How to Use WiFi Single Relay Module ESP DC5-80V Wireless Controller Relay Module Board: Examples, Pinouts, and Specs

The WiFi Single Relay Module ESP DC5-80V Wireless Controller Relay Module Board (Manufacturer: JESSINIE, Part ID: ESP-12F) is a versatile wireless relay module designed for remote control of electrical devices via WiFi. It integrates seamlessly with ESP8266/ESP32 microcontrollers, making it an ideal choice for IoT and home automation projects. This module supports a wide DC voltage range of 5-80V, providing flexibility for various applications.

• Home automation (e.g., controlling lights, fans, or appliances remotely)
• Industrial automation and control systems
• IoT projects requiring wireless relay control
• Smart agriculture systems (e.g., irrigation control)
• Remote switching of low-power or high-power devices

Below are the key technical details and pin configuration for the module:

1. Power the Module: Connect the VCC pin to a DC power source (5-80V) and the GND pin to ground.
2. Connect the Load:
   • For devices that should be powered when the relay is active, connect the load between the NO (Normally Open) and COM (Common) terminals.
   • For devices that should be powered when the relay is inactive, connect the load between the NC (Normally Closed) and COM terminals.
3. Control the Relay: Connect the IN pin to a GPIO pin of an ESP8266/ESP32 microcontroller. When the GPIO pin outputs a HIGH signal (3.3V), the relay will activate, switching the load.
4. Program the Microcontroller: Use the provided code example to control the relay via WiFi.

• Ensure the load current and voltage do not exceed the relay's maximum ratings (10A, 250V AC / 30V DC).
• Use proper insulation and safety precautions when working with high-voltage loads.
• Avoid rapid switching of the relay to prevent wear and tear on the mechanical components.
• Use a flyback diode across inductive loads (e.g., motors) to protect the relay from voltage spikes.

Below is an example code to control the relay module using an ESP8266 microcontroller:

#include <ESP8266WiFi.h>

// Replace with your network credentials
const char* ssid = "Your_SSID";
const char* password = "Your_PASSWORD";

// Define the GPIO pin connected to the relay module
#define RELAY_PIN D1

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(115200);

  // Set the relay pin as an output
  pinMode(RELAY_PIN, OUTPUT);

  // Start with the relay off
  digitalWrite(RELAY_PIN, LOW);

  // Connect to WiFi
  Serial.print("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected!");
}

void loop() {
  // Example: Turn the relay on for 5 seconds, then off for 5 seconds
  Serial.println("Relay ON");
  digitalWrite(RELAY_PIN, HIGH); // Activate the relay
  delay(5000);                  // Wait for 5 seconds

  Serial.println("Relay OFF");
  digitalWrite(RELAY_PIN, LOW); // Deactivate the relay
  delay(5000);                  // Wait for 5 seconds
}

1. Relay Not Activating:

   • Ensure the IN pin is receiving a 3.3V HIGH signal from the microcontroller.
   • Verify that the VCC and GND pins are properly connected to a power source.

2. WiFi Connection Fails:

   • Double-check the SSID and password in the code.
   • Ensure the ESP8266 is within range of the WiFi router.

3. Load Not Switching:

   • Confirm that the load is connected to the correct relay terminals (NO/NC and COM).
   • Check that the load's voltage and current are within the relay's rated limits.

4. Module Overheating:

   • Ensure the load does not exceed the relay's maximum current rating (10A).
   • Provide adequate ventilation around the module.

Q1: Can this module be used with a 5V microcontroller like Arduino UNO?
A1: Yes, but you will need a level shifter or a transistor circuit to step down the 5V control signal to 3.3V for the IN pin.

Q2: Is this module compatible with MQTT or other IoT protocols?
A2: Yes, when paired with an ESP8266/ESP32, you can use libraries like PubSubClient to implement MQTT or other IoT protocols.

Q3: Can I control the relay over the internet?
A3: Yes, by configuring the ESP8266/ESP32 for internet connectivity, you can control the relay remotely via a web server or cloud platform.

Q4: What happens if the power supply exceeds 80V?
A4: Exceeding the maximum voltage rating can damage the module. Always use a regulated power supply within the specified range (5-80V).