How to Use Adafruit Quad AlphaNumeric Featherwing - Pure Green: Examples, Pinouts, and Specs

The Adafruit Quad AlphaNumeric Featherwing is a versatile and easy-to-use LED matrix display board that is designed to work with the Feather ecosystem. It features four 14-segment alphanumeric displays capable of showing text, numbers, and symbols in a bright pure green color. This component is ideal for adding a user interface to projects without the need for a full graphical display, making it perfect for time displays, counters, and readouts in various electronics projects.

• Clocks and timers
• Counter displays
• Scoreboards
• Message boards
• Data monitoring displays

• Operating Voltage: 3.3V to 5V
• Current Draw: 80mA (typical, with all segments lit)
• Display Color: Pure Green
• Number of Characters: 4
• Character Height: 0.54 inches
• Communication: I2C interface

1. Powering the Display:

   • Connect the VCC pin to a 3.3V or 5V power supply.
   • Connect the GND pin to the ground of the power supply.

2. Interfacing with a Microcontroller:

   • Connect the SDA and SCL pins to the I2C data and clock lines of your microcontroller, respectively.
   • If necessary, connect the RST pin to a digital output on your microcontroller for resetting the display.

3. Programming the Display:

   • Use the Adafruit LED Backpack library to control the display via I2C.
   • Initialize the display and set the brightness as needed.

• Ensure that the power supply voltage does not exceed the maximum rating of 5V.
• When displaying static text for extended periods, consider using a lower brightness setting to prolong the life of the LEDs.
• Use pull-up resistors on the I2C lines if they are not already present on the microcontroller board.
• Avoid exposing the display to mechanical stress or extreme temperatures.

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

Adafruit_AlphaNum4 alpha4 = Adafruit_AlphaNum4();

void setup() {
  alpha4.begin(0x70);  // Initialize the display with the I2C address 0x70
  alpha4.setBrightness(10);  // Set the display brightness (0 is dimmest, 15 is brightest)
}

void loop() {
  alpha4.writeDigitAscii(0, 'A');  // Display 'A' on the first character position
  alpha4.writeDigitAscii(1, 'd');  // Display 'd' on the second character position
  alpha4.writeDigitAscii(2, 'a');  // Display 'a' on the third character position
  alpha4.writeDigitAscii(3, 'F');  // Display 'F' on the fourth character position
  alpha4.writeDisplay();           // Send the data to the display to actually show it
  delay(1000);                     // Wait for a second
  alpha4.clear();                  // Clear the display
  alpha4.writeDisplay();           // Update the display to show the clear
  delay(1000);                     // Wait for a second
}

• Display Not Lighting Up:

  • Check the power connections to ensure the display is properly powered.
  • Verify that the I2C address used in the code matches the address of the display.
  • Ensure that the I2C lines are connected correctly and that pull-up resistors are in place if needed.

• Characters Not Displaying Correctly:

  • Check for any loose connections or soldering issues.
  • Make sure the correct characters are being sent in the code.
  • Verify that the library and code are compatible with the display.

• Use the i2cdetect tool or similar to confirm that the display is detected on the I2C bus.
• If using multiple I2C devices, ensure that there are no address conflicts.
• Check the Arduino serial monitor for any error messages or debug information.
• Review the Adafruit LED Backpack library documentation for additional functions and examples.

Q: Can I use this display with a 5V microcontroller like the Arduino UNO? A: Yes, the display can be used with both 3.3V and 5V microcontrollers.

Q: How do I change the I2C address of the display? A: The I2C address can be changed by soldering the address jumpers on the back of the PCB. Refer to the Adafruit guide for the specific jumper settings.

Q: Can I daisy-chain multiple displays together? A: Yes, multiple displays can be connected in series via the I2C bus, with unique addresses set for each display.

Q: Is it possible to display custom characters or symbols? A: Yes, the display supports custom characters and symbols by setting individual segments. Refer to the Adafruit GFX library for creating custom characters.