(watch it in action)

An application for live-coding some LEDs in the Recurse Center space.

The application has three components:

• Javascript client: for sending websocket data for lights
• A server on a teensy board for handling websocket connection and powering lights
• A Node.js server for persisting user code to a MongoDB database

There is an additional branch called simulator which has a 3D simulator written in THREE.js that you can access online at thundertube.now.sh. (Maintained by @strickinato)

It's all run on a raspberry pi on the Recurse LAN. ([email protected])

This can be done either on your own machine or on the raspberry pi. Note that if you run it on your own machine, the UI may complain about not being able to connect to the web socket.

1. Follow instructions at https://docs.mongodb.com to install MongoDB.
2. Run the following to start a local MongoDB instance on port 39700, storing data in ~/data/thunderbird/db:

$ mkdir -p ~/data/thundertube/db
$ mongod --port 39700 --dbpath ~/data/thunderbird/db

3. In this project repository, add the file server/databaseconfig.js with the following contents:

exports.DatabaseConfig = {PATH: 'mongodb://127.0.0.1:39700'};

Then follow the instructions below to run the server.

WARNING: If you do this, changes you make (and bugs you introduce) in your local server will reflect on the raspberry pi.

1. Follow instructions at https://docs.mongodb.com to install MongoDB.
2. If necessary, copy the server/databaseconfig.js file from the raspberry pi to your version of the repository. Ensure that this file is not checked into source control since it contains the username/password of the live database.

Then follow the instructions below to run the server.

Once the server/databaseconfig.js file exists and points to a MongoDB database, you can run the server:

$ npm install
$ npm start
Listening on port 5000...
Attempting to connect to database at: mongodb://127.0.0.1:39700
Successfully connected to database.

Then you can access the UI at http://localhost:5000.

The client uses code mirror for the editor. For the client dependencies, we don't use a build script and instead they're directly referenced from the the source code in client/lib directory. See the index.html for how they're included.

The hardware is a prototype of Max D's (F2'18) LEDRiver project - which is based around a Teensy3.2 board.

(Done on Mac v10.13.16)

Install the arduino editor. Then install the teensy extension

Go to Tools → Manage Libraries, then search for and install SSD1306Ascii Then, in /Applications/Arduino.app/Contents/Java/libraries/, delete Ethernet/ and SD/

Install the following in ~/Documents/Arduino/libraries/:

• https://github.com/chrisstaite/TeensyDmx
• https://github.com/brandenhall/Arduino-Websocket
• https://github.com/bblanchon/ArduinoJson
• https://github.com/sstaub/TeensyID

Now open the Arduino IDE, and select Tools → Board → "Teensy 3.2"

• There are many modes. A button on the side controls what mode we're in. Thundertube expects "websocket control mode"!
• Try unplugging and plugging back in!
• Make sure the Node.js server is talking to the database you think it's talking to.

The server exposes two HTTP POST endpoints:

• /loadallcodes which queries the database for all user codes and returns them as JSON in the response.
• /saveallcodes which receives all user codes as JSON in the request and writes them to the database. The response contains whether the write was successful.

The raspberry pi by default has LXDE, a linux distro that is heavily built around the Desktop Manager Open Box. In order to set it up to launch our page right away, we took some of the following common raspberry pi steps.

• alt+f4 - close window
• alt+ctrl+f1 - jump out of Desktop Manager to TTY
• Right click on things - the context menus are great

You should be able to find this Raspberry Pi on the Recurse Network. It's called thundertube This is done by simply editing /etc/hostname.

This means you can SSH into the pi if you're on the Recurse Center network. Use ssh [email protected] The password for the pi user is the same as the password for the Recurse Center network.

Enabling SSH on raspberry pi's can be done by adding a file named ssh to the root directory.

As soon as the raspberry pi boots, it should launch our page. This is accomplished by running our startup script

1. sudo raspi-config > Boot Options > Desktop / CLI > Desktop AutoLogin
2. Edit ~/.config/lxsession/LXDE/autostart

# These prevent screen from turning off
@xset s off
@xset -dpms
@xset s noblank
/home/pi/thundertube/startup.sh