Relay board with high level/ low level trigger selection

gistfile1.txt

Most relay boards are 'ACTIVE LOW' which means: 0 or LOW (0V) = Relay ON, 1 or HIGH (3V3) = Relay OFF.

Some relay board have high and low level trigger mode selection. We can use jumper pin to select the mode the mode.

If low level level trigger mode is selected then Relay on will occure for control signal 0 / false / ground

If high level trigger mode is selected then Relay on will occure for control signal 1 / true / 3V3/ Vcc or Vdd

Ref. https://robu.in/product/songle-single-channel-5v-30a-relay-module-power-failure-relay/
Above 5V 30A relay module has trigger mode selection. I have tested it with Low level trigger mode only.

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)
GPIO.setup(05, GPIO.OUT)
GPIO.output(05, GPIO.HIGH)


GPIO.output(05, GPIO.LOW)
print "Relay on for 5 sec"
time.sleep(5)
GPIO.output(05, GPIO.HIGH)
print "Relay off for 5 sec"
time.sleep(5);

# Reset GPIO settings
GPIO.cleanup()