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

The Adafruit Quad AlphaNumeric FeatherWing - Blue is a versatile and compact display module designed for use with the Feather ecosystem of development boards. It features four high-contrast 14-segment blue LED alphanumeric displays which can show letters and numbers, providing a simple and effective way to add a user interface to your projects. This FeatherWing is ideal for creating readouts for clocks, counters, and other devices that require alphanumeric data to be displayed.

• Digital clocks and timers
• Counter displays
• Readouts for sensors and measurements
• User interfaces for settings and menus
• Debugging information for development purposes

• Operating Voltage: 3.3V to 5V
• Display Color: Blue
• Number of Characters: 4
• Character Segments: 14-segment alphanumeric
• Communication: I2C interface
• I2C Addresses: 0x70 (default) - 0x77 (selectable with solder jumpers)

1. Power Connections: Connect the 3V pin to the 3.3V output on your Feather board and GND to ground.
2. I2C Connections: Connect SDA and SCL to the corresponding I2C pins on your Feather board.
3. Optional Reset: The RST pin can be connected to a digital pin on your Feather board if you wish to control the reset function programmatically.

• Ensure that the power supply is within the specified voltage range to prevent damage.
• Use pull-up resistors on the I2C lines if your Feather board does not have them built-in.
• To change the I2C address, solder the address jumpers on the back of the board.
• When stacking multiple FeatherWings, ensure that the I2C addresses are unique.
• Avoid exposing the display to direct sunlight for extended periods to prevent damage.

#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 its I2C address
}

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

• Display Not Lighting Up: Check the power connections and ensure the I2C lines are properly connected.
• Garbled Characters: Ensure that there are no conflicting I2C addresses if using multiple I2C devices.
• Dim Display: Verify that the power supply is adequate and within the specified voltage range.

• Double-check wiring, especially the I2C connections.
• Use the I2C scanner sketch to confirm the display's address is detected by the microcontroller.
• If using multiple FeatherWings, ensure that each has a unique I2C address.
• Consult the Adafruit forums and guides for additional support and resources.

Q: Can I use this display with a 5V system? A: Yes, the display can be used with a 5V system, but ensure that the I2C logic levels are compatible.

Q: How do I change the I2C address? A: Solder the address jumpers on the back of the board to configure the address between 0x70 to 0x77.

Q: Can I use this FeatherWing with other microcontrollers besides Feather boards? A: Yes, as long as the microcontroller supports I2C communication and operates within the voltage range, it can be used with this display.

Q: How do I display numbers and letters? A: Use the writeDigitAscii function to display characters on the display, as shown in the example code.

Q: Is it possible to display special characters? A: The 14-segment display can show a limited set of special characters. Refer to the Adafruit GFX library for supported characters.