is implemented with MQ2 sensor which activates a buzzer and Led in presence of smoke.
- The buzzer turns off automatically once the smoke disappears.
A security system is implemented on the door using Ultrasonic and Touch sensors.
- If a person comes in the range of ultrasonic sensor mounted on the door, the App/OLED displays presence of the person and Led turns on to notify the same.
- If a person touches the door handle a buzzer is activated and App/OLED displays presence of touch along with an Led indicator.
- It can be deactivated by pressing the turn off button on app.
- Touch sensing is implemented using ESP32 inbuilt touch sensor.
The fan/bulb is operated in 3 modes using relays,
- Buttons on the App are used to manually switch on/off the bulb and fan.
- Automated switching of fan and light based on temperature monitored by DHT11 sensor and light intensity measured by LDR (Light Dependent Resistor) respectively is implemented.
- The fan automatically turns on when the temperature crosses threshold value of 33°C and turns off when it falls below the threshold.
- Based on the lighting conditions in the room sensed by LDR, the bulb turns on automatically when light intensity falls below certain threshold and vice versa.
- Everything can be switched off at once with one button on the app when leaving the room.
Parikshit Pagare
