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A relay is a part that acts like a switch that can be controlled by an Arduino. They usually are powered by sending current through a coil, which moves a piece of metal to touch a contact within it. (Note there are also solid state relays which act more like a transistor.) The moving parts is why ...

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1answer
29 views

Problems with NodeMCU and Relay

I've connected the MCU to a cheap chinese 24/12v to 5v car phone charger and hooked some wires to a relay.When I try to program doesn't matter if the pin is set to high or low , as soon as I touch the ...
0
votes
3answers
68 views

Can multiple Arduinos be connected to a single relay?

I have a 16 channel relay that will basically manage 16 different contacts. However, each channel in the relay needs to be controlled by an individual Arduino. So in total I would have 16 different ...
1
vote
1answer
29 views

Safely powering a relay from same source as attiny/arduino?

My project involves using ATTINY to control a 5v relay (specifically JZC-11F and will be ground triggered) in an automotive setting. I keep seeing the warnings of powering a relay from the same ...
0
votes
2answers
16 views

Relay does not trigger

Its my first attempt to work with relay I tried to test my relay with this simple code int Relay = 2; void setup() { // put your setup code here, to run once: Serial.begin(115200); pinMode(...
0
votes
2answers
46 views

5v relay module

I'm using NodeMCU with 5v relay module. my problem is that when the output of NodeMCU is high the relay is off. Which means that the relay module work in an inverted way so how can I treat this issue ...
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vote
3answers
44 views

Touch Sensor - Determining Pressing/Hold Length and Modifying Program Flow Accordingly

The code below is used for controlling a relay with an Arduino. Pressing the touch sensor connects and disconnects the relay. If the user presses/touches/holds their finger on the touch sensor for ...
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votes
1answer
67 views

Arduino Uno Motor control using 2 Relays, 2 Limit switches and Bluetooth. Forward Reverse Stop

Modified existing project from this link: Problem : Trigger limit switch to stop DC motor I modified this code to control two relays which are wired to motor poles for Forward or Reverse movements ...
0
votes
1answer
20 views

“Active LOW” relay board Pin configuration [duplicate]

I bought a 5 V Relay Board: LINK (Aliexpress) and just realised it's "Active LOW". I want to control a water pump via a Arduino Micro. I tested it and as far as i understand the workings of this ...
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votes
1answer
44 views

Controlling two-pole contactor using Arduino [duplicate]

I am working with Packard C230C contactor to develop own EVSE. For a simple start i just want to toggle contactor using Arduino. OpenEVSE is already doing it. Just want to know how do they do it and ...
-1
votes
2answers
67 views

Understanding how to power objects with a relay (featherwing, feather huzzah)

I am trying to learn how to control a relay to power various household objects. I bought a power relay shield for an adafruit feather huzzah, and I have just set up the arduino blink sketch to provide ...
0
votes
0answers
19 views

Arduino 24v I/O Shield

I'm searching an arduino uno shield that will allow to communicate with industrial grade PLC and sensors (24v). Something like https://github.com/TheDIYGuy999/Mega_PLC/tree/master/Digital_Input_Board ...
0
votes
1answer
48 views

Combining two different coding program into one sketch [closed]

Im working on project that uses a relay module,arduino atmega328 and a 2 motor 12vdc. based on coding i give, the first code is the motor 1 will run based on the input switch. and the second code the ...
1
vote
1answer
40 views

Relay Board making Output Signal Weak

I am using an Arduino Uno and Relay Shield (http://www.seeedstudio.com/blog/2013/02/28/shield-evolution-flexible-add-ons-for-arduino/relay-shield/), and using a code similar to the Teapot Demo, in ...
0
votes
1answer
28 views

Arduino Wall Wart and Relay Board Power Supply

I am relatively new to Arduino, and have been doing a project to trigger an LED/alarm when movement is detected to be over a certain threshold value. I am using an Arduino Uno, an LED/buzzer (https://...
0
votes
1answer
17 views

Using a channel relay

im using 4 channel relay to switch the motor pump. but when the arduino output is high and i check first with led. the led behavior were high too but when i attached to the relay input IN1, the ...
0
votes
2answers
49 views

Relay with mechanical fallback

In my circuit I have a relay that will turn on some light bulbs this is my circuit: The switch over the 5V is in fact my Arduino. A HIGH will turn on the relay and a LOW will turn it off. This is ...
0
votes
1answer
105 views

Wemos D1 doesnt drive Relay [closed]

I recently bought a Wemos D1 board and tried to connect a relay and test its connection. I got an example server from here and executed. I connected D5 to a Relay's data and 5v and GND from Wemos ...
0
votes
1answer
46 views

Optimal and Save Water Pump Control

I'm using an Arduino Micro, a 12 V water pump and a print relay to water a plant. A water level switch monitors the the water tank to make sure the water pump does not run dry. I tried different ...
0
votes
0answers
146 views

Trying to use NodeMCU ESP-12e, a 5v relay AND a solenoid lock on same 12v power wall-wart

Noob here, so be gentle. Using a 12v-5/3.3v power board, NodeMCU powers relay fine, 100% of the time. Add in the solenoid by soldering a line from the wall wart into the COM spot on the relay, and ...
0
votes
0answers
33 views

ESP8266 WiFi Module disconnects from WiFi itself

#define id "qwerty" #define password"123456789" int relayPin= 4; void setup() { Serial.begin(115200); Serial.println("AT"); pinMode(13, OUTPUT); pinMode(relayPin, OUTPUT); delay(3000); ...
0
votes
2answers
252 views

Right PIN to activate a wireless relay with ESP8266 ESP-01

I'm trying to program an ESP8266 ESP-01 module to let it connect to my personal wifi network and activate a wireless relay that I've bought. No problems with Wifi connection so I've omitted the code ...
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votes
0answers
18 views

Relay modules expansion [duplicate]

I successfully setup my Arduino to control a linear actuator using an 8 channel relay module. the next step of my project requires that I will operate and control 36 linear actuators in parallel. I'm ...
0
votes
2answers
49 views

Two power source for Arduino and a relay

In my work, I have an ESP-8266, Arduino-Uno and a Relay. ESP 8266 and Uno is connected. Relay's data signal is take from arduino's 12th pin. ESP is powered from Uno. If I use two different power ...
0
votes
1answer
129 views

Powering 8-channel relay correctly

Replication Steps: 595N shift register powered by arduino Each output on register connected to 1 of 8 relays in relay board Arduino programmed to loop over each 8, triggering 1 relay at a time ...
0
votes
1answer
49 views

Can someone help me with my arduino and relay and switch?

This is my code. What i want to do is activate the relay when switchInNcPin is activate. I am using a switch (micro switch). It has COM NC and NO pins. Can you tell me what is wrong with my code? ...
1
vote
1answer
368 views

Wemos: relay shield doesn't work on top of the stack

I connected a SHT30 shield to a Wemos D1 mini (one on top of the other) to measure temperatures. Wemos D1 mini (2.3.0): SHT30 shield: It works great but when I added a relay on the top of the ...
-2
votes
2answers
60 views

How to make an I2C device undetectable

Please bear with me as I am a bit new to electronics and arduino. I am trying to have multiple sensors connected to an Arduino Mega through I2C Bus. That is working but I would like to have the ...
-2
votes
2answers
91 views

How do I get status of contactors using Arduino (more than 50 contactors)

I am new to Arduino. Sorry if my question sounds wrong. Interest areas: Multiple devices inter-connected on the cloud. Single GSM for equipment in a typical panel connectivity for non-electrical ...
2
votes
1answer
98 views

How to control an 12V 2A Car lamp using relay or MOSFET in Arduino [closed]

I am working with the project controlling an 25W 12V Car lamp. I have a 12V car battery. I want to control it with the Arduino using a relay or MOSFET. Any suggestion for my project would be ...
0
votes
1answer
97 views

Preventing relay switch-off crashing Ethernet controller

I have an Arduino Uno with Ethernet Shield controlling some relays. Initially everything works fine but then when switching the relay off, the Ethernet controller frequently 'crashes'. Ethernet stops ...
0
votes
1answer
49 views

LED staying on after first relay trigger [closed]

I seem to have a strange issue with a simple circuit involving a relay. The problem is that the relay appears to work absolutely fine (judging from the onboard led) but the the led stays on after ...
1
vote
1answer
48 views

Arduino controlled relay for certain duration of time

I am using a relay on my Arduino Uno and i want it to be on LOW for a calculated interval of time, let's say ftime=7 seconds, and after that i need it to be set as HIGH (no power through relay). My ...
1
vote
1answer
516 views

Relay active low and ESP8266 GPIO pins

I am using a ESP8266, specifically the ESP-12-E : I have a Relay, SRD-05VDC-SL-C connected to GPIO pin 4. It is wired in Normally Open(with my device to be powered wired into the top and middle pins ...
2
votes
2answers
416 views

ESP8266 disconnects after few hours

My system looks like this: ESP8266 is connected to Arduino Uno (2, 3 pins) and a relay's data input to Arduino's pin 12 and power for relay is provided from another source. Arduino gets data from ...
0
votes
2answers
161 views

Alternative of relay

I am carrying out a physics experiment using an Arduino. This experiment requires accurate time measurements of upto a millisecond. However I am using a relay to turn on/off an electromagnet and there ...
1
vote
3answers
142 views

Looking for link to Double Pole Single Throw (DPST) relay for Arduino

Need to find a DPST relay that is 'Arduino' friendly and that is capable of 30A at 240VAC. Anyone can share links ? Not looking for recommendation, just ideas on what you saw or used in the past. ...
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votes
2answers
1k views

Can I use a 3.3v GPIO to control an opto-isolated 5v relay board?

I am working on a DIY home automation project using a Wemos D1 Mini as the controller, and I ordered some 4-channel 5v-triggered relay boards. The ESP8266 that Wemos D1 Mini's are built on has GPIO ...
0
votes
0answers
260 views

How to power a 12V linear actuator and control it with buttons?

This is my first time in arduino.stackexchange I have an Arduino Uno. I need to use an electric linear actuator to control the movement of a joint in which I have installed a rotary encoder to know ...
1
vote
2answers
374 views

Arduino & RPi communication via GPIO [closed]

so I'm working on communication between arduino and RPi via GPIO pin. It's basically connecting them by using a cable jumper. So I have a 2 channel relay shield attached to my arduino, and I've been ...
1
vote
1answer
103 views

Problem with simple coding for PLDuino: trying to turn relay on and off

I am writing the following, simple code to try to turn a relay in the PLDuino on and off, and it is giving me warnings and not compiling/uploading. Any help would be greatly appreciated. Here is my ...
0
votes
1answer
60 views

Arduino relay power supply question

Hello everyone i got 2 ssr's from here (link) Sorry about the long link. My question is what power supply should i use. I was thinking a 12v 2amp. On a side note do i look at the input or the output ...
1
vote
4answers
98 views

Need assistance decyphering agriculture systems control code created by absent team member

I'm working on an agriculture system and one of my partners (who was taking care of the automation side of things) has gone MIA and we are left with arduino code running our systems that we have a ...
0
votes
0answers
34 views

Wiring a RT314F12 latch relay to an Arduino

I want to automate the lights in my house. To do this, I want to use a latching relay, so it will only use current when switching. I found a quite cheap latching relay RT314F12 but I do not know how ...
1
vote
1answer
75 views

Description about arduino relay

I have this relay module. I don't understand what is a role of the jumper on it (for now it's shorting the jd-vcc (what??) and vcc pins).
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vote
0answers
75 views

Simple relay switching program crashes UNO

A very simple digitalwrite(pin, HIGH) delay(1200) digitalwrite(pin, LOW) delay(1200) crashes the uno after about half an hour. Of course it works again after pressing the reset button. It's ...
0
votes
1answer
43 views

Do I need a relay to control a monitor's power with an Arduino?

I'm trying to use an Arduino to switch a monitor's power on and off. I'm going to wire the Arduino to the monitor's power switch. I've tested the power switch with a multimeter, and when pressed, ...
0
votes
3answers
63 views

How to embed a 5V-range Arduino-based controller in a 12V-range DC circuit?

We have an installation that provides: a common line (C), which divides into two wires; an input line (I), which carries the signal from a button (between I and C there's normally 0V, and 12V when ...
1
vote
3answers
139 views

Problem with Dual Safety Switches Initiating Timed Relay

I have been working on an Arduino project that has me kind of stumped. What it needs to achieve is that two momentary safety switches need to be pushed and held within a specified time frame as ...
0
votes
0answers
163 views

acs712 zero point problem

I have Arduino Uno R3 with: Ehernet shield 4x ACS712 20A boards measuring AC current 4x relay board. Power supply is wall mount USB adaptor 5V 2A. If all relays is off, measured voltage in arduino ...
0
votes
1answer
155 views

MCU to switch single coil latching relay not working (attempting array with common gnd)

I have several single coil latching relays, (EC2-5SNU). I am trying to control them by an MCU; connected directly they work fine, but I am iffy about keeping it this way so I'm trying to power them ...