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

The Adafruit 8x16 LED Matrix FeatherWing - Yellow-Green (Manufacturer Part ID: 3154) is a compact and versatile LED matrix display module. It features 128 yellow-green LEDs arranged in an 8x16 grid, making it ideal for creating visual outputs such as scrolling text, animations, or status indicators. Designed specifically for use with Adafruit Feather boards, this FeatherWing simplifies integration into projects by providing a plug-and-play solution for adding a bright and dynamic display.

• Scrolling text displays
• Visual indicators for IoT projects
• Animations and graphics for creative projects
• Debugging or status monitoring in embedded systems
• Educational and prototyping purposes

The following table outlines the key technical details of the Adafruit 8x16 LED Matrix FeatherWing:

The FeatherWing connects directly to Adafruit Feather boards via the Feather header pins. Below is a description of the key pins used:

1. Attach the FeatherWing to a Feather Board: Align the FeatherWing with the Feather board's headers and press it into place. Ensure proper orientation.
2. Power the Feather Board: The FeatherWing draws power directly from the Feather board, so no additional power supply is needed.
3. Install Required Libraries: Download and install the Adafruit HT16K33 library for Arduino from the Arduino Library Manager.
4. Write and Upload Code: Use the provided example code or write your own to control the LED matrix.

• I2C Address Configuration: If using multiple FeatherWings, configure unique I2C addresses by adjusting the solder jumpers on the back of the board.
• Brightness Control: The brightness of the LEDs can be adjusted programmatically using the library.
• Avoid Overloading the Feather Board: Ensure the Feather board can supply sufficient current for the LEDs, especially if other peripherals are connected.
• Secure Connections: Use standoffs or other mounting hardware to secure the FeatherWing to the Feather board for reliable operation.

Below is an example of how to display scrolling text on the LED matrix using an Adafruit Feather board:

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

// Create an instance of the LED matrix object
Adafruit_8x16matrix matrix = Adafruit_8x16matrix();

void setup() {
  // Initialize the LED matrix
  matrix.begin(0x70); // Default I2C address is 0x70

  // Set brightness (0 = dimmest, 15 = brightest)
  matrix.setBrightness(10);

  // Clear the display
  matrix.clear();
  matrix.writeDisplay();
}

void loop() {
  // Display scrolling text
  matrix.clear();
  matrix.setTextSize(1);       // Set text size to 1
  matrix.setTextColor(LED_ON); // Turn on LEDs for text
  matrix.setCursor(0, 0);      // Start text at the top-left corner
  matrix.print("Hello!");      // Text to display

  // Scroll the text across the display
  for (int i = 0; i < 16; i++) {
    matrix.scrollDisplayLeft(); // Scroll text to the left
    matrix.writeDisplay();      // Update the display
    delay(100);                 // Delay for smooth scrolling
  }
}

1. LED Matrix Not Lighting Up:

   • Ensure the FeatherWing is properly seated on the Feather board.
   • Verify that the Feather board is powered and running the correct code.
   • Check the I2C connections (SDA and SCL) for continuity.

2. Incorrect or No Text Display:

   • Confirm that the correct I2C address (0x70 by default) is being used in the code.
   • Check for solder bridges or incorrect configurations on the I2C address jumpers.

3. Dim LEDs or Flickering:

   • Ensure the Feather board is supplying sufficient power.
   • Reduce the brightness setting in the code if necessary.

4. Multiple FeatherWings Not Working:

   • Verify that each FeatherWing has a unique I2C address by adjusting the solder jumpers.

Q: Can I use this FeatherWing with non-Adafruit boards?
A: Yes, as long as the board supports I2C communication and provides 3.3V or 5V power, you can use this FeatherWing. However, you may need to wire it manually.

Q: How do I change the I2C address?
A: Adjust the solder jumpers on the back of the FeatherWing. Refer to the silkscreen markings for the correct configuration.

Q: Can I chain multiple FeatherWings together?
A: Yes, up to four FeatherWings can be chained by assigning unique I2C addresses to each.

Q: Is the brightness adjustable?
A: Yes, the brightness can be adjusted programmatically using the Adafruit HT16K33 library.

This concludes the documentation for the Adafruit 8x16 LED Matrix FeatherWing - Yellow-Green. For further assistance, refer to the official Adafruit product page or support forums.