Firmware for ESP 01 S devboard to control relays using MQTT. The code connects to a Wi-Fi network, subscribes to an MQTT topic, and toggles the relays based on received messages.
- Arduino IDE
- ESP 01 S devboard
- MQTT broker (e.g., mqtt.eclipseprojects.io)
- Connect your ESP 01 S devboard to your computer.
- Open the Arduino IDE and install the required libraries:
- Arduino Core for ESP8266 (should be installed by default for ESP8266 boards)
- ESP8266WiFi library
- PubSubClient library
- Replace the placeholders in the code with your Wi-Fi credentials (
ssidandpassword) and MQTT broker address (mqtt_broker) if needed. - Upload the sketch to your ESP 01 S devboard.
- Open the Serial Monitor to see the connection status and IP address.
The code connects the ESP8266 to the specified Wi-Fi network (connectify function) and MQTT broker (reconnect function). It subscribes to the "Relay" topic and waits for messages. The callback function processes incoming messages and controls the relays based on the message content (action function).
You can publish messages to the "Relay" topic with the following payloads to control the relays:
- "1on": Turn on Relay 1
- "1off": Turn off Relay 1
- "2on": Turn on Relay 2
- "2off": Turn off Relay 2
connectify(const char* network, const char* pass): Connects the device to the specified Wi-Fi network.action(String topic, String message): Modifies this function to take action when a specified message is published on a particular topic.callback(String topic, byte* message, unsigned int length): Receives the message information from the topic and calls theactionfunction.sublist(): Adds topics to listen to (in this case, it subscribes to the "Relay" topic).reconnect(): Reconnects the device to the MQTT broker if disconnected.setup(): Connects to Wi-Fi, the MQTT broker, and sets the callback function.loop(): Checks for connection status and reconnects if disconnected.
This project is licensed under the MIT License.
- Aman Shaikh
- Contact: [email protected]
- Firmware Version: 0.1