sparkfun DEV-15046 User manual

Getting Started with the SmartLED Shield for Teensy
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Introduction
The PixelMatix SmartLED shield for Teensy makes it easy to connect to RGB LED matrix panels! The shield
makes it easy to connect to the 16 pins required to drive the display, connects an external 5V supply to power the
display and Teensy, and brings out the Teensy’s free signals to a convenient header.
In this tutorial, we will explore a some of the examples provided with the SmartLED shield using different RGB
LED matrix panel sizes.
SmartLED Shield V4 for Teensy
 DEV-15046

Required Materials
To follow along with this tutorial, you will need the following materials. You may not need everything though
depending on what you have. Add it to your cart, read through the guide, and adjust the cart as necessary.
RGB LED Matrix Panel - 32x32
 COM-14646
RGB LED Matrix Panel - 32x64
 COM-14718
RGB LED Matrix Panel - 64x64
 COM-14824
Teensy 3.2
 DEV-13736
Teensy 3.6 (Headers)
 DEV-14058

Tools
Depending on your setup, you may need pliers, a soldering iron, solder, and general soldering accessories.
Teensy 3.5
 DEV-14055
Break Away Headers - Straight
 PRT-00116
microSD Card with Adapter - 16GB (Class 10)
 COM-13833
USB micro-B Cable - 6 Foot
 CAB-10215
Teensy 3.5 (Headers)
 DEV-14056
microSD USB Reader
 COM-13004

Suggested Reading
If you aren’t familiar with the following concepts, we recommend checking out these tutorials before continuing.
Solder Lead Free - 100-gram Spool
 TOL-09325
Weller WLC100 Soldering Station
 TOL-14228
Needle Nose Pliers
 TOL-08793
How to Power a Project
A tutorial to help figure out the power requirements of
your project.
What is an Arduino?
What is this 'Arduino' thing anyway?

Hardware Overview
Teensy Footprint
The SmartLED shield makes it easy to connect to RGB LED matrix panels. As opposed to wiring to 16 pins on the
RGB LED matrix panel, you simply sandwich the shield between a Teensy and the IDC connector! The top of the
board is where you would insert the Teensy populated with straight headers. The bottom of the shield includes
female headers to make a secure connection.
Teensy Footprint (Top View) Teensy Footprint (Bottom View)
Adjacent to the Teensy footprint are additional pins that are broken out for easy access for prototyping or soldering
wires directly to the shield.
RGB Panel Hookup Guide
Make bright, colorful displays using the 32x16, 32x32,
and 32x64 RGB LED matrix panels. This hookup guide
shows how to hook up these panels and control them
with an Arduino.
Getting Started with the Teensy
Basic intro to the Teensy line of products, with
soldering and programming suggestions.

Teensy Pins Broken Out (Top View) Teensy Pins Broken Out (Bottom View)
For more information about the reserved pins on the SmartLED matrix shield, check out the image below for the
pins that are used to drive the RGB LED matrix panel and APA102 LEDs.
Image Courtesy of PJRC and PixelMatix
📌 Tip: If you are prototyping with the shield, try grabbing some square header pins, jumper wires, and a
breadboard to connect. Make sure that the jumper wires are square pins for a secure connection with the
female header populated on the bottom of the SmartLED shield.
Jumper Wires Premium 6" M/F Pack of 10
 PRT-09140
Jumper Wires Premium 6" M/M Pack of 10
 PRT-08431

IDC Connector
The shield breaks out the RGB LED matrix panel's IDC pins. Simply align the silkscreen with the panel's input and
stack it on like a backpack. As an alternative, you can use an IDC cable and the included 2x8 long, centered
header pins. Just make sure to align the cable’s red wire with the silkscreen labeled RED WIRE.
IDC Connector (Top View) IDC Connector (Bottom View)
APA102 LED
The shield includes additional 4-pin JST SM connector pair to connect a strip or matrix of APA102 LEDs from the
SmartLED Shield.
Breadboard - Mini Modular (Red)
 PRT-12044
Break Away Headers - 40-pin Male (Long
Centered, PTH, 0.1")
 PRT-12693

Removable Mounting Holes
The shield includes mounting holes by each corner of the board. They can be used to to mount the shield when
using the IDC cable. They are held to the rest of the board with mouse bites. Each of the mounting holes can be
removed using pliers. The image below shows highlights the mounting holes with red lines along the mousebites.
📌 Tip: If you are using a Teensy 3.5/3.6 with straight headers populated beyond the 1x14 pins along the side
of a Teensy, you will need to snap off the mounting hole below pin 13.
ADDX Pins and Logic Levels

Certain panels may require 5V logic levels, which may not be enough with the Teensy's output pins. While you
can try to wire all 16 pins from the Teensy to the IDC cable, it is not the most reliable connection. The panel may
flicker or fail to display properly. The SmartLED shield was designed to include level shifting buffers to safely and
reliably control the RGB LED matrix panels.
Hardware Assembly
If you have not already, solder the male header pins on your Teensy before connecting. We will be using the 1x14
header pins on each side of a Teensy but you can also solder additional pins or or wires depending on your setup.
After soldering and removing the flux from a Teensy, stack the Teensy on the SmartLED shield. Make sure to face
the USB connector in the same direction as the 4-pin JST SM connector.
Align the IDC connector breakout on the SmartLED shield with the IDC connector on your RGB LED Matrix Panel.
The location of the IDC connector depends on the manufacturer of the panel but usually it will be located on the
left side relative to the arrows pointing up and toward the right.

Tip: If you received a shield with the 2x8 header pins installed and decide to add the shield to the RGB LED
matrix panel's IDC connector as a backpack, you can remove the headers from the shield. Otherwise, you
can leave the 2x8 header pins inserted and connect using the IDC cable.
If you have not already, attach a 5V power supply to your RGB LED matrix panel's power cable by using the power
supply in conjunction with a female barrel jack adapter and screwdriver to get a quick and dirty connection
between the spade and barrel jack.
The connection should look like the image below.

Then slide the polarized power cable for the RGB matrix panel into its respective mating connector. The red wires
should be connected to the 5V pins while the black wires should be connected to the GND pins.
For the scope of this tutorial, we will connect 5V USB power directly to the Teensy's USB connector. This is
separate from the power supply that is powering the RGB LED matrix panel. Depending on your setup, you can
use the same power supply that the RGB LED matrix panel is using by connecting to either the Teensy's V+ and
GND pins or the APA102 JST SM connector. Just make sure that the voltage is regulated at 5V.
Once connected, the back of your RGB LED matrix panel should look similar to the images below. On the left, a
Teensy 3.2 was connected to a 64x64 panel with 3mm pitched LEDs. On the right, a Teensy 3.6 was used for a
32x32 with 6mm pitched LEDs.

Alternative Connections
There is an option to daisy chain the panels together if you are within the limits of the SmartLED library. Simply
connect the output from the first panel to the input of the second panel. Make sure to provide power to each panel
through the 4-pin polarized connector.
As explained earlier, you can try to wire all 16 pins from the Teensy to the panel's IDC cable. It is not the most
reliable connection. There is a higher probability of wiring incorrectly or a connection becoming loose. For more
information on trying the connection, check out the table below. This connection is not possible when wiring to a
64x64 panel due to the extra 5th addressing pin.
Panel Pin Label Cable Connector Pin # Teensy Notes
R0 1 2 Red Data
(columns 1-16)
G0 2 5 Green Data
(columns 1-16)
B0 3 6 Blue Data
(columns 1-16)
GND 4 GND Ground
R1 5 21 Red Data
(columns 17-32)

G1 6 8 Green Data
(columns 17-32)
B1 7 20 Blue Data
(columns 17-32)
GND 8 GND Ground
A 9 15 Demux Input A0
B 10 22 Demux Input A1
C 11 23 Demux Input A2
D 12 9 Demux Input E1, E3 (32x32 panels only)
CLK 13 14 LED Drivers' Clock
STB 14 3, 8 LED Drivers' Latch
OE 15 4 LED Drivers' Output Enable
GND 16 GND Ground
Heads up! When manually wiring the board to the panel, make sure that the latch pin is connected to both
pins 3 and 8 on the Teensy! Doesn't the SmartLED shield sound good right about now?
Image courtesy of PixelMatix: Manually Connecting Teensy and Panel
Software Installation

Note: This example assumes you are using the latest version of the Arduino IDE on your desktop. If this is
your first time using Arduino, please review our tutorial on installing the Arduino IDE. If you have not
previously installed an Arduino library, please check out our installation guide.
Teensyduino Add-On
If you haven’t used Teensy before, you’ll need to download and install the extension for the Arduino IDE called
Teensyduino from PJRC. This will also install the drivers for the board. Follow the instructions on installing the add-
on before continuing on.
PJRC: TEENSYDUINO DOWNLOAD PAGE
Install Library
Louis Beaudoin has written an amazing library to control the RGB LED matrix panels. You can obtain these
libraries through the Arduino Library Manager. Search for SmartMatrix3 and you should be able to install the
latest version. If you prefer downloading the libraries manually you can also grab them from the GitHub repository:
GITHUB PIXELMATIX - SMARTMATRIX (ZIP)
Library Overview
For an overview of the functions, check out documentation in the MIGRATION.md file from the GitHub repository.
GITHUBPIXELMATIX DOCS - SMARTMATRIX LIBRARY OVERVIEW
Example: Feature Demo!
There are a few examples from the SmartMatrix library for the SmartLED Shield. For the scope of the tutorial, we
will be highlighting three of the examples.
Feature Demo!
Let's start with the feature demo. After installing the library, click File > Examples > SmartMatrix3 >
FeatureDemo.ino in the Arduino IDE. Once open, there are a minimum of 4 lines to modify to get the example
working with your matrix panel:
uncomment line “ #include <SmartLEDShieldV4.h> ” if you are using the shield
adjust kMatrixWidth to the width of your panel
adjust kMatrixHeight to the height of your panel
adjust kPanelType based on the scan rate of your panel from line 34 in SmartMatrix3.h
The comments in the example code indicate that he known working width are: “32, 64, 96, 128”. As for the height,
the known working sizes are: 16, 32, 48, 64. If you dig into the library, the known working scan rates are 1:8, 1:16,
and 1:32.
64x64 Panel with 1/32 Scan Rate
Let's try modifying the example code to work with the 64x64 panel with a 1/32 scan rate. The SmartLED shield is
required to address the extra 5th ADDX pin on the IDC connector. Simply:

uncomment line “ #include <SmartLEDShieldV4.h> ” by removing the “ // ”
adjust kMatrixWidth to the width of your panel by replacing 32 with 64
adjust kMatrixHeight to the height of your panel by replacing 32 with 64
adjust kPanelType by replacing SMARTMATRIX_HUB75_32ROW_MOD16SCAN with
SMARTMATRIX_HUB75_64ROW_MOD32SCAN from line 34 in SmartMatrix3.h
When the changes are completed, select the Teensy board definition with the associated COM port and click
upload. You should see the feature demo running. This includes scrolling text, animations, shapes being drawn,
brightness changing, and refresh rate changing.
Daisy Chained 32x64 with 1:16 Scan Rate
Let's try modifying the example code to work with two 32x64 panels with a 1:16 scan rate. In this example, we
manually wire the connection to a Teensy 3.2. Modify the original code by:
leaving the line “ #include <SmartLEDShieldV4.h> ” commented out by using the “ // ”
adjusting kMatrixWidth to the width of your panel by replacing 32 with 128
keeping kMatrixHeight the height of your panel by leaving 32 at 32
keeping kPanelType by leaving SMARTMATRIX_HUB75_32ROW_MOD16SCAN at
SMARTMATRIX_HUB75_32ROW_MOD16SCAN from line 34 in SmartMatrix3.h
When the changes are completed, select the Teensy board definition with the associated COM port and click
upload. You should see the same demo running but for a matrix size of 32x128!
Resources and Going Further
Now that you’ve successfully got your SmartLED shield for Teensy up and running, it’s time to incorporate it into
your own project!

For more information, check out the resources below:
Pixelmatix
Hackster.io: SmartMatrix Projects
TeensyDuino
GitHub: PixelMatix
SmartMatrix Library
Need some inspiration for your next project? Check out some of these related tutorials:
Maybe try making a hover pong game with the 32x32 RGB LED Matrix using a gesture sensor and the SmartLED
Shield. The example code can be found in the GitHub repo HoverPong.
Or check out the Aurora project.
Instructables: SmartMatrix - Dynamic LED Art Display
GitHub PixelMatix: Aurora Project
RGB Panel Jumbotron
This tutorial will show you how to combine a webcam, a
32x32 RGB LED panel, and a Teensy 3.1 to stream
video from the webcam, pixelate it, and display it on the
LED panel - LIVE.
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