Introduction: Scroll a Message on a LED Matrix
If you have a shop or an office or even your home and want to display a scrolling message to tell the happy hours, the weather or any information of your choice, here is the instructable!
It uses a TimeSquAir (http://TimeSquAir.io) a all in one Raspberry Pi bundled with a LED Matrix and a NFC tag, easily customizable with a graphical UI powered by IBM's Node-RED (http://Nore-RED.org).
We'll see how to scroll a fixed message first, then a internet fetched one (the Bitcoin value).
Here is the result (video):
Step 1:
Step 2: Access the Pi From Your Browser
Enter the network address of the Pi into the address bar of your browser (see here for details).
You get IBM's Node-RED graphical interface that will allow us to customize the TimeSquAir behavior by just drag'n dropping some elements from the left palette:
Step 3: Build the LED Matrix Flow
Now you can use the provided nodes for the LEDMatrix bundled in TimeSquAir:
Step 4: Build the Message
You can link these elements (called "nodes") to build the message.
First use a LED Blank node to start. Then use a mix of LED Text and LED Picture nodes to compose the message. End with a LED Matrix node and use a Go node to activate the whole.
To display a simple text, a LED Text node is enough:
Step 5:
You can do more by mixing text and pictures:
Step 6:
Of course, some value may not be known at this time, thus should be calculated at runtime.
The solution is to use a function node and calculate the value in javascript (an easy to use software language).
Step 7: Using Calculated Values
Let it more useful and go fetch the bitcoin value on the web.
We get the value by making an HTTP request to https://paymium.com/api/v1/data/eur/ticker.
You can get mode detail here: http://thethingbox.io/docs/LEDMatrix.html.
Here is the final flow:
Step 8:
Step 9: Learn More !
Learn how to link things together with TimeSquAir (http://TimeSquAir.io) and IBM's Node-RED (http://nodered.org)
and discover the other Instructables:
