Full Stack RESTful MERN LED Strips

5 Volts relay

Adafruit NeoPixel Digital RGB LED Strip 144 LED, 1m White

Solder Wire, Lead Free

SparkFun Logic Level Converter - Bi-Directional

USB Connector, Micro USB Type B

USB-A to Micro-USB Cable

Wemos D1 Mini

PIR Motion Sensor (generic)

Raspberry Pi Zero Wireless

Capacitor 1000 µF

Jumper wires (generic)

Soldering iron (generic)

FULLSTACKRESTful MERNLEDSTRIP SYSTEM - which means:<ul ><li >The actual LED strips that are controlled by a WiFi-capable Arduino (in my case, a WeMos D1 mini). The Arduino additionally incorporates 2 motion sensors</li></ul><ul ><li >The sever/back-end: a <a href="http://node.js/Express.js">Node.js/Express.js</a> server that runs on a Raspberry Pi (Zero W).</li></ul><ul ><li >The front-end: a React.js based website that lets you control the LED strips.</li></ul><div class="se-component se-video-container __se__float-none" contenteditable="false" style="width: 100%;"><figure style="width: 100%; height: 56.25%; padding-bottom: 56.25%; margin: 0px;"><iframe frameborder="0" allowfullscreen="" src="https://www.youtube.com/embed/mkLFsn1eCeQ" data-proportion="true" data-percentage="100%,56.25%" data-size="100%,56.25%" data-align="none" style="width: 100%; height: 100%;" data-index="0" data-file-size="0" data-origin="100%,56.25%"></iframe><figcaption contenteditable="true"><div>a short clip demonstrating the main characteristics of my server based approach</div></figcaption></figure></div><h3 >WHY I'M USING A FULL STACK ENVIRONMENT TO CONTROL THE ARDUINO</h3>Most projects use a smartphone to directly communicate with the Arduino using apps like Blynk. It is easy to set up but has several drawbacks:<ul ><li >Whenever you unplug the Arduino from the power supply, all settings are lost and you have to re-configure the Arduino with the smartphone.</li></ul><ul ><li >If you want to control the Arduino with multiple devices (for e.g. to control it with every smartphone in the household), you have to install and configure the app on every device. And you will probably run into compatibility issues - one app won't work on all of your devices (MS Windows computer vs Android Phone vs Mac Os Tablet).</li></ul><ul ><li >If you control the Arduino with multiple devices there's no chance to keep the devices' settings synchronized.</li></ul><ul ><li >The sever is able to synchronize the LED strips which is important for animations</li></ul>To overcome theses issues I've implemented a server that runs on a low-cost, power-efficient Raspberry Pi Zero W that handles the entire communication process:<ul ><li >Any changes in settings be pushed to the server.</li></ul><ul ><li >The server saves the changes locally in a MongoDB database and forwards the changes to the Arduino(s).</li></ul><ul ><li >Referring to databases, the system works like a many-to-many-relationship-setting: You can control multiple Ardunios with multiple browser-capable devices.</li></ul>BENEFITS of a server-client approach: <ul ><li >Whenever the Arduino reboots, it automatically and autonomously requests all settings from the server. You don't have to reconfigure the whole Arduino after every reboot.</li></ul><ul ><li >Because I've written all software it is tailor-made and perfectly customized. This gives the opportunity to do more than the usual functionality third party apps support.</li></ul><ul ><li >The server&lt;-&gt;frontend- and Arduino&lt;-&gt;Server-commuincation is effectively a RESTful approach and mainly conveys data in the standardized JSON-format. This way, each of the 3 pillars (Arduino | server | frontend) can be programmed independently. It enables me to define a generic functionality that I might not use today, but that I can easily access at a later point in time. As you know, modifying software on the Arduino requires it to be plugged in to your computer. So you can't change the software on the fly. This is pretty annoying because usually you hide the Arduinos at invisible but unfortunately not-so-friendly accessible spots (in contrast: I can modify the server- and front-end-software running on the Raspberry Pi via FTP and SSH).</li></ul><ul ><li >As mentioned earlier, this system lets you control multiple Arduinos that serve entirely different purposes using only one tiny server that is controlled over a single access point: the website. I've also build a fully automated irrigation (you can have a look at it here: <a href="https://create.arduino.cc/projecthub/MrSoir/fullstack-restful-m-ern-irrigation-system-159338">https://create.arduino.cc/projecthub/MrSoir/fullstack-restful-m-ern-irrigation-system-159338</a>). The same Raspberry Pi server controls the irrigation system as well as my LED-strips and I can control both systems using the same website on any device that is connected to my local WiFi. </li></ul><ul ><li >code-reusability: a large portion of the code that powers the irrigation-Arduio is shared by the LED-strip-Arduino. I've exported most of the code to Arduino-libraries. That makes it really easy and efficient to add more Arduinos to the server-client-environment.</li></ul><h3 >HOW IT WORKS</h3>The Raspberry Pi server provides the website. You can access the website by entering the local ip-address and port (in the default settings the server runs on port 8080) of the RaspberryPi in your browser (<a href="http://raspberrypi.local:8080/">http://raspberrypi.local:8080/</a>). This way, it is possible to control the LED strips from any device that is connected to your WiFi network like your smartphone/tablet/laptop/pc - there's no need to install a 3rd party app. The system is completely platform independent. Being a stingy person I run the server on a low-cost Raspberry Pi Zero W. It is a bit more complicated to install node.js on it, but there are great instructions on the internet on how to get it done.Using the website you can control the Arduino:<ul ><li >\tManually turn on/off the LED strips</li></ul><ul ><li >\tManually (de)activate the motion sensors</li></ul><ul ><li >\tThe server activates the motion sensors when the sun sets and deactivates them when the sun rises. Once a day, the server requests the sunset and sunrise times of the current day over the https://api.sunrise-sunset.org-API. This API is great - you don't even need an account to send requests. You send a GET-request delivering the Longitude and latitude coordinates of your position and the server returns a JSON-object containing data like sunset, sunrise and others.</li></ul><figure><img src=https://projects.arduinocontent.cc/044bf993-bf12-47ae-bbfa-459336dec297.png /><figcaption>Website to control the LED-strip-Arduino</figcaption></figure>The preceding screenshot demonstrates the website that let's you control the LED strips. On the website you can<ul ><li >(de)activate the motion sensors,</li></ul><ul ><li >set the brightness of the LEDs from 0% to 100%,</li></ul><ul ><li >turn the LED strips on for hh hours, mm minutes and ss seconds,</li></ul><ul ><li >turn off the LED strips,</li></ul><ul ><li >chose from several animations and select the LEDs' colors</li></ul>The homepage sends the data to the server using http-requests. The server saves the settings to the MongoDB database and forwards the data to the Arduino. The server and the Arduino are programmed in a way that the Arduino sets itself up whenever you turn it on - after booting the Arduino requests the currently defined animation, brightness and motion sensor status automatically from the server all by itself. You can unplug the Arduino, plug it back in again and be sure that the Arduino continues to operate like it never had been disconnected.<h3 >STEP-BY-STEP INSTRUCTION</h3>The code can be downloaded from my GitHub page (see links below):<ul ><li >The Arduino code that runs on the Wemos D1 mini</li></ul><ul ><li >Arduino libraries: I exported most of the Arduino code to Arduino libraries to keep the code that runs on the Arduino clean and tidy</li></ul><ul ><li >Server/BackEnd_&amp;_FrontEnd_Code</li></ul>1.The Arduino code must be edited before you can upload it to your Arduino-board. Of course, you have to set your own WiFi-password and SSID. After these modifications, upload the code to your Arduino and fire up the Arduino.2. Arduino libraries : You also have to copy my Arduino libraries in the libraries folder of your Arduino IDE installation: in the installation path of your Arduino IDE there should be a folder called 'libraries'. The only thing you have to do is copy my library-folders into this folder. The Arduino IDE recognizes these files automatically - no compiling needed!note: This code is targeted for my Wemos D1 mini, so it is utilizing several ESP8266-libraries. To make the code executable on an Arduino board there are only a few minor modifications to the code required. You have to replace the ESP8266-specific libraries that are used for the WiFi-communication with the libraries that are targeted for the Arduino (e.g. simply replace <code >#include &lt;ESP8266WiFi.h&gt;</code> with <code >#include &lt;WiFi.h&gt;</code>).3.Launch the server: you have to make sure you have installed the required node.js-modules (check the files package.json and server.js). In addition, I exported several functions to modules that both the front-end and back-end use. It is pretty nasty to use the same javascript files in the frontend and backend because node.js exports/imports code differently than you do it in browser-javascript-files. Therefore I used a trick and globally linked the code that is shared by the frontend and backend (npm link). I wrote a script that links the modules for you. All you have to do is run this script: after extracting the downloaded zip-file, run the link_modules.sh script that is in the projects root directory:<pre ><code >$ bash ./link_modules.sh </code></pre>If you're not running a linux-distro, just have a look inside the script and execute the corresponding platform-specific commands.After linking the modules, execute the following commands in the root folder:<pre ><code >$ npm run build $ node server </code></pre>You have to edit the IP-address that the server uses to connect to the Arduino. It is defined in the file ./server/LEDstripRouter.js. Go to the line const ARDUINO_IP = 'http://esp_0b9e2e'; and replace the IP-address with the one of your Arduino. (Acutally, this is completely unnecessary. In the Arduino-code, there's a DNS_NAME defined. Normally, you should be able to access the Arduino at http://d1ledstrip.local:8080/. But due to some inexplicable issues it doesn't work on my local network. Maybe you are lucky and it works for you).

custom Arduino libraries

Schema

Complete code of the node.js back end (server) & front end (React.js)

Arduino Code: LED-strips

Full Stack RESTful MERN LED Strips

Full stack RESTful MERN environment to control an Arduino -> backend: Node/Express + frontend: React + 2 Arduino-powered LED strips.