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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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1answer
13 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
24 views

Send data from raspberry pi to another raspberry pi

I'm currently working on a project where I have 2 RPIs both with multiple sensors e.g. dht22, sw-420, photoelectric IR optocoupler and they are connected to cloudMQTT. What I need is that the data ...
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1answer
32 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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0answers
13 views

KNACRO 4-Channel DC 5V Relay Module - What is the 'com' that is on the GPIO side?

KNACRO 4-Channel DC 5V Relay Module 30A DC 30V/AC 250V connected to a Raspberry PI 3 B+. 3 channels will work but 1 won't. I'm assuming is a 3.3 vs 5v issue. It doesn't matter which 3 I use they all ...
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0answers
27 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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2answers
31 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
36 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
21 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
34 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 = ...
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0answers
20 views

Several relays power consumption on RPi Zero

I'm making a element, where my RPi zero turns on/off 4 relays (REES52 Optocoupler 4 Channel 5V Relay Module). I want my circuit to work constantly for as long as possible (ideally for several years) ...
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2answers
99 views

Relay stays on when toggling GPIO pin between LOW / HIGH

I've got a small 5v relay board ("Ontengfei" JQC-3FF-S-Z) connected to my Raspberry Pi 3 B+. When I set the GPIO pin mode to OUTPUT, the relay turns on. When I toggle the GPIO pin between HIGH / LOW, ...
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1answer
41 views

Pi 3 and SainSmart 8 channel SSR - Not able to turn on all 8 relays

Pi 3 and SainSmart 8 channel SSR - Not able to turn on all 8 relays Environment: Raspberry Pi 3 OS: Raspian Language: Python3 and Java/Pi4J Control: SainSmart 8 channel Solid State Relay Issue: ...
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1answer
47 views

Node-Red does not turn off the relay

In Node-Red, whenever I put a single status type for reading the GPIO status or GPIO in/out in the flow, it turns on the relay. I cannot turn of it by injecting 0 value as string. When I delete all ...
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1answer
41 views

Trying to make a timer script with Python but I can't seem to get it working

So I'm trying to make a timer script that will run one relay (on/off) at a given time everyday, then the other seven to perform a function over time or (once started) to be interrupted by a switch ...
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2answers
48 views

Detecting electricity via a relay board

First of all: I'm still learning about electronics, so please be patient with me and help me when I use wrong vocabulary. I am sure this question has already been asked but I cannot quite find what I ...
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0answers
115 views

How to use DS3231 RTC module on Android Things?

I use Raspberry pi 3 model B on Android Things. my situation https://stackoverflow.com/questions/51887326/when-boot-device-if-can-not-connect-to-the-network-how-to-set-current-time-on so, I bought ...
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1answer
42 views

Sending RPi data over network [duplicate]

I have 3 Pi's on a network that need to scan one GPIO on each, and if that GPIO changes, broadcast to the other two so they can trigger another GPIO as an output to trip a local relay. HELP??
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2answers
73 views

why GPIO.LOW is used to turn the switch on?

I am learning raspberry pi and somewhere i found the tutorial of turning the bulb on when clap is heard and off the bulb when clapped again. The following code was written for this to work #!/usr/bin/...
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3answers
282 views

Raspberry Pi Relay Protection [closed]

I took a picture of my mock setup to give a better idea of what I'm working with. Basically, I'm will be using relays connected to my Raspberry Pi that I intend to use to control a series of lights (...
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1answer
62 views

Protecting Raspberry Pi from Relays

I took a picture of my mock setup to give a better idea of what I'm working with. Basically, I'm will be using relays connected to my Raspberry Pi that I intend to use to control a series of lights (...
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0answers
37 views

Relay for controlling backlight of touchscreen not reacting after a while

I connected my rpi3 to a 10" touchscreen. I connected the backlight of the touchscreen to a relay which I'm controlling via the GPIO pins. This is working fine for the first couple of minutes. But ...
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1answer
98 views

Raspberry Pi Zero W - freezes after switching a relay connected to an AC motor [closed]

I'm working on a home IOT using Rpi to run script that controls opening/ closing window's shade ( switching its electric motor up or down ). 1) Code is very simple and working fine - switching gpio "...
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0answers
40 views

Sync 5 Raspberry Pi3 B+

Hi I'm new to programming and Raspberry Pi. What I am looking for is what platform I need to play in sync a unique video-loop for each RPi (off a USB). I have installed Raspian. Each is connected to ...
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1answer
130 views

Using a Relay to command solenoids

Power to solenoids through relay Hi, I'm newbie and I'm trying to drive solenoids through Pi. I'm not sure about the connection between Pi and Relay and also from Power source to relay and solenoids. ...
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1answer
117 views

Triggering Peristaltic Pump with GPIO

This seems really basic but I've tried googling many different ways and can't seem to find the right answer, so I'm sorry for what may be a tired question, but: How can I mimic a footswitch press ...
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3answers
743 views

Powering RPI 3 and using relay from same source

I want to build something of a smart home device such as a smart switch /outlet for example that controls something like a light. However, I don't know what the wiring should be Like, if it's possible....
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3answers
232 views

Turn on and off 5V to 12V Relay

I want to use my Raspberry Pi to turn on and off a 12V current for a certain amount of time. I've read a lot on this forum and I've understood that the 5V GPIO Pin is... Not GPIO, meaning that I ...
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2answers
245 views

Check relay module state

I found a few good answers and guides about how to control a relay module from the pi, however, I want to find a way to check its state/status from the pi, is there a way to determine if the relay is ...
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2answers
356 views

Open/Close Sliding Gate Using Raspberry Pi and Python

This is my first Raspberry Pi project. I’m a bit of a noob at the Pi, Python and other types of programming languages, as well as circuits and such. I’m trying to open my sliding gate to the entrance ...
2
votes
3answers
469 views

GPIO relay signal cross turns to all relays staying on after Darlington added

I have 4 Sunfounder 2 channel relays 7 of which that I'm using to control some things on my aquarium. I suspect that I may have wired them up wrong somehow though. The behavior I'm seeing is as ...
2
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3answers
235 views

Monitor problem when turning on relays

i'm new to this part of the forum and the raspberry. Hope my way of questioning is appropiate and that you can get a picture of what i'm talking about. Otherwise please be merciful. I have a little ...
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2answers
121 views

Failed to initialize PiFace Relay+

When trying to initialize the Piface Relay+ with: pfr = pifacerelayplus.PiFaceRelayPlus(pifacerelayplus.RELAY) I get these errors: Traceback (most recent call last): File "/home/pi/Documents/...
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2answers
138 views

Raspberry PI Relay power motor [closed]

Does anyone happen to have a similar example for a python code when pressing a button a relay is turned on which is powering a motor to open a gate for 5 seconds and then closes by giving a signal to ...
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2answers
178 views

Raspberry pi 12v relay

I have bought this relay: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F262722739443 In the '1 channel 12v relay' variety I am going to be using it to power ...
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2answers
734 views

GPIO pin LOW not LOW enough (aka how to ZERO the tension on a low pin?)

This question was asked before here, but there was no answer 1 year ago. I'm facing the same issue: I'm switching the same 5V relay (SONGLE SRD-05VDC-SL-C) using a GPIO on HIGH and this works, but ...
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1answer
449 views

No audible click from 5V relay when using Raspberry Pi Zero W [closed]

I am trying to use a 5v relay (SunFounder Relay Module for Arduino and Raspberry Pi 5V DC Trigger by HIGHLO (HIGH Trigger) to be exact) and I am running into some issues. I have a python script ...
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0answers
227 views

How can a simple NPN step up from 3.3 to 5, without 5V in picture?

I've come across this circuit to common pi problem of stepping up 3.3 GPIO to 5V, so it could drive a relay module (Link here). I've one doubt, most circuits online also have a 5V input in the circuit,...
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1answer
283 views

Controlling High voltage devices with Raspberry Pi

Can I control high voltage (here 5V) to power a led lamp and a fan(both operating at 5v) from Raspberry Pi GPIO only using a transistor . Or should I isolate both the circuits using a relay or octo-...
0
votes
1answer
891 views

Sending RF codes to 433 learning relay

I have this RF learning relay https://www.youtube.com/watch?v=QuFzDcIiDxQ this is how relay learns codes. However I don't have remote and want to control it using Pi. I've tried sending various ...
2
votes
1answer
308 views

Relay switches but no power

I am trying to connect my Raspberry Pi 3 to a relay and power a small pump with that. The relay I use: 8-Relay. I can use the water pump with 3V to 12V and I want to connect a 5V external power ...
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3answers
1k views

Simple Relay Control Pi Zero W

I have a Pi Zero W and a Velleman VMA406. Wired like this Pi Pin 2 (5v) - Relay "+" Pi Pin 6 (GND) - Relay "-" Pi Pin 11 (GPIO 17) - Relay "S" When I run the following script I see a faint flicker ...
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0answers
50 views

Open a “dumb” Tv(or any device) together with pi

am a newbie in this segment and lacking knowledge in many parts so excuse me if i dont show the proper understanding in the following text.So,what i wanted to do originaly is open my TV together with ...
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1answer
644 views

3.3v to GPIO input using relay

I'm exploring various ways to detect higher voltage using the Pi and have come up with a circuit where the 5v would energize the coil of a relay which would switch 3.3v from the Pi's internal 3.3v ...
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0answers
72 views

Issue with Vixen Seq - Pi3 - FPP- relay board

I'm trying to wire my Pi 3B to the relay (octocoupler). I'm wiring the 5V (pin 2 and 4 on the Pi) to the relay, also the grounds. I'm using the following GPIOs from the Pi (Pin numbers): 7(GPIO4)-11(...
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0answers
94 views

Real time alteration of delay times between multiple lights turning on/off using button inputs

I'm having some trouble changing how long lights are on/off for within a loop. I'm using one of the standard 8 relay boards to do this. What I currently have is 2 buttons (momentary push buttons) that ...
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4answers
1k views

“Blinking” relay by toggling pins between input and output

Edit for searches: This question is about using a 5v relay with Raspberry Pi GPIO pins that outputs 3.3v. There are a number of great questions below, read them through to understand whats going on. ...
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1answer
102 views

Raspberry, relay and GND

I have a relay that I can activate it with a PIN to GND. I have connected that relay to a separate power supply, different from the used for the raspberry. As I have read, I can't supply GND using ...
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0answers
425 views

Relay and Raspberry Pi connection advice?

I have read quite a few threads regarding this same subject with varying answers.I plan on using the relay to turn on and off a 3d printer.I have read a few threads stating that the 3.3v from the ...
1
vote
2answers
409 views

can't set gpio to low, trying to control single channel relay (raspberry pi b+)

I am trying to control a relay using a very simple python code: import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BCM) GPIO.setwarnings(False) GPIO.setup(27, GPIO.OUT) GPIO.output(27, GPIO.HIGH) ...
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2answers
14k views

Using single 5V relay (jqc-3ff-s-z) - safety advice required

Above is relay I'm using and everything works as expected using diagram below. I will add 1n4148 diode on IN line for safety and will connect VCC to power supply before Pi. Can I use ground (GND) ...