Gadgeteer LED Matrix Module Demo

Quick demo of the new (NOTE: this module only works with .NET Micro Framework 4.2, and the driver is still in beta at the time of this writing) LED Matrix module for .NET Gadgeteer, manufactured by GHI Electronics. The module, which is based on the DaisyLink protocol, and contains its own microprocessor (which can be flashed and reprogrammed, if desired) provides an 8x8 matrix of red LEDs for displaying patterns or glyphs.

In this video, I am using a helper class I wrote to display "HELLO WORLD". The driver for the module exposes a single API, DrawBitmap, which takes as an argument a byte array representing the on/off pattern for the LEDs. To make working with the module simpler, I wrote a class with a series of static properties that return the byte array for the uppercase English letters A-Z and numbers 0-9.

To generate the byte arrays required for each letter, I wrote up a quick and dirty HTML and JavaScript utility that displays an 8x8 array of checkboxes, which you can use to create the desired glyph, and which automatically provides the correctly-formatted byte array for use with the LED Matrix module.

With my helper class, I simply create an ArrayList of the letters I want to display, then loop through the ArrayList, displaying each letter in turn. I've named the letters using the NATO phonetic alphabet to make the API intuitive without using single letter property names.

Links:

• GHI's LED Matrix Module
• Alphabet Helper Class code on TinyCLR Codeshare
• Helper Class discussion thread
• HTML/JavaScript 8x8 glyph generator for LED Matrix Module