# Arduino LED Hello World

**URL:** <https://discourse.processing.org/t/arduino-led-hello-world/819>\
**Category:** Coding Questions\
**Created:** [June 9, 2018, 10:01pm UTC](https://discourse.processing.org/t/arduino-led-hello-world/819 "2018-06-09T22:01:22Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Onsgaannoubraai](https://avatars.discourse-cdn.com/v4/letter/o/cab0a1/32.png) [@Onsgaannoubraai](https://discourse.processing.org/u/Onsgaannoubraai)\
**Post date:** [June 9, 2018, 10:01pm UTC](https://discourse.processing.org/t/arduino-led-hello-world/819/1 "2018-06-09T22:01:22Z")

</div>

_Beginner to P5js and Arduinos._

Trying to setup a [LED on the Arduino](https://github.com/sarahgp/p5bots) (windows machine + dont have a rgb LED) to blink on arrow key press for the Hello World setup. Using the example files I have commented in the LED on and off section within the quicktest.js file so as to avoid the rgb LED example in the diagrams.

Launched the p5js-server example file using the command line example in the hello world “[bots-go -d](https://github.com/sarahgp/p5bots/blob/master/examples/HelloWorld.md)”. Cant get past an error saying: “sp is not defined”

```auto
C:\Users\username>bots-go -d D:\Username\Projects\Processing\p5js\helloWorld
server starting
connected
connected
C:\Users\username\AppData\Roaming\npm\node_modules\p5bots-server\lib\serial.js:50
    sp.list(function (err, ports) {
    ^

ReferenceError: sp is not defined
    at Socket.<anonymous> (C:\Users\usernmae\AppData\Roaming\npm\node_modules\p5bots-server\lib\serial.js:50:5)
    at emitNone (events.js:106:13)
    at Socket.emit (events.js:208:7)
    at C:\Users\username\AppData\Roaming\npm\node_modules\p5bots-server\node_modules\socket.io\lib\socket.js:503:12
    at _combinedTickCallback (internal/process/next_tick.js:131:7)
    at process._tickCallback (internal/process/next_tick.js:180:9)

```

not sure how it relates as I have not changed anything there?  
Thanks for your time ☀