KY-019 5V Relais

int relay = 10; // Declares the pin to which the relay is connected
 
int delayTime = 1; // Value in seconds how long to wait between the switchovers
 
void setup ()
{
  pinMode (relay, OUTPUT); // The pin is declared as output
}
 
// The program simulates a blinker - it switches the relay in predefined 
// time (delayTime) between the two states (or output terminals).
void loop ()
{
  digitalWrite (relay, HIGH); // "NO" is now shorted;
  delay (delayTime * 1000);
  digitalWrite (relay, LOW); // "NC" is now shorted;
  delay (delayTime * 1000);
}

This module contains a 5V relay that is used for switching higher currents. The relay switches the applied voltage through as soon as 5V is applied to the voltage input of the switch. This allows it to be controlled in order to safely switch larger electrical loads on and off.

The relay module has two output terminals:

NC (normally closed): This output is closed by default without electrical switching. This means that the current flows through this path as long as the relay is not activated. NO (normally open): This output is open by default without electrical switching. This means that the current only flows through this path when the relay is activated. With these two output terminals, you can control whether the circuit should be closed or open in the idle state and change the current supply accordingly by applying 5V to the voltage input of the relay. This module is ideal for applications where it is necessary to safely switch higher loads or devices, such as in home automation systems, industrial control systems or other projects that require reliable power switching.

Working with voltages of more than 30 V and especially with mains voltage (230 V) can lead to physical injury and can even be fatal. We advise that work with higher voltages should only be carried out with the appropriate technical expertise.

Technical Data
Voltage range (AC)	0 V - 240 V AC at 10 A
Voltage range (DC)	0 V - 28 V DC at 10 A
Required switching current	ca. 15 - 20 mA
Relay type	Changeover switch
Dimensions	53 x 18 x 20 mm

Pin assignment

Raspberry Pi	Sensor
GPIO 24 [Pin 18]	Signal
5 V [Pin 2]	+V
GND [Pin 6]	GND

Code example

The program simulates a flashing light - it switches the relay between the two states (or output terminals) in predefined time (delayTime).

# Required modules are imported and set up
import RPi.GPIO as GPIO
import time
 
GPIO.setmode(GPIO.BCM)
# here the pause (in seconds) between switching is declared
delayTime = 1
 
# Here the input pin is declared to which the sensor is connected. Additionally the PullUP resistor at the input is activated
RELAY_PIN = 24
GPIO.setup(RELAIS_PIN, GPIO.OUT)
GPIO.output(RELAIS_PIN, False)
 
print ("Sensor test [press CTRL+C to exit test]")
 
 
# main program loop
try:
    While True:
        GPIO.output(RELAIS_PIN, True) # NO is shorted now
        time.sleep(delayTime)
        GPIO.output(RELAIS_PIN, False) # NC is shorted now
        time.sleep(delayTime)
 
# clean up after the program is finished
except KeyboardInterrupt:
    GPIO.cleanup()

Sample program download

KY019-RPi.zip

To start with the command:

sudo python3 KY019-RPi.py

	
		input.onButtonPressed(Button.A, function () {
		    pins.digitalWritePin(DigitalPin.P1, 1)
		})
		input.onButtonPressed(Button.B, function () {
		    pins.digitalWritePin(DigitalPin.P1, 0)
		})
	

# Load libraries
from machine import Pin
from utime import sleep

# Initialization of GPIO18 as output
device = Pin(18, Pin.OUT, value=0)

# Switch on relay
print('On')
device.on()

# Wait 3 seconds
print('.')
sleep(1)
print('.')
sleep(1)
print('.')
sleep(1)

# Switch off relay
print('Off')
device.off()

# You should hear some sort of click when the relay switches.