Ah!

I have enabled I2C, although I am no longer using it. I will switch to Pin/GPIO 17 as suggested.

If it works with the digital control pin connected to GND, then there are at least two possibilities for malfunction. 1) Your control wire is connected to the wrong RPi pin or 2) Your code isn't working as you expect. edit: Have you tried using a different GPIO pin? Thanks Tim, Got it working with ...

Try connecting the digital control pin to GND on the RPi. Do you get a response from the relay board? Hi Tim, Appreciate your reply. Good thinking-- connecting it to ground works! It functions as might be expected-- both LED toggles, and the noise of the switch activating/deactivating can be heard ...

Hi,

Making the suggested changes and running commands like

import RPI.GPIO as GPIO

GPIO.setmode(GPIO.BCM)
GPIO.setup(2, GPIO.OUT)
GPIO.output(2, GPIO.LOW)
GPIO.output(2, GPIO.HIGH)

does nothing. No clicking, no LEDs, nothing.

Please note that these commands do nothing even in my original wiring.

You'll see there's a jumper installed, connecting Vcc to JDVcc One of those supplies is for the relay; the other is for the opto-isolator input The relay requires 5v, but the GPIO cannot supply 5v to switch the opto off, so you need to remove the jumper and supply 3v3 to the other supply. Hi Burnga...

its been like 12 hours now...

Hi, I have tried to follow this guide
https://www.youtube.com/watch?v=oaf_zQcrg7g

and I have wired it as shown below



however it doesn't light up and doesn't seem to work at all.

Any tips?