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).

Filter by
Sorted by
Tagged with
0
votes
1answer
55 views

16 module relay board connection to RPi Zero W

I am using raspberry pi zero W for a home automation project. I am using 5V 16 channel relay board and using all the 16 relays as part of the project. I have not connected a separate 5V power supply ...
1
vote
0answers
23 views

SSR or Opto-Coupler relay only works if shorted

I have a SSR 4 channel relay and an Opto-Coupler one channel relay. Both where specified to work on 3.3V signals. I wrote a quick test program on my raspberrypi zero w and tried both relays with my ...
4
votes
1answer
300 views

Sainsmart 12V, 16 Channel relay module connected to RpiZW has unwanted triggering when booting

I'm trying to get the hydrosys4 open source irrigation control software to work with my 16 channel relay board and raspberry pi zero w. When the pi boots up the relay is triggered multiple times, ...
1
vote
1answer
23 views

Need script to make scheduled 8 channel relay outputs [closed]

This script fires my relays, but I don't know how to change duration and need it to fire daily to run pump and ozonator for an iso float tank. I'm currently only using GPIO 9 and 10 #!/usr/bin/python ...
1
vote
3answers
127 views

12v 4 channel relay pinout and explanation

I am kind of dipping my toe in this lake. Not a hardware/electronics person, more of a software guy (programmer). I am not able to easily find information about the 12V 4 Channel Relay (duinotech). I ...
0
votes
5answers
356 views

Raspberry Pi , RFID , Relay Module and Magnetic Door

I have used the code from github and in that code i am implementing the raspberry pi and the RFID and relay module with magnetic door unlock. Everything is working Okay , the RFID , the Relay module ...
0
votes
1answer
169 views

How to control raspberry pi 4 GPIO pins by running android application in the rpi and in mobile?

I am trying to build a project based on IoT. My goal is to trigger relays connected to GPIO pins in rpi4 by using an android application running in rpi4 itself which can be accessed with an official ...
0
votes
1answer
61 views

Use Pi to control power to usb-connected device

I have a digital microscope connected to my pi (usb) that you can use in a browser with a java web app that I have written. The microscope is also powered through the usb. There is no on or off switch,...
0
votes
2answers
54 views

Do I need additional protection when using a 5V relay module with the raspberry Pi?

Noob here, I have purchased a relay module (see pic below), and was wondering if I needed to add any other protection components to the Pi. Through my limited research, I found that using a diode, ...
0
votes
0answers
35 views

3.3v Relay switches on/off/on - off fails 2nd switch off

This 3.3v .relay, link to the the >>> Datasheet As the title mentions works fine until I try to switch it off the second time round, I see the red LED turning on (it looks a touch dim) ...
-1
votes
2answers
274 views

5V Relay only works if VCC is 3.3V

I am very new to all of this, so please excuse if this is a very basic question. I am trying to power a tiny water pump with my raspberry pi. For that I need the 3.3V or 5V output, because the GPIO ...
0
votes
2answers
60 views

RPi 3 B+, set defaults for GPIO pins on boot and shutdown

I am using Raspberry Pi 3 B+ with Linux raspberrypi 5.4.83-v7+ #1379 SMP Mon Dec 14 13:08:57 GMT 2020 armv7l GNU/Linux to control a set of relays. I set: gpio mode 7 output gpio mode 0 output gpio ...
1
vote
2answers
162 views

Using Relays to Power off then Cut power to Pi Zero

I have a raspberry pi zero that I am running off a battery for remote logging reasons. There is a low battery shut off module I have connected to the battery in case the battery gets below a certain ...
1
vote
2answers
110 views

How to detect if an external Relay is ON or OFF

I want to know the state of an external Relay connected to my Raspberry-Pi. Basically if there is current flow or not in A-B. A-B should be connected to R-Pi. I am not sure how to proceed even though ...
0
votes
2answers
36 views

How to drive two 3v relays safely from Raspberry PI?

I use PI 4 to power two 3v relays. One is controlling 5v dc, another 12v dc. And about once a minute I am switching each relay signal state to On/Off So each relay is connected to 3v pin, ground pin ...
0
votes
1answer
145 views

Using GPIO to control 5v relay module not working

so this is my first time trying to use a Raspberry pi and I wanted to automate a motor using a 5v relay module. I'm using a Raspberry Pi Zero W. I am using a 5v 2amp power supply to power the ...
1
vote
4answers
891 views

Using single 5V relay module (jqc-3ff-s-z) - Asking for help

I have a developer background missing the electronics background. I read some threads with great interest: Using single 5V relay (jqc-3ff-s-z) - safety advice required and 5V relay (jqc-3ff-s-z) I ...
0
votes
0answers
38 views

Protecting Raspberry Pi from EMI generated from VFD

I built a PCB to control a couple of Industrial contactors and an VFD. The GPIO are categorized, inputs and outputs. The output gpio are connected to the relay system.
0
votes
0answers
47 views

Raspberry PI and 8 module relay board

I have a raspberry pi 2 and an 8 module relay board (http://nettop.gr/index.php/en/hlektronika/relay/8-channel-5v-relay-module-with-light-coupling-5v.html). Between the relay board and the raspberry I ...
0
votes
1answer
45 views

DockerPi relay is wired backwards from others?

First off, apologies if I should have posted this elsewhere (such as under general electronics, etc.) I have two relays (JBTek, DockerPi relay hat) I have been experimenting with to control input ...
2
votes
1answer
824 views

Can you use a 5V Relay Module with the Pi?

Can you use a 5V Relay Module or similar with the Pi?
2
votes
0answers
69 views

Wiring 12V 5 pin relay (without a module/board) for usage with Raspberry Pi

I'm trying to setup an automated garden as a quarantine project for my mother and I can't really figure out how to properly wire a 12V 5-pin relay module as every tutorial online only shows the ones ...
1
vote
0answers
264 views

relay switch switches ON but never switches OFF [closed]

I connected my FL-3FF-S-Z two channel relay board to my Raspberry Pi 3, with gpio 0 and gpio 1 (numbers are from to $ gpio readall). Following some guide, as GPIO generates only 3.3v I have removed ...
0
votes
1answer
294 views

Relay Active HIGH

I am building an irrigation system, and to make it short, I need to decouple the electric-valve to the Raspberry. I am so using the following relay. It works fine, but it is active LOW, for my use ...
0
votes
1answer
307 views

5V Relay module working but LED not turning on - How to wire? [closed]

I'm trying to control a relay from Raspberry Pi that will switch an LED on/off. The relay is working (lightning up and clicking), but the LED doesn't turn on. Here is how I wired everything: VCC - 5V ...
0
votes
1answer
48 views

Raspberry Pi - Activate relay by phone [closed]

I'd like to set up a system to control a relay via land line. My goal is to somehow run a landline to the Raspberry Pi unit and have it trip a relay when the number is called and a DTMF sequence is ...
0
votes
1answer
31 views

using 2 pins to power the same relay

I have relay that requires 20mA to operate, which is a bit more than the pi can give from one pin. I as wondering if t was safe to connect 2 GPIO pins together to power the relay. I would use a diode ...
0
votes
2answers
311 views

How I can control an AC 220v with a relay and a Raspberry Pi 3B [closed]

I'm a newbie in this topics. I love electronics and I love the power of the boards like Raspberry Pi and I want to learn to use it by myself learning in internet, but I have a lot of lacks of ...
-1
votes
2answers
182 views

Problems with the rpi zero and relay [closed]

I Have a problem... (above the relay-coil Datasheet) I want to control a single relay with my pi zero, but it seems that it doesn't have enough power. the 3.3V pin of the rpi (measured to 3.19V) works ...
1
vote
2answers
659 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....
0
votes
3answers
457 views

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

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 ...
0
votes
0answers
36 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....
0
votes
0answers
167 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 ...
1
vote
0answers
203 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 ...
1
vote
1answer
180 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 ...
0
votes
1answer
75 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 ...
1
vote
0answers
560 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 ...
2
votes
4answers
104 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 ...
1
vote
1answer
163 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 ...
2
votes
1answer
187 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 ...
1
vote
2answers
296 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 ...
1
vote
2answers
322 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 ...
1
vote
1answer
204 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 ...
0
votes
0answers
515 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 ...
4
votes
4answers
254 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 ...
0
votes
0answers
30 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 ...
2
votes
2answers
1k 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 ...
0
votes
0answers
157 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 ...
2
votes
1answer
162 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 ...
1
vote
2answers
90 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 ...

1
2 3 4 5