1-CH 12V Relay Board

1-CH 12V Relay Board Documentation

The 1-CH 12V Relay Board is a widely used IoT component that allows you to control high-voltage devices using a microcontroller or a single-board computer. This relay board features one SPDT (Single Pole Double Throw) relay, which can be used to switch on/off devices that require up to 12V and 10A of current.

Pinout:

The relay board has the following pinout:

VCC: Power supply for the relay board ( typically 5V or 3.3V)
 GND: Ground pin
 IN: Input pin to control the relay ( Logic level: 0V for OFF, 5V for ON)
 NO (Normally Open): Output pin connected to the normally open contact of the relay
 COM (Common): Output pin connected to the common contact of the relay
 NC (Normally Closed): Output pin connected to the normally closed contact of the relay

Operating Principle:

The relay board works by applying a voltage to the input pin (IN) to control the relay. When the input pin is high (5V), the relay is energized, and the normally open (NO) contact is connected to the common (COM) contact. When the input pin is low (0V), the relay is de-energized, and the normally closed (NC) contact is connected to the common (COM) contact.

Code Examples:

### Example 1: Controlling a DC Fan using Arduino

In this example, we will use an Arduino Uno board to control a DC fan using the 1-CH 12V Relay Board.

Hardware:

Arduino Uno board
 1-CH 12V Relay Board
 DC fan (12V, 1A)
 Jumper wires

Code:
```c
const int relayPin = 2;  // choose a digital pin on the Arduino board

void setup() {
  pinMode(relayPin, OUTPUT); // set the relay pin as an output
}

void loop() {
  digitalWrite(relayPin, HIGH); // turn the relay ON
  delay(5000); // wait for 5 seconds
  digitalWrite(relayPin, LOW);  // turn the relay OFF
  delay(5000); // wait for 5 seconds
}
```
How it works:

In this example, we connect the IN pin of the relay board to digital pin 2 of the Arduino Uno board. We set the relay pin as an output in the `setup()` function. In the `loop()` function, we toggle the relay ON and OFF every 5 seconds using the `digitalWrite()` function.

### Example 2: Controlling a LED Strip using Raspberry Pi

In this example, we will use a Raspberry Pi board to control a LED strip using the 1-CH 12V Relay Board.

Hardware:

Raspberry Pi board
 1-CH 12V Relay Board
 LED strip (12V, 1A)
 Jumper wires

Code:
```python
import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)  # use Broadcom pin numbering
relay_pin = 17  # choose a GPIO pin on the Raspberry Pi board

GPIO.setup(relay_pin, GPIO.OUT)

try:
    while True:
        GPIO.output(relay_pin, GPIO.HIGH)  # turn the relay ON
        time.sleep(5)  # wait for 5 seconds
        GPIO.output(relay_pin, GPIO.LOW)  # turn the relay OFF
        time.sleep(5)  # wait for 5 seconds
except KeyboardInterrupt:
    GPIO.cleanup()
```
How it works:

In this example, we connect the IN pin of the relay board to GPIO pin 17 of the Raspberry Pi board. We set up the relay pin as an output using the `GPIO.setup()` function. In the main loop, we toggle the relay ON and OFF every 5 seconds using the `GPIO.output()` function.

Note: Make sure to use a suitable power supply for the relay board and the connected device. Also, ensure that the relay board is properly connected to the microcontroller or single-board computer before uploading the code.