SmartMatrix Library for Teensy 3
The SmartMatrix Library is designed to make it easy to display graphics and scrolling text on multiplexed RGB LED matrix panels connected to a Teensy 3.
Version 3.0 is a significant upgrade from 2.x, with a new API that is not backwards compatible. See the release notes on GitHub for more details, and MIGRATION.md for details on migrating sketches from SmartMatrix 2.x to 3.0. You can have SmartMatrix3 installed in parallel with an existing SmartMatrix_32x32 or SmartMatrix_16x32 library without conflicts.
More documentation Here:
To download in Arduino Library form, see Releases on GitHub, or just add the files in the /src directory to your Arduino project.
Software and Teensy Setup
This documentation assumes you have a general knowledge of the Teensy 3.1/3.2, how to use the Arduino IDE, and the Teensyduino addon. If you need an overview of any of those tools, please use these references:
- PJRC - Teensyduino
- Arduino - Getting Started with Arduino
- For general Teensy 3.1/3.2 support, not related to the SmartMatrix Shield or SmartMatrix Library, post a question at the PJRC Forum
Make sure you have a supported version of the Arduino IDE and Teensyduino add-on installed.
Before continuing, use the blink example in the Arduino IDE to verify you can compile and run a sketch on your Teensy 3.1/3.2.
Download the latest version of the SmartMatrix Library:
SmartMatrix Releases - GitHub
Import the library, see instructions from Arduino here:
Arduino - Libraries
Start with the FeatureDemo Example project, included with the library. From the Arduino File menu, choose Examples, SmartMatrix3, then FeatureDemo.
You should already have most of the correct Arduino settings to load the FeatureDemo sketch on your Teensy, from running the blink example earlier. Under Tools, CPU Speed, make sure either 48 MHz or 96MHz (overclock) is selected. (Some libraries are not compatible with the 72MHz CPU)
The examples are configured to run on a 32x32-pixel panel. If your resolution is different, adjust the
kMatrixHeight variables at the top of the sketch. If you are using a 16x32-pixel panel, also change
New with SmartMatrix Library 3.0, you can chain several panels together to create a wider or taller display than one panel would allow. Set
kMatrixHeight to the overall width and height of your display. If your display is more than one panel high, set
kMatrixOptions to how you tiled your panels:
- Panel Order - By default, the first panel of each row starts on the same side, so you need a long ribbon cable to go from the last panel of the previous row to the first panel of the next row.
SMARTMATRIX_OPTIONS_C_SHAPE_STACKINGinverts the panel on each row to minimize the length of the cable going from the last panel of each row the first panel of the other row.
- Panel Direction - By default the first panel is on the top row. To stack panels the other way, use
- To set multiple options, use the bitwise-OR operator e.g. C-shape Bottom-to-top stacking:
const uint8_t kMatrixOptions = (SMARTMATRIX_OPTIONS_C_SHAPE_STACKING | SMARTMATRIX_OPTIONS_BOTTOM_TO_TOP_STACKING);
Click the Upload button, and the sketch should compile and upload to your Teensy, and start running right away.
You can use the FeatureDemo sketch as a way to get started with your own project. Inside
loop(), find a demo section that is similar to what you want to do with your project, delete the other sections, and save it as as new sketch.
Some SmartMatrix examples require external libraries to compile. You may already have older versions of these libraries installed in Arduino that may be too old to work with SmartMatrix and the examples.
Installing Arduino libraries from GitHub has a couple pitfalls. This Adafruit tutorial explains the basics of installing libraries and how to avoid the pitfalls.
If you're having trouble compiling Aurora and are getting errors that refer to FastLED.h, try compiling the
FastLED_Functions example first, which will help narrow down the issue. Also make sure you are using FastLED 3.1 or later.
This error means the FastLED library isn't installed (correctly):
fatal error: FastLED.h: No such file or directory
The FastLED version included with Teensyduino may lag behind the latest. It's better to install FastLED manually using the latest version available from GitHub. If you see any of these errors, you likely have an older version of FastLED installed:
no known conversion for argument 4 from 'CRGB' to 'const rgb24&'
error: 'inoise8' was not declared in this scope
This can be tricky to track down as Teensyduino installs libraries into your Arduino application directory, which might not be in your Arduino sketchbook. For OSX you will need to navigate into the the Arduino.app package to find the libraries folder and delete the old FastLED.
Install the latest version of FastLED (3.x or higher) from the FastLED releases page: https://github.com/FastLED/FastLED/releases
Teensy Audio Library
The SpectrumAnalyzer sketch requires the Teensy Audio Library, which is included in Teensyduino. If you have trouble compiling, first make sure you can compile either the FastLED example, as FastLED 3.x is also a requirement for this sketch. If you're missing the Audio library, the best way to install is by running the Teensyduino installer. Make sure the "Audio" library is checked during the install, but don't check all libraries as you might downgrade FastLED.