Questions tagged [relay]

Electrical device which, when energised by a small electrical current (low-power, control circuit), safely switches a larger electrical current (controlled circuit).

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119 views

How to turn off relay when RPi shuts down

I have connected a relay to BCM 14 and by setting its output to HIGH I can turn it on, making a 220V bulb to turn on. I use for that the following python instructions: GPIO.setmode(GPIO.BCM) GPIO....
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92 views

How can Rpi python control a 5V relay module, opto-isolated, with a JDVcc jumper?

Just starting to explore python, Raspberry and a relay. I want to control my 2-channel relay with a button. This is my test code: import RPi.GPIO as GPIO import time import requests from datetime ...
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30 views

Relay is behaving differently from tutorial

Given: Raspberry Pi3 Sunfounder 2 channel relay plugged into 3.3v plugged into ground plugged into pin 18 import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BCM) GPIO.setup(18, GPIO.OUT) GPIO....
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31 views

GPIO Power off on shutdown with retropie

i asked this question before but i have added a diagram to explain it more clearly. I am building a retropie arcade machine with a raspberry pi. I have added a shutdown / startup button to shutdown ...
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38 views

How to cut power to gpio pins on shutdown

I am working on a project where i am using a pi running retropie to make a homemade arcade machine. i have wired and coded a startup/shutdown button. i would like to set up the pi n such a way i can ...
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1answer
51 views

Running pump & servo - Relay needed?

simulate this circuit – Schematic created using CircuitLab So I am working on a project that will require both a servo motor plus a small water pump. Both run on 3.7 -6v and I am going to use ...
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1answer
33 views

no output from 8 channel relay when i run the python script below

# import GPIO and datetime import RPi.GPIO as GPIO import datetime # set GPIO numbering mode and define output pins GPIO.setmode(GPIO.BOARD) GPIO.setwarnings(False) GPIO.setup(37,GPIO.OUT) #Relay 1 ...
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82 views

RPi.GPIO + single channel relay + solenoid lock

I'm working on my first python/hardware project and I want to create a simple (or at least I thought it was simple) cabinet lock, which will lock/unlock when certain RFID tags are approached to the ...
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4answers
80 views

Why is my relay switching on automatically when I start my program?

I'm building a little automated hydroponics system using a raspberry pi zero, a 5 volt relay, a pump and a soil moisture sensor from adafruit. So far everything is working, I can pull the pin to high ...
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1answer
62 views

Process to select and stack a relay HAT and a touch-display HAT

The goal is to design thermostat system via stacking Raspberry pi HATs: Raspberry pi (3B+ or 4) 4-channel relay TFT Touch Display It would be preferable that community experience point out any ...
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1answer
151 views

Relay does not turn off

I am trying to control a 4-Relay module with my Raspberry Pi 4. I tried to do that by writing this script: import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BOARD) relais_1 = 8 relais_2 = 10 ...
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95 views

Use HC-SR04 Distance Sensor and Relay to trigger the Water Pump - Need help with triggering the pump

I am trying to trigger/stop a water pump with the use of a 4-channel relay and a UC-SR04 distance sensor. I tried with some codes but I think I am missing something because although there was no error ...
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2answers
145 views

Multi-threading python function using list and dictionary of GPIO pins cannot activate a relay problem

At the first part of the code(Initializing relays) the GPIO output works as expected, but at the second part it doesn't works, I have break my head for the last four hours trying to find out what is ...
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1answer
70 views

How to make a system that uses a mobile sim and that acts on a relay by ringing the sim

I want to create a system that has an internet connection via a mobile sim and allows owners of enabled telephone numbers to switch a relay by ringing the device sim. The system must be able to ...
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My Pi is annoying my security alarm system

I'm a bit of a Pi addict - we've got six Pis around our house doing various things. My latest project was to add a little bit of smart control to our dumb MHRV (Heat Recovery) system. I've got a Pi ...
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212 views

Rpi3 Home Assistant To Read Signals at GPIO Pins Problem

I'm really new to Raspberry Pi, so please forgive me if this is a noobish question. I have a very simple setup: Raspberry Pi 3 running Home Assistant with a switch connected to GPIO12 and 3.3v. The ...
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4answers
151 views

gpio turning on/off relay, seems backwards

I have a Raspberry Pi 3b and wired to a 4 port relay I got from Amazon: https://www.amazon.com/JBtek-Channel-Module-Arduino-Raspberry/dp/B00KTEN3TM/ Everything is working, but it seems backwards to ...
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25 views

Powering solenoid from batterypack

Im trying to power my 6V solenoid that is connected to my 8 channel 5V relay using my 8 x AA batterypack. The pi is being powered through an adapter and the relay from the VCC to 5V pi. When the LED ...
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2answers
217 views

how do I automatically power off the raspberry pi and cut power every night and then power it back on each day?

Background I'm a student working on research project to develop a remote wireless sensor network of data loggers. Each data logger (aka node) is going to be retrofitted to a bird feeder that reads ...
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71 views

using Pi Zero W GPIO relay control

I am trying to control my relay with Raspberry GPIO. Using the terminal to write to gpio5 (Physical 18, BCM 24) works: gpio mode 5 out gpio write 5 1 Trying to do the same in my c++ code doesn't ...
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1answer
120 views

12V Solenoid with Relay doesnt trigger

So I am using 8 AA 1.5V batteries that is wired to my 12V 16 channel relay which is wired to my Rpi. I want to be able to control 16 solenoids and use the relay as a switch for the solenoids. As far ...
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40 views

GPIO.OUT() Not working for 16 channel relay

So I am using a 16 channel relay that is connected to my Pi (https://www.amazon.com/dp/B0057OC66U/). I made a small program to turn all the relay LEDs on and then turn them off one by one with a 1 ...
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2answers
65 views

Relay modules: Can I switch AC in one and DC in another?

I would like to control both 120VAC and 24VDC from my RPi 3B+. To make this easy, I'm looking at one of the various 3ch or 4ch relay modules for an RPi 3B+, like this or this. I'm familiar with using ...
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110 views

External power supply to a relay controlled by a Raspberry Pi

I am a beginner to relays and Raspberry Pi so please pardon me if my question sounds naive. I am trying to control 4 DC motors using relays and raspberry pi. I have decided to use an external supply ...
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1answer
126 views

I think I fried my Raspberry Pi, but I'm not sure

I was making connections from my Raspberry Pi to a relay module. While I was running some sample code, I noticed that after I had terminated the program I was still getting a high CPU usage (around 60%...
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2k views

Rpi GPIO Controlling 5V Relay Problem

I am working on a project that requires a camera analyzing some images and activating the appropriate GPIOs to control a relay board. I currently have a touchscreen display, a Raspberry Pi Cam ...
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2answers
814 views

How can Rpi UART control an IR Remote HDMI switcher?

I've been reading about how to use the GPIO to toggle a button on a thing I've taken apart. It's like this: Amazon I watched a video of a guy using an opto-coupler, what are the basics here? I'm ...
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3answers
63 views

Voltage dropped significantly on GPIO 4 with a relay coil

I have a Raspberry PI 3 B+, and when I activate the GPIO 4 as output and checking agains a multimeter I get its 3.3V as expected. If I connect the GPIO4 to one end of a coil (http://www....
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685 views

Driving 12V/24v Relay from raspberry pi

I am trying to drive the 12V/24V relay using Rasberry pi 3. I have got schematic from one of the forum.I have question related to below schmatic. 1) The ckt build to drive 5V relay . How can use ...
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95 views

Is 5V out on the Pi Zero W unregulated?

I want to power a 5V relay breakout board from a Pi Zero W. I believe the 5V pads are "raw" and a "pass through" voltage? Is this correct?
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4answers
2k views

Wiring a 4 channel relay - is this possible?

After watching many videos and reading, I think I now know how to wire a 4 channel relay to control 4 12V DC Solenoids with my PI. The Solenoids are wired in parallel. Please see picture 1. However,...
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1answer
217 views

Is a RC snubber required when using the pi with a relay?

I am hoping to use raspberry pi to switch on and off a heating lamp and an aquarium pump via a relay switch. Both devices are plugged into 120V AC normally. The relay tutorials online seem to be ...
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3answers
148 views

Can a relay be on for 16 hours continuously?

A part of my engineering project involves a L.E.D tubelight staying on for 16 hours continuously. I am connecting the light to a relay module. Is it ok, if the relay stays on for so long? I mean, is ...
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110 views

Issues with Sequent Microsystems 8 relay board

I'm using the Raspberry Pi 3 Model B V1.2, and the Sequent Microsystems 8 Relay Board 2.0. The manual tells you to install this software from github. I installed this and was able to control the ...
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2answers
1k views

Rpi cannot activate 5V Relay with optical isolator and JD-Vcc jumper

Devices I am using are: 1) Songle 2 channel relay module - https://www.electronicscomp.com/2-channel-5v-relay-module-with-optocoupler?gclid=...
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1answer
179 views

Rasberry pi 4 channel relay switch off after 10 seconds

import RPi.GPIO as GPIO import time def mist(): GPIO.setmode(GPIO.BCM) # setup and switing on relay GPIO.setup(4, GPIO.OUT, initial=GPIO.LOW) # sleep for 30 second ...
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594 views

How can I wire a Raspberry Pi to an 8-relay board in a tidy professional manner?

I want to connect a Raspberry Pi to an 8-relay board, such as this one. Together with ground and power this amounts to ten wires. One option to connect the two is by using female to female jumper ...
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134 views

How does the relay work?

I have a SRD-05VDC-SL-C relay (that is, a 5V controlled relay). Inputs, on relay, are VCC,IN and GND. Now, I wanted to try if it is working. So I plugged RPi's 5V to VCC, and GND to GND. Relay's ...
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1answer
69 views

How to toggle a 1 Channel Relay 5V

So. I have a 1 Channel 5V relay from a starter kit and I cant turn it on or off. I saw a bunch of tutorials but in every one the labels on the relay are such as VCC, GND and so on. My relay its ...
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1answer
46 views

What is the highest amount of relays Pi 3 can handle?

I'm looking to do something interesting with 16-20 laptop and computer fans. I was wondering if this was possible to just connect them to a large battery and then use a trigger to control some power ...
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98 views

Connecting a PIR and Relay Module to a Raspberry Pi causing 2 Minute False Alarms

I am building a small home automation system, and one node has a PIR to detect motion, and a Relay Module to control a 240v light with a Raspberry PI 3. The PIR is connected to 5v, and has a ...
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1answer
92 views

Wiring that won't damage my pi [closed]

A while ago, I decided to wire up a Raspberry Pi (Zero W) to a few peripherals, but it stopped working shortly afterward (not entirely, but I think it was undervolting the power rails). I had ...
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98 views

Raspberry Pi's Ethernet cable port suddenly stopped working after connecting 4-channel Relay board

I am having trouble with my Raspberry Pi's Ethernet and USB ports. I was using Ethernet port usually for my experiments with pi. But I tried to connect 4-channel relay board to my pi. According to my ...
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1answer
90 views

Help needed with GPIO and a remote controlled gate relay switch

I am very confused and hoping someone can point me in the right direction. What I would like to achieve is converting an external relay switch (from a normal everyday gate receiver) into a signal ...
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1answer
319 views

External 12v power supply to relay

I have a 12v 8 channel relay https://www.modmypi.com/raspberry-pi/relays-and-home-automation-1032/relay-boards-1033/8-channel-12v-relay-module which I want to connect to my RPi3 so I need an external ...
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370 views

Relay Bluetooth keyboard out as a USB keyboard

I have a bluetooth keyboard that's originally connected to my desktop PC. The problem is that I can't use it in BIOS or to select different boot options at grub because the bluetooth drivers aren't ...
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3answers
132 views

4 relay board weird behavior

i'm new to this platform, I hope I'm doing everything right. I bought a 4 relay board some time ago to use it with my pi. When I tested it with the pi, it worked well. After a while I decided to use ...
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1answer
1k views

5v relay led comes on and off but relay doesn't switch (no clicking)

channel SunFounder 5V 8 Channel Relay, which stopped working and I'm not sure if because something I did: The first time I connected to my pi everything worked, I powered the board from 5v pin of the ...
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1answer
33 views

Will connecting a photoresistor module affect a mains relay in anyway?

I have a raspberry pi connected to a mains relay, which is connected to an ac lamp and outlet onto a breadboard. I want to add a photoresistor module to the raspberry pi/breadboard but I'm afraid it ...
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2answers
131 views

Small pulses - DHT11 relay triger

I'd like to trigger my relay to turn on my lamp when the humidity level measured is greater than 85. Here's the code I've been using. import Adafruit_DHT import RPi.GPIO as GPIO import time sensor = ...