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

The Adafruit Quad AlphaNumeric FeatherWing is a versatile and compact display module that features four high-contrast red 14-segment alphanumeric LED displays. This component is specifically designed to stack on top of any Adafruit Feather board, providing a convenient and easy-to-read output for displaying data such as time, sensor readings, or custom messages. The use of an I2C interface allows for minimal pin usage and straightforward communication with a microcontroller.

• Digital clocks and timers
• Counter displays
• Readouts for sensors and instruments
• User interfaces for projects
• Message boards and signage

• Operating Voltage: 3.3V to 5V
• Display Color: Red
• Number of Characters: 4 alphanumeric characters
• Character Height: 0.54 inches
• Interface: I2C (Inter-Integrated Circuit)
• I2C Addresses: 0x70 (default), selectable with solder jumpers
• Backpack Chipset: HT16K33 driver

1. Power Connection: Connect the 3V pin to the 3.3V output on your Feather board and the GND pin to a ground pin on the Feather.
2. I2C Connection: Connect the SDA and SCL pins to their corresponding SDA and SCL pins on the Feather board.
3. Address Selection: If using multiple FeatherWings, adjust the I2C address using the solder jumpers on the back of the board.
4. Stacking: If stacking with other FeatherWings, ensure that the pins are aligned correctly and that there are no conflicts with I2C addresses.

• Ensure that the power supply is within the specified voltage range to prevent damage.
• When stacking multiple FeatherWings, check for pin compatibility and address conflicts.
• Use pull-up resistors on the I2C lines if they are not already present on the Feather board.
• Avoid exposing the display to direct sunlight for extended periods to prevent fading.

#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 to show it
  delay(1000);                     // Wait for a second
  alpha4.clear();                  // Clear the display
  alpha4.writeDisplay();           // Send the clear command to the display
  delay(1000);                     // Wait for a second
}

• Display Not Lighting Up: Ensure that the power connections are correct and secure. Check that the I2C lines are connected properly and that the correct I2C address is being used in the code.
• Garbled or Incorrect Characters: This can be due to incorrect data being sent to the display. Verify the code for any errors in the character data being written to the display.
• Multiple Displays Interfering: If using more than one FeatherWing, ensure that each has a unique I2C address set by adjusting the solder jumpers.

• Double-check wiring connections and solder joints for any loose connections or shorts.
• Use the Wire library's Wire.beginTransmission() and Wire.endTransmission() functions to check for a response from the display's I2C address to confirm communication.
• Consult the Adafruit support forums and guides for additional help and resources.

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

Q: How do I change the brightness of the display? A: The HT16K33 driver chip supports PWM brightness control. Use the setBrightness() function provided by the Adafruit LED Backpack library to adjust the brightness level.

Q: Can I display special characters on the FeatherWing? A: The 14-segment display can show a variety of characters and symbols. Check the Adafruit GFX library for supported characters and custom glyph creation.