How to Use Adafruit 8x16 LED Matrix FeatherWing - Yellow: Examples, Pinouts, and Specs

The Adafruit 8x16 LED Matrix FeatherWing - Yellow is a versatile and compact LED matrix display designed for integration with the Adafruit Feather series of development boards. This expansion board features a grid of 8x16 individually addressable yellow LEDs, allowing for a wide range of visual output possibilities. It is commonly used for creating scrolling text displays, simple animations, and other visual indicators in portable projects.

• Wearable electronics
• Portable message displays
• Data visualization for sensors
• User interfaces for projects
• Educational tools for learning programming and electronics

• LED Color: Yellow
• Matrix Size: 8x16 LEDs
• Communication: I2C interface
• Operating Voltage: 3.3V to 5V (Feather compatible)
• Dimensions: 51mm x 23mm x 4.6mm / 2.0" x 0.9" x 0.18"
• Weight: 4.8 grams

1. Power Connection: Connect the 3V pin to the 3.3V output on your Feather board and GND to ground.
2. I2C Connection: Connect SDA and SCL pins to the corresponding I2C pins on your Feather board.
3. Address Selection (Optional): If using multiple LED matrices, you can set different I2C addresses by connecting the ADDR pin to ground or 3V.
4. Reset (Optional): The RST pin can be connected to a digital pin on your Feather board to allow software reset of the LED matrix.

• Ensure that your Feather board can supply enough current for the LED matrix.
• When using multiple matrices, verify that the total current does not exceed the power supply capabilities.
• Avoid looking directly at the LEDs for extended periods to prevent eye strain or damage.

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_LEDBackpack.h>

Adafruit_8x16matrix matrix = Adafruit_8x16matrix();

void setup() {
  matrix.begin(0x70); // Initialize the matrix with its I2C address
  matrix.setBrightness(10); // Set the brightness to a medium level
  matrix.clear(); // Clear the matrix display
}

void loop() {
  matrix.clear(); // Clear the matrix display
  matrix.setCursor(0, 0); // Set cursor at top-left corner
  matrix.print(F("Hello")); // Print a message to the matrix
  matrix.writeDisplay(); // Update the display with the new data
  delay(2000); // Wait for 2 seconds
  matrix.scrollLeft(); // Scroll the message to the left
  matrix.writeDisplay(); // Update the display with the new data
  delay(200); // Wait for 200 milliseconds
}

• LEDs Not Lighting Up: Ensure that the power and I2C connections are secure and correct. Check that the Feather board is powered on.
• Garbled Display Output: Verify that the I2C address is correctly set and that there are no conflicts with other I2C devices.
• Dim LEDs: Increase the brightness setting in your code or check the power supply for adequate current.

• Double-check wiring connections and solder joints for any loose connections or shorts.
• Use the i2cdetect utility or similar tools to confirm the I2C address of the LED matrix.
• Ensure that the library and board definitions are up to date in your development environment.

Q: Can I use this LED matrix with boards other than Feather? A: Yes, as long as the board supports I2C communication and operates within the voltage range.

Q: How do I chain multiple LED matrices together? A: You can chain multiple matrices by connecting their I2C lines in parallel and setting unique I2C addresses for each matrix.

Q: Can I display images on the LED matrix? A: Yes, you can display bitmap images, but they need to be formatted for the 8x16 resolution and converted into the appropriate format for the Adafruit GFX library.

Q: Is it possible to use this LED matrix with a 5V system? A: The matrix is designed to be 5V tolerant on the I2C lines, but it is recommended to use a level shifter for reliable operation.