> For the complete documentation index, see [llms.txt](https://theiotlearninginitiative.gitbook.io/embedded-linux/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://theiotlearninginitiative.gitbook.io/embedded-linux/application-development/nodejs.md).
# NodeJS
> In software development, Node.js is an open-source, cross-platform runtime environment for developing server-side Web applications. Although Node.js is not a JavaScript framework, many of its basic modules are written in JavaScript, and developers can write new modules in JavaScript. The runtime environment interprets JavaScript using Google's V8 JavaScript engine. [Wikipedia](https://en.wikipedia.org/wiki/Node.js)
* [Principles of Writing Consistent, Idiomatic JavaScript](https://github.com/rwaldron/idiomatic.js)
* [A set of node-red nodes for connecting to johnny-five IO Plugins](https://github.com/monteslu/node-red-contrib-gpio)
* [Intel Galileo & Intel Edison IO Plugin for Johnny-Five](https://github.com/rwaldron/galileo-io/)
* [Debug Node js remotely on Intel Edison with Jetbrains Idea](https://m2aglabs.com/2015/11/04/debug-node-js-remotely-on-intel-edison-with-jetbrains-idea/)
* [Arduino Experimenter's Guide for NodeJS](http://node-ardx.org/)
* [JavaScript: The Perfect Language for the Internet of Things (IoT)](https://blog.jscrambler.com/javascript-the-perfect-language-for-the-internet-of-things-iot/)
* [Node.Js for Embedded Systems](http://embeddednodejs.com/chapters.html)
* [Programming the Internet of Things with Node.Js](http://cdn.oreillystatic.com/en/assets/1/event/127/Programming%20the%20Internet%20of%20Things%20with%20Node_js%20and%20HTML5%20Presentation.pdf)
* [Fast, reliable, and secure dependency management](https://github.com/yarnpkg/yarn)
## Mraa
```bash
root@edison:~# nano mr.js
```
```javascript
var mraa = require('mraa');
var pinDigital = new mraa.Gpio(13);
console.log('MRAA Version: ' + m.getVersion());
pinDigital.dir(mraa.DIR_OUT);
pinDigital.write(1);
```
```bash
root@edison:~# node mr.js
```
## Nodejs, Socket.io and Intel Edison
```bash
root@edison:~# npm install -g express socket.io
-\|/-\|/-\|/-\-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/--\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\|/-\s
��├��─��─ escape-html@1.0.3
��├��─��─ range-parser@1.0.3
...
��├��─��─ socket.io-adapter@0.4.0 (socket.io-parser@2.2.2)
��└��─��─ socket.io-client@1.4.5 (to-array@0.1.4, indexof@0.0.1, component-
root@edison:~# git clone https://github.com/m2aglabs/socket.io-demo.git
Cloning into 'socket.io-demo'...
remote: Counting objects: 22, done.
remote: Total 22 (delta 0), reused 0 (delta 0), pack-reused 22
Unpacking objects: 100% (22/22), done.
Checking connectivity... done.
root@edison:~# cd socket.io-demo/
root@edison:~/socket.io-demo# ls
LICENSE.md icon.png package.json
README.md index.html thermo_demo.xdk
app.js js thermo_demo.xdke
root@edison:~/socket.io-demo# node app.js
MRAA Version: v0.8.0
```
In a web browser go to
## Using a Rotary Encoder on Intel Edison, XDK
* [Rotary Encoder Demo](https://github.com/m2aglabs/rotary_encoder_demo)
Requirements
* Grove Rotary Encoders on D2
* Grove Button on D4
```bash
itot@edison:~# git clone https://github.com/m2aglabs/rotary_encoder_demo.git
Cloning into 'rotary_encoder_demo'...
remote: Counting objects: 25, done.
remote: Total 25 (delta 0), reused 0 (delta 0), pack-reused 25
Unpacking objects: 100% (25/25), done.
Checking connectivity... done.
root@edison:~/trash# cd rotary_encoder_demo/
root@edison:~/trash/rotary_encoder_demo# ls
LICENSE.md index.html rotary_demo.xdk
README.md js rotary_demo.xdke
icon.png package.json server.js
root@edison:~/rotary_encoder_demo# node server.js
MRAA Version: v0.8.0
```
In a web browser go to
## NodeJS Modules
```bash
root@edison:~# ls /usr/lib/node_modules/
iotkit jsupm_grovevdiv jsupm_mpl3115a2
iotkit-agent jsupm_grovewater jsupm_mpr121
iotkit-comm jsupm_grovewfs jsupm_mpu9150
jsupm_a110x jsupm_guvas12d jsupm_mq303a
jsupm_ad8232 jsupm_h3lis331dl jsupm_my9221
jsupm_adafruitms1438 jsupm_hcsr04 jsupm_nrf24l01
jsupm_adafruitss jsupm_hm11 jsupm_nrf8001
jsupm_adc121c021 jsupm_hmc5883l jsupm_nunchuck
jsupm_adis16448 jsupm_hmtrp jsupm_otp538u
jsupm_adxl335 jsupm_hp20x jsupm_pca9685
jsupm_adxl345 jsupm_ht9170 jsupm_pn532
jsupm_am2315 jsupm_htu21d jsupm_ppd42ns
jsupm_apds9002 jsupm_hx711 jsupm_pulsensor
jsupm_at42qt1070 jsupm_i2clcd jsupm_rfr359f
jsupm_biss0001 jsupm_ina132 jsupm_rgbringcoder
jsupm_bmpx8x jsupm_isd1820 jsupm_rotaryencoder
jsupm_buzzer jsupm_itg3200 jsupm_rpr220
jsupm_cjq4435 jsupm_joystick12 jsupm_servo
jsupm_ds1307 jsupm_l298 jsupm_si114x
jsupm_ecs1030 jsupm_ldt0028 jsupm_sm130
jsupm_enc03r jsupm_lm35 jsupm_st7735
jsupm_flex jsupm_lol jsupm_stepmotor
jsupm_gas jsupm_loudness jsupm_sx6119
jsupm_gp2y0a jsupm_lpd8806 jsupm_ta12200
jsupm_grove jsupm_lsm303 jsupm_tcs3414cs
jsupm_grovecircularled jsupm_lsm9ds0 jsupm_th02
jsupm_grovecollision jsupm_m24lr64e jsupm_tm1637
jsupm_groveehr jsupm_max31723 jsupm_tsl2561
jsupm_groveeldriver jsupm_max31855 jsupm_ttp223
jsupm_groveelectromagnet jsupm_max44000 jsupm_ublox6
jsupm_groveemg jsupm_max5487 jsupm_uln200xa
jsupm_grovegprs jsupm_maxds3231m jsupm_waterlevel
jsupm_grovegsr jsupm_maxsonarez jsupm_wheelencoder
jsupm_grovelinefinder jsupm_mg811 jsupm_wt5001
jsupm_grovemd jsupm_mhz16 jsupm_yg1006
jsupm_grovemoisture jsupm_mic jsupm_zfm20
jsupm_groveo2 jsupm_mlx90614 mraa
jsupm_grovescam jsupm_mma7455 npm
jsupm_grovespeaker jsupm_mma7660
root@edison:~#
```
## NodeJS Edison-Cli
```bash
xe1gyq@jessie:~$ sudo npm install -g edison-cli
npm WARN deprecated graceful-fs@3.0.8: graceful-fs v3.0.0 and before will fail on node releases >= v6.0. Please update to graceful-fs@^4.0.0 as soon as possible. Use 'npm ls graceful-fs' to find it in the tree.
> ws@0.4.32 install /usr/local/lib/node_modules/edison-cli/node_modules/ws
> (node-gyp rebuild 2> builderror.log) || (exit 0)
make: Entering directory '/usr/local/lib/node_modules/edison-cli/node_modules/ws/build'
CXX(target) Release/obj.target/bufferutil/src/bufferutil.o
SOLINK_MODULE(target) Release/obj.target/bufferutil.node
SOLINK_MODULE(target) Release/obj.target/bufferutil.node: Finished
COPY Release/bufferutil.node
CXX(target) Release/obj.target/validation/src/validation.o
SOLINK_MODULE(target) Release/obj.target/validation.node
SOLINK_MODULE(target) Release/obj.target/validation.node: Finished
COPY Release/validation.node
make: Leaving directory '/usr/local/lib/node_modules/edison-cli/node_modules/ws/build'
/usr/local/bin/edison-cli -> /usr/local/lib/node_modules/edison-cli/bin/edison-cli
edison-cli@2.0.0 /usr/local/lib/node_modules/edison-cli
├── commander@2.9.0 (graceful-readlink@1.0.1)
├── temporary@0.0.8 (package@1.0.1)
├── mdns-js@0.1.5 (debug@0.8.1)
├── fstream@1.0.8 (inherits@2.0.1, graceful-fs@4.1.3, mkdirp@0.5.1, rimraf@2.5.2)
├── tar-edison@0.1.16 (inherits@1.0.2, block-stream@0.0.8, fstream@0.1.31)
└── ws@0.4.32 (tinycolor@0.0.1, options@0.0.6, commander@2.1.0, nan@1.0.0)
xe1gyq@jessie:~$ edison-cli list
Edison Devices Found: 2
1 - 192.168.1.70
2 - 192.168.1.70
xe1gyq@jessie:~$
```
---
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