Control your Raspberry Pi GPIOs from Arduino Cloud using Node.js / Javascript

Push Button

Breadboard 100x160

Diode Led Red 5mm

Raspberry Pi (Any Model)

Arduino IoT Cloud

<html><body>This project shows how to interact with the Raspberry Pi GPIOs from a dashboard created using Arduino Cloud with an application programmed in Node.js. It can serve as an example to create your own applications that require access to RPI GPIOs and that can be ultimately controlled using a dashboard. <h3>The setup</h3>In this project I have used a Raspberry Pi 5 connected to an LED and a push button, both inserted in a breadboard. This is the diagram <figure><img src="https://projects.arduinocontent.cc/0d88cc48-51b2-4db3-b3f6-3bacd5dd507a.png"/><figcaption>Raspberry Pi GPIO setup diagram</figcaption></figure><blockquote>Note: This project should work with any Raspberry Pi version and actually with any Linux-based machine that supports libgpiod. Please, leave your comments if it does not work with your board in order to review it. </blockquote><h3>How to create your project</h3>The process to use this project is very straighforward: <ol><li>Create the Device and Thing in the Arduino Cloud and get the Arduino Cloud API Key </li><li>Set up the Node.js environment </li><li>Develop the Node.js application </li><li>Create the Arduino Cloud dashboard </li><li>Test everything </li></ol><h3>1. Create the Device and Thing in the Arduino Cloud</h3><blockquote>Note: Before getting started, make sure that you have an Arduino Cloud account </blockquote>Create the Device Go to the <a href="https://app.arduino.cc/devices">Devices </a>section of the Arduino IoT Cloud and click on + DEVICE . Select " Any Device" and follow the instructions on the wizard. <blockquote>Note: Save your <code class="code">Device ID </code>and <code class="code">Secret Key </code>as they will be used in your python code. </blockquote>Create the Thing In your recently created device page, go to the Associated Thing section, click on " Create Thing" and rename it. <blockquote>Note: You can also create the Thing from the Things list and associate it later. </blockquote>Create the Variables Add the variables by clicking on the ADD button. At the end of the process, your list of variables should look like this. <figure><img src="https://projects.arduinocontent.cc/2d16bb57-911c-4ee2-a6f8-754be3bad4c8.png"/><figcaption>Arduino Cloud: Thing variables</figcaption></figure><h3>2. Set up your Node.js environment</h3>Now it is time to install the Node.js dependencies in order to use Arduino Cloud. You have a <a href="https://docs.arduino.cc/arduino-cloud/guides/python/">full tutorial </a>that describes the process in detail. It can be summarized as follows: <ol><li>Install GPIOD library in the system </li><li>Install the Node.js GPIOD package </li><li>Install the Node.js Arduino Cloud packages </li></ol>Install GPIOD library in the system First, you have to install library in the system. If you are using Ubuntu or any other Debian-based machine, you can follow these instructions. <pre>sudo apt install gpiod libgpiod2 libgpiod-dev libnode-dev </pre>Install the GPIOD node.js package using NPM Next, you have to install the node package. <pre>npm install --save node-libgpiod node-fetch </pre> <blockquote>Tip: The NPM modules can be installed globally or locally in the working folder. My suggestion is to work in the `js/` folder and install the modules locally there with the instruction above. Once installed, you should see a folder `js/node_modules/`. If you want to install the modules globally, just add `-g` to the command. </blockquote>Install Arduino Cloud Node.js packages To install the Arduino IoT Cloud client library, you only have to do the following: <pre>npm install arduino-iot-js </pre><h3>3. Develop the Node.js application</h3>Use your favourite programming environment and edit the <code class="code">gpio-basic.js </code>file. Create a file called <code class="code">credentials.js </code>inside the <code class="code">js/gpio-basic/ </code>folder with the following content <pre>module.exports = { </pre><pre>	 DEVICE_ID: 'YOUR_DEVICE_ID', </pre><pre>	 SECRET_KEY: 'YOUR_SECRET_KEY' </pre><pre>}; </pre>If you are using a different Raspberry Pi flavour or any other machine, you should check which is the right chipset (in this example we use `gpiochip4`) and which are the lines that you want to use. Then, modify the following lines accordingly: <pre>const GPIOCHIP = 'gpiochip4'; </pre><pre>const LED = 14; // GPIO14, Pin 8 </pre><pre>const BUTTON = 15; // GPIO15, Pin 10 </pre> <blockquote>Note : In the code, make sure that all the variables are global (chip, ledLine, buttonLine, ...). Otherwise, any timed operation will not work properly. This is mainly an important tip if you are going to modify or adapt the code for your own purposes. </blockquote>If you want to learn more about GPIOs, Raspberry Pi and libraries, check the <a href="https://github.com/dbduino-prjs/rpi-arduino-cloud/blob/master/js/gpio-basic/README.md#notes">Annex </a>at the github project. <h3>4. Create the Arduino Cloud dashboard</h3>The dashboard that we are going to build will look like this <figure><img src="https://projects.arduinocontent.cc/22c5f020-2f37-4ed5-9bf2-19a1a5e3903b.png"/><figcaption>GPIO Basic Dashboard</figcaption></figure>There are 2 ways to create the dashboard: 1. Create it manually. Replicate the one shown above following the instructions in <a href="https://docs.arduino.cc/arduino-cloud/cloud-interface/dashboard-widgets/">this guide </a>. <ol><li>The LED widgets should be linked to the variable <code class="code">led </code></li><li>The Value widgets should be linked to the variable <code class="code">test_value </code></li><li>The Button widgets should be linked to the variable <code class="code">button </code></li></ol>2. Clone the one provided by this tutorial following the instructions in this <a href="https://github.com/dbduino-prjs/rpi-arduino-cloud/blob/master/js/gpio-basic/README.md#clone-the-dashboard-using-cloud-cli">Annex </a>of the github project. <h3>5. Test everything</h3>Run your code <pre>~/rpi-arduino-cloud/js$ node ./gpio-basic/gpio-basic.js </pre>You should see the following: <ol><li>Every time push the button, the button widget should be updated </li><li>Every time you change the LED widget in the dashboard, the physical LED should switch to ON or OFF </li><li>The value of test_value should change randomly every 10s and the value updated in the dashboard </li></ol>Enjoy! <blockquote>Note: If you want to have more details about the implementation, the use of libgpiod, etc, check the documentation at the github project . </blockquote> </body></html>