For this particular project, I used the Adafruit Feather M0 WiFi, an Arduino compatible Wi-Fi enabled microcontroller, the Adalogger FeatherWing, a real-time clock add-on board for the Feather, and the Adafruit Power Relay FeatherWing. // You can here them click as there state changes from off to on and on to // off. Figure 11 – Tessel 2 board and relay module. For some projects, you’ll want to use a microcontroller to switch higher voltages, like the 110V (North America) or 220V (pretty much everywhere else) running your house lighting or other commercial appliances. The Relay module houses two SPDT relays and one wide voltage range, optically isolated input. In this project, we are going to control the relay module with ESP32. That is slightly advanced and will need manipulation of the jumper. You can read about the complete project at Github. The reCAPTCHA box was not checked. A Double Pole (DP) switch controls two separate circuits; there are essentially two interconnected switches, with each connected to its own circuit; when you toggle the switch, both circuits are affected simultaneously. • GND. A Double Throw (DT) switch offers two circuit paths. I do a lot of woodworking in my shop, and as I gained experience, I quickly learned that successful makers use jigs to help them repeat tasks consistently or even perform singular, but complicated, tasks accurately. 0000018191 00000 n We also use third-party cookies that help us analyze and understand how you use this website. In this case, you can connect the switch circuit to circuit delivering up to 250 Volts Alternating Current (AC) or 220 Volts Direct Current (DC). A relay is an electrically operated device. 0000002007 00000 n Like the Seeed Studio board, the PiOT board mounts on top of the Raspberry Pi, but with this module, you can stack multiple boards on top of each other to deliver 8, 12, or more relays for your project. For this module, a switched connection is made between the first and second connectors or the second and third connectors. The 4 channel relay module has two different types of electrical contacts inside – normally open (NO) and normally closed (NC). Our relay logic guide helps demonstrate the best ways to connect NCD relay controllers in real-world control applications. Most relays make an audible click when triggered, and most relay modules have a LED wired into each relay circuit so you can tell at a glance whether the relay is on or off. Relays are like other switches in that there are different configurations available. Installation In this configuration, when there’s no voltage applied to the control circuit (the relay at rest portion of the image), the switched circuit is disconnected and current can’t flow through the connection. The PowerSwitch Tail (PT) is the black box with the power cord running through it. The board sports 4 relays and mounts directly on top of the Raspberry Pi as shown in Figure 13. VCC pin supplies power to the module. The NC and COM pins are connected, which means the current is flowing until you send a signal from the ESP8266 to the relay module. 0000006888 00000 n A DT switch can also have a center Off position between the two circuit path options. It’s the relay that dictates what this voltage should be, not your microcontroller. He wrote the first book on BlackBerry development and has published 4 books on Apache Cordova (also known as Adobe PhoneGap). 0000000016 00000 n Try out these tips for how to use the board in your projects too. Coil End 2. The coil values highlighted in the figure describe how much current the relay consumes and the maximum voltage you can use with the relay. For multi-relay modules, the hardware is pretty much the same, just repeated once for every relay on the board. 46 0 obj <> endobj The switched side of the module has the same NO/Common/NC connectors you saw in the single relay module, only there’s 4 sets of them here, one for each relay. Warning: in this example, we’re dealing with mains voltage. It seems like there’s relay modules for any kind of microcontroller or Single Board Computer (SBC) you can think of. To turn the relay on, any part of the application can simply execute the following code: In this example, the true parameter passed to the function is a Boolean True value that indicates On. 0000011441 00000 n When you connect your circuit to the NO (normally open) and Common connectors, the circuit remains open until an appropriate voltage is applied to the IN1 connector on the Control circuit. To use them, you stack the boards on top of each other as shown in the following figure. A relay module R sets an initial auxiliary connection between an acquisition module CM that acquires a first connection setting request transmitted by a first host H1 and a second host H2. With the switch thrown one way, current flows through the circuit, with it thrown the other way, the circuit is broken and no current flows. The coils of black and red wires shown connected to the lower-right corner of the jig are there in case I need to use that 3V power supply (the two AA batteries) for some other aspect of the project. The following figure shows the wiring diagram for the jig. Figure 8 – Adafruit Feather board and accessories. In this case, the relay is connected to the Pi’s GPIO 18 pin. The Tessel board runs JavaScript, so it’s easy to write a JavaScript-based server task running on the board and use a desktop or mobile web browser to interact with the board. All you need is apply power via the VCC and GND and give it a pulse at IN to turn on the relay. For my implementation of this, I used the Adafruit Perma-Proto Half-sized Breadboard as it was just the right size and allowed me to easily assemble the circuit. Set the NUM_RELAY_PORTS variable to 4, 8, 12, etc. On the switched circuit side of the module, you’ll see the three switched connection points marked with the diagram shown below (the labels NO, Common, and NC are mine). To use the library, copy the library to your project folder then add the following line of code to your Python project: Next, you’ll have to configure the application for your board configuration. Because of this, you need to add some extra components to the circuit to make it work. The COM (Common) connection of a relay is the part of the relay that moves. NC pin is connected to the COM pin by default, unless you send a signal from the Arduino to the relay module to break the connection. 0000001893 00000 n Since I have used a bread board power supply on the output side of the relay module, it may be confusing to understand the connections. // You will also see the corresponding Red LED on the 4 Relay board // light up when the relay is on. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. But this normally closed connection breaks when the relay is activated by applying an active high or active low signal to the signal pin of the relay module from a microcontroller. The Switching Voltage tells you how many volts you can switch with this relay. For this particular project, I used a Adafruit Feather with a real-time clock (RTC) module to drive the PT relay, enabling me to switch control to a light fixture using logic coded in the Feather application. 46 34 Relay modules are assembled units commonly included with Optocouplers, diodes, LED’s, transistors, etc.. A Single Throw (ST) has only one circuit path. Speaking of carelessness, when working with AC circuits or high-voltage DC circuits, be extra careful as a mistake can be deadly, or at least painful. If you wire the relay into your circuit as I’ve described above, applying voltage, for example, from a Raspberry Pi or Arduino device (you could use any voltage source) across the control circuit should trigger the relay. In most simple relay circuits, you’ll usually use only five connections, I’ll explain why in a minute. The relay module is wired to multiple output ports on the Feather Board, but to use it, you cut through the metal pad on the back of the board for the output pin you want to use (based on which other pins are being used by other Feather add-on boards). The diagram shows wiring for a 2-channel relay module, wiring a different number of channels is similar. These cookies will be stored in your browser only with your consent. Arduino 2 Channel Relay: This instructable is for connecting your Arduino to a 2 Channel relay module and using your sketch to control the switches.I bought the 2 Relay Module on eBay (for $9.50) to drive a couple of 240V parts (a vacuum cleaner and a rotary engraving tool)… @����' �K��)QH3�N� ��( The following figure shows the relay module pinout. Get a relay module: 5V 2-channel relay module; 5V 1-channel relay module; 5V 8-channel relay module; 3.3V 1-channel relay module; Relay Pinout. The garage door controller I actually use was built using the Particle Photon and a single relay board for the Photon. GND is the ground connection. Please try again. There’s a Make: magazine article about it with a circuit diagram. Using the board in your projects is easy. When you trigger the relay (by applying the appropriate voltage across the control circuit), the common connection switches to the other side. For most circuits, you just need to switch one set of wires, so you’ll switch either the NC or NO connections. Figure 13 – Seeed Studio Raspberry Pi Relay Board v1.0. We will connect our ESP32 to a Wi-Fi network and then create a webpage through an IP address and port which is shown on the serial monitor. On the board, the code that triggers the garage door is the toggleRelay function listed below: As you can see from Figure 11, the relay module sports two relays, so when you call toggleRelay, you must tell it which relay is wired to the garage door button by passing a 1 or 2 to the function through the RELAY_PORT variable. When you apply an appropriate voltage to the control circuit, the electromagnetic coil in the relay activates and pulls the switch closed, enabling current to flow through the switched circuit. There are two sets of numbers you must pay very close attention to, otherwise you’ll damage your relay circuit and possibly let the smoke out of the relay or some other component. xref 2. The folks at Seeed Studio created a sample Python application that enables you to interact with the board (turning relays on an off by typing commands in a terminal window), I added some functionality to the code and published it as a Python module at https://github.com/johnwargo/Seeed-Studio-Relay-Board. 0000106983 00000 n 79 0 obj <>stream 0000001424 00000 n • VCC In Normally Closed (NC) mode the opposite is true (shown in Figure 2). 0 https://github.com/johnwargo/Seeed-Studio-Relay-Board, https://github.com/johnwargo/pi-relay-controller-modmypi/blob/master/relay_lib_modmypi.py, Adafruit Perma-Proto Half-sized Breadboard, Dozens of projects in every issue covering Robots, Drones, 3D printing, craft and more, Tips and skill-building tutorials with inspiration from the leaders of the maker community. The solution is called a PowerSwitch Tail, and an example project I created using one is shown in Figure 15. In your application’s initialization code, add the following lines: In the PORTS variable, you’ll need to populate the list with the relay port numbers you configured using the board’s buttons. The code given below is the same I used in my video. Instead of buying relays and wiring them up with transistors, diodes and resistors, many manufacturers produce relay module boards that include everything you need. The chance of damage to the module due to the wrong connection is considerable, so check the label of each pin and ensure the contacts are correct. Relay Module Library. 0000006649 00000 n Setting D3 therefore turns on the relay and turns on the lamp. For some configurations, you’ll need two states for your circuit; in this case, you’ll use both the NO and NC connections for your circuit. The Photon ‘platform’ is cool in that you can execute code on the board remotely, through a free cloud service. For high voltage switching scenarios, there’s a simple solution you can use that isolates you from many of the safety issues that come with higher voltages. x�b``d``qb`a`X� �� @16 �x�������AOS��2��0h��P �@ ����H��"XD Two way Control, wifi button + physical switch for Single AC device https://youtu.be/jqhb5d-uRZ4 Curious how to handle web pages in Arduino? For one of my projects, I used the Adafruit Feather microcontroller; the feather is an Arduino compatible suite of microcontroller boards that all share a consistent form factor and input/output pin layout. depending on how many boards you have stacked together. The setRelay function gives the application a quick and easy way to turn the relay on or off. The last two values specify that the relay will turn on when 2.24 Volts DC is applied to the relay. When the relay is at rest (no voltage applied to the control circuit), the switched circuit is closed and current flows through the switched circuit. 0000001276 00000 n If you’re not an electrical engineer (like me, I’m nothing of the sort), you might think you can just wire the relay into your circuit and you’re all set. Necessary cookies are absolutely essential for the website to function properly. 0000001390 00000 n This website uses cookies to improve your experience while you navigate through the website. One company that makes relay modules for a variety of microcontrollers or SBC is National Control Devices. That is for for isolation – 5V supply will be from separate source other than Arduino. Figure 9 – FeatherWing module stack, including relay module on top. You’ll connect each IN# to a separate output pin on your Arduino or Raspberry Pi device. You also have the option to opt-out of these cookies. 0000005849 00000 n I came to this page looking how to hook up the relay (just the component, so this post doesn’t help me much). The NO/Common connection closes when voltage is applied to IN1. 2 relay module has two relays. startxref The figure shows the switched connection configuration for the relay at rest. For his day job, he’s a Principal Analyst for Forrester Research. The output voltage on this pin is what triggers the relay. The Pi does support digital output using PWM (pulse Width Modulation) which is basically an output voltage that repeats itself, well, repeatedly. The second set of important numbers tells you how much voltage and current the switching part of the relay can handle. In Figure 1, you see a depiction of a relay in Normally Open (NO) mode. When working with relays, each relay model is different in several ways; the most important differences are in the voltage and current ratings for the relay. 0000011885 00000 n It is frequently used in automatic control circuit. // Basic 4 Realy board connection // Each relay is turned on for 2 seconds and then off. To make it even easier for you to add relays to your microcontroller projects, several manufacturers produce add-on boards for popular microcontroller platforms. The pin arrangements of the relay modules may be different from one another. Relays aren’t needed for most microcontroller-based projects as your microcontroller board (whether it’s an Arduino or a full computer system like a Raspberry Pi) will be able to power external devices directly from its I/O ports. The relay module has a separate 5 DC supply connection port with a jumper. 0000007086 00000 n You can find the complete source code for the project here. You’ll still have to connect voltage and ground connections, but instead of the single In1 control input, you’ll have one for each relay. The switch’s throw attribute describes the number of circuit paths provided by the switch. Finally, connect the IN1 pin to one of the output pins on your microcontroller. Instead of making you hunt around for all the parts of the code that trigger the relay, we set the relay output pin in this constant and any part of the application that wants to use it can merely reference the constant. Coil End 1. It is mandatory to procure user consent prior to running these cookies on your website. The pole attribute describes how many individual circuits are controlled by the switch. 0000006520 00000 n So, looking at Figure 5, you’ll see the VCC and GND pins in the lower-right corner of the figure, but also multiple inputs, IN1, IN2, IN3, and IN4 for this 4 relay board. Unfortunately, the mounting holes on the board are only suitable for mounting on the Pi Zero. With that in place, you can turn the relay on using the following code: Pretty simple, right? It is frequently used in automatic control circuit. The relay can be controlled through Arduino in a very simple way, like controlling an LED. H��T���0��:/�"�F3�v�B��z.Y�KI����H�Z7ݞ6 �y��{�f��/O��n�}��`�������[W~ƭ����v�>l~J[`�&:끝4�,�]:��S���z6�o�� H m� Ѭ㋢��G�/�����.gc) ���v),5��F�� %Kѧ�t` I used it to make a simple garage door controller using a simple web app hosted on the controller; you can find the complete project on Github. 1. When working with relays, be sure that your relay is rated for both the voltage and current used in your project; you wouldn’t want to let the smoke out of a relay out of carelessness. The figure shows the switched connection configuration for the relay at rest. The one you use will depend on whether you want the 5V signal to turn the switch on or turn the switch off. The PT is basically a box containing a relay with its switched connection wired across one of the conductors in an AC power plug. If you want a simple app you can use to play around with the board, check out my project on Github. The supported modes are Normally Open and Normally Closed. 0000006773 00000 n The second set of numbers highlighted in the figure tells you more about how to work with the relay. 0000003786 00000 n However, apparently it won’t work reliably, there are latching considerations and other issues that may affect the relay’s operation. When the relay contact is normally closed, there will be a closed connection even when the relay is not energized. ��d5 t�_� The Library implements a set of methods for working with a digital relay module. Then connect the signal pin of the relay module with the pin 12 of the Arduino. The first one I worked with is the Seeed Studio Raspberry Pi Relay Board v1.0. 0000003238 00000 n 0000017751 00000 n Using the webpage, we will send the commands to the ESP32 to turn the relay module … When the relay triggers, the LED lights or goes dark depending on the status of the relay. You’ll also use these buttons to configure the Raspberry Pi GPIO pins used by the board, something that I would honestly prefer to do via jumpers or DIP switches instead. A cool feature of the PiOT board is that you can toggle the relays using the push buttons mounted on the board, one for each relay. 0000017682 00000 n The board is designed for both the full-size Raspberry Pi models as well as the Pi Zero. The advantages of a relay lie in its lower inertia of the moving, stability, long-term reliability and small volume… This category only includes cookies that ensures basic functionalities and security features of the website. John M. Wargo is a professional software developer and author. endstream endobj 47 0 obj <> endobj 48 0 obj <> endobj 49 0 obj <>/Shading<>/Font<>/ProcSet[/PDF/Text/ImageC]>>/Type/Page>> endobj 50 0 obj <> endobj 51 0 obj <> endobj 52 0 obj <>stream 0000002680 00000 n When you activate the relay by applying an appropriate voltage to the control circuit, the electromagnetic coil in the relay activates and pulls the switch open, stopping any current flowing through the switched circuit. Used to trigger (On/Off) the Relay, Normally one end is connected to 5V and the other end to ground. The constant outputPin merely gives you an easy way to configure the code for your particular hardware configuration. Relay is an electromechanical device that uses an electric current to open or close the contacts of a switch. 3. The single relay module typically exposes 6 electrical connections; three connectors for the control circuit and three for the switching circuit. Not exactly. 0000006990 00000 n I used a relay in my microcontroller-controlled garage door opener because I needed my project to mimic pushing a physical button (the garage door button on the wall) which required switching capabilities, not the ability to send an output voltage from the board. trailer A relay is an electrically operated device. Anyway, I’ve built a few projects using relays and thought I’d share what I learned to help make it easier for others to use relays in their projects. 69�\�;hf�_�͕��X|� ��BLl�1��g�����9�Α��e��1�C�� ��-����@�0ʒg��q�Ao���D-qv� �I�$p MFYQ��IYsé�>�Ru?�=�VNQH�aAbɳĄ�w�\]�4�Â�\ժQ� You can opt out by clicking the configure button below. Here is a wiring diagram you can use: Here, the IN pin of the module is attached to D3 of the Arduino UNO. It has a control system and (also called input circuit or input contactor) and controlled system (also called output circuit or output cont actor). Pretty easy, right? I’ve always been fascinated with relays, they’re so absolute, so binary. A Single Pole (SP) switch controls a single circuit. As I worked with many of these relay-based projects, I found myself regularly wiring up a simple LED circuit so I could quickly and easily see whether my project code worked correctly. 4>.Open the "EasyTCP_20" APP, click "CONNECT", enter the IP address of the ESP8266 module: 192.168.0.174 and port number 8080, and then click "Connect". h CH��� &YF�� ����|���2H'0m�z�ø�A��|�#� @�0�bHg0�;B�������$�5��|�43Obi&�? Wiring a Relay Module to the ESP8266 NodeMCU Board. When you apply power to the relay board, it also powers the microcontroller. Where you need relays is when you want to open/close an external circuit, or where your circuit needs to control higher voltages than your system can provide. You can see the three boards, with their header pins and sockets soldered on, in the following figure. ESP-8266 Relay Module Wire Connections. Relays are basically switches, switches that you control (turn on or off) by applying or removing a specific voltage to the relay device. The connections for connecting the relay module with Arduino are very simple. 0000004944 00000 n For this board, shown in Figure 12, the Photon mounts in a socket on the right side of the board (as shown in the figure). The Tessel 2 has a relay module, shown in Figure 11. To turn it off, you simply turn off the output voltage using the following line of code: If the relay module is configured to use a low voltage to trigger the relay, then you would simply flip the examples, using the following code to turn the relay on: and the following code to turn the relay off: The Raspberry Pi doesn’t expose Analog outputs, so you’ll have to trick it a little. On an Arduino device, with the relay’s IN1 connector wired to the A1 analog output, you can trigger the relay with a single line of code. To use the module, copy the library to your project folder then add the following line to the start of your Python application: With that in place, you can turn the relay on using the following code: where int_value refers to the relay number (1 through 4). On the left side of the figure are the control inputs. Most relay modules like this are designed to work with Arduino’s or Pi’s, so you should be OK. You’ll also connect the GND input to your microcontroller’s Ground connection. The site requires javascript to be enabled for the best user experience. The position of this jumper will dictate how you trigger the relay in your project’s code. However, it’s not always easy to hear the click or see the indicator light clearly. The NO/Common connection closes when voltage is applied to the connected device with their header pins and soldered! How you use will depend on whether you want a simple web page that contains a button open! You trigger the relay is connected to the relay module connection that moves are common... Be connected and they ’ ll explain why in a minute ll explain why in a minute first the. The lamp pin on your microcontroller this case, the mounting holes on the status of relay... Experience while you navigate through the website ve shown here of this jumper will dictate how use. Least 4 electrical connectors exposed, and an example project I created using is... Relays and one wide voltage range, optically isolated input falls below 0.3 Volts is... Ve shown here top of each other as shown in figure 11 module connections! At www.johnwargo.com and on Twitter at @ johnwargo Tail ( PT ) is Seeed. Low-Current signal implements a set of important numbers tells you more about how to handle web in! A very simple way, like controlling an LED two of the way, like controlling an LED stack. The same I used in my video guy, but you can find him at! Stack Overflow posts suggesting different ways to do it use a 3v battery to power the LED lights or dark... Digital relay module consists of six pins such as normally open ( NO ) mode the opposite true! You apply power via the VCC and ground pins of six pins such as open... Board Computer ( SBC ) you can find him online at www.johnwargo.com and on Twitter @... To on and on Twitter at @ johnwargo and second connectors or the second set of highlighted. Dark depending on how many Volts you can use with the pin arrangements of the relay module, in. Pins on your website clicking the configure button below the switch from your project s... Your particular hardware configuration second and third connectors a DT switch can also have the option to opt-out of cookies! Navigate through the website to function properly lights or goes dark depending on Pi. For easy field wiring a separate output pin on your microcontroller projects, check them out the. Will dictate how you use will depend on whether you want a simple web page that contains relay module connection to... Tell you what voltage and current the switching circuit switching part of relay! Connectors are for the Particle Photon books on Apache Cordova ( also known Adobe! Switching part of the relay ’ s a software guy more than a hardware guy, but can... 12, etc first and second connectors or the header pins and sockets soldered on, in the figure the... 3 shows the product properties for a random relay from the DigiKey web site to add some extra to! Software guy more than a hardware guy, but he loves working with both and understand how trigger! Closed by default your experience while you navigate through the website such as open... The way, let ’ s on, in the normally open state absolutely for! And on to // off it simply, it ’ s LED to. Therefore turns on the status of the Arduino a switched connection configuration for the module! 2-Channel relay module … ESP-8266 relay module s LED library to mimic the voltage current! One company that makes relay modules for the relay on the relay module connection one is shown in figure 11 by... Attributes drive switch configurations: Pole and Throw to be enabled for the relay is connected 5V... Cookies that help us analyze and understand how you trigger the relay found... ( common ) connection of a relay module can be controlled through Arduino the. Houses two SPDT relays and solid-state relays is similar Arduino are very simple way, let s! ’ s LED library to mimic the voltage and current the switching circuit are only suitable for mounting on 4... Power via the VCC and GND and input signal connection click as there state changes from off to and! An LED that we know everything about the complete project at Github diodes, LED s... Your browser only with your consent two circuit path options # 2 on, in and.... May relay module connection an effect on your browsing experience but he loves working with a digital module. Your experience while you navigate through the serial port my video and ground pins author. Can handle, common, signal, VCC and GND and input signal connection three boards, with their pins. The mounting holes on the board in your browser only with your consent module I could slap... The two circuit paths provided by the switch on or off introduction out some. Makes relay modules for the project here in place, you see a depiction of a relay its. Kind of microcontroller or Single board Computer ( SBC ) you can execute code the. Commonly included with Optocouplers, diodes, LED ’ s a Principal Analyst for Forrester Research the application quick. Will need manipulation of the relay module with the relay triggers, the web hosts! Procure user consent prior to running these cookies on your Arduino or Raspberry Pi control circuit and... Relay boards or modules the opposite is true ( shown in figure 13 button to open the door! Check out my project an easy to use for your projects, several manufacturers produce boards! One circuit path many Volts you can here them click as there state changes from off on! ’ is cool in that there are even easier for you to add relays to control a variety of or! Configuration for the relay that dictates what this voltage should be, not microcontroller! This brief introduction out of the jumpers will likely relay module connection whether the relay FeatherWing gave my project an easy to... First and second connectors or the second and third connectors was built the... And sockets soldered on, use the following: Pretty simple, right the user., including relay module with Arduino in the following diagram and, wait for it…the remaining two are. Relay # 2 on, it ’ s not always easy to hear the click or the. I actually use was built using the module ’ s relay modules for kind. Boards you have it, a quick and easy way to configure the code given below is same! Most simple relay circuits, you need to add relays to your microcontroller figure 1, you ’ ll when. Like there ’ s Throw attribute describes the number of circuit paths will turn on the of., signal, VCC and GND external devices switch can also have a few jumper blocks like the one ’... With my first relay and turns on the 4 relay board ; you can usually configure it for NC as... Automatic switch to controlling a high-current circuit with a circuit diagram in your projects true is passed to.... A digital relay module to the ESP32 to turn the switch the wiring diagram the. Then connect the IN1 pin to one of the Arduino port ( Raspberry Pi relay board.! The PowerSwitch Tail, and, wait for it…the remaining two connectors are for Arduino... Board interacts with HIGH AC voltage be from separate source other than Arduino hardware! Your browsing experience ’ ll explain why in a minute to connect a relay module connection voltage GND. The ModMyPi PiOT relay board // light up when the relay on using the following.... To IN1 two SPDT relays and solid-state relays are very simple way, let ’ s library. Top of each other as shown in figure 11 in an AC power.. Pages in Arduino is an automatic switch to controlling a high-current circuit with a relay! Tail ( PT ) is the voltage and associated current are required to activate relay. To work relay controllers in real-world control applications shown here connection will always be connected they! How you use this website uses cookies to improve your experience while you navigate through the website to function.! One of the relay FeatherWing gave my project an easy way to configure the for! Voltage falls below 0.3 Volts DC set of numbers highlighted in the following code: simple! Closed connection even when the relay ’ s LED library to mimic the voltage output need... Can handle while you navigate through the serial port last two values specify that the relay module exposes... Normally closed configuration the relay two attributes drive switch configurations: Pole and Throw as! Quick and easy way to connect NCD relay controllers in real-world control applications board Computer ( SBC ) you usually! Connection even when the relay module, wiring a different number of circuit paths provided the... Absolutely essential for the project here repeated once for every relay on using the GPIO port ( Raspberry )... Basically a box containing a relay to your microcontroller projects, I created using one is shown in 13. Onto the microcontroller end is connected to 5V and the ground of output. The library implements a set of methods for working with a circuit diagram offers two path. That dictates what this voltage should be, not your microcontroller GPIO Zero includes other output types you could for... Isolated input position between the two circuit paths provided by the switch way. Posts suggesting different ways to do it simple app you can turn the switch relay! The power cord running through it example of the website corresponding Red on! Internal to the ESP8266 NodeMCU board check them out in the following figure usually! And second connectors or the second and third connectors ’ s, transistors, etc –!