My 3v3 relay is not powered on

#1

Hello, i have a 3v3 relay board like it : https://fr.aliexpress.com/item/1-pi-ces-1-canal-3-V-Module-relais-3-3-V-faible-niveau-de-prise/32855219447.html?spm=a2g0s.9042311.0.0.19b16c37DvD1Fp

I have connected the vcc to the 3v3 of the raspberry gpio, the gnd to the gnd of the gpio and the In1 to the gpio 24.

The led of the relay turn on a little bit when the In1 is not connected and not at all when it is connected.

I have measured 3v3 between 3v3 and gnd when the cable is not connected to the relay and 0v when he is connected.

What can i do to solve it?

#2

That has what to do with OctoPrint exactly? :face_with_raised_eyebrow:

#3

I want to use it with the PSU control plugin to power on and off my printer

#4

Where are you placing a voltmeter when this happens? If you are seeing 0v, does the Raspberry Pi die (turn off)?

#5

on the cable that connect the relay board to the raspberry pi.

No he didn't

#6

You are seeing 0v across VCC and GND when you have it hooked up? Or you are seeing 0v on the blue screw terminals on the far side?

I assume your 3v is fine and the problem is triggering the GPIO. For that you need to put your meter between GND and pin 24, then turn pin 24 high and low:

gpio mode 24 out
gpio write 24 high
# ensure meter shows 3v here
gpio write 24 low
# ensure meter shows 0v here

Make sure that works before looking at the blue screw terminals. In fact, you don't even need the relay to ensure this.

These are assuming you are using physical pin 24; if you are using BCM pin 24, do this:

gpio -g mode 24 out
gpio -g write 24 high
# ensure meter shows 3v here
gpio -g write 24 low
# ensure meter shows 0v here

If this doesn't work, you'll need to describe/illustrate it better or hope that a french speaker can help you in your native language.

#7

I have try and there is nothing. I'm not sure, it is right if i tape the commands in the ssh terminal?

#8

The problem is solved, i'm stupid, I reversed the direction of the raspberry