How to Use Adafruit 7 Segment FeatherWing - Green: Examples, Pinouts, and Specs

The Adafruit 7 Segment FeatherWing - Green is a compact, easy-to-use display module designed for integration with the Adafruit Feather ecosystem. This module features a 4-digit, 7-segment LED display that allows users to present numerical data or simple alphanumeric characters in a clear and visible format. Common applications include clocks, timers, counters, and readouts for various sensors.

• Display Type: 4-digit, 7-segment LED
• Color: Green
• Operating Voltage: 3.3V to 5V
• Communication: I2C interface
• I2C Addresses: 0x70 (default) - 0x77 (selectable with solder jumpers)
• Dimensions: 51mm x 23mm x 5mm / 2.0" x 0.9" x 0.2"
• Weight: 4.8 grams

1. Mounting: Align the headers of the 7 Segment FeatherWing with the corresponding sockets on your Feather board and solder them together.
2. Powering Up: Once connected, power your Feather board as usual. The display should light up if the connections are correct.
3. I2C Communication: The FeatherWing uses I2C for communication, which requires only two data lines (SDA and SCL). Ensure that these lines are connected properly to your Feather board.

To control the 7 Segment FeatherWing, you will need to use the Adafruit LED Backpack library, which can be installed via the Arduino Library Manager.

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

Adafruit_7segment matrix = Adafruit_7segment();

void setup() {
  matrix.begin(0x70); // Initialize the display with its I2C address
}

void loop() {
  matrix.print(1234, DEC); // Display the number 1234
  matrix.writeDisplay();   // Send the data to the display
  delay(5000);             // Wait for 5 seconds
}

• I2C Addressing: If you are using multiple I2C devices, ensure that each device has a unique address. The 7 Segment FeatherWing address can be changed by soldering the address jumpers on the back of the PCB.
• Power Supply: Do not exceed the recommended voltage as it may damage the display.
• Handling: Be careful when handling the display to avoid static discharge or mechanical stress.

• Display Not Lighting Up: Check the power supply and I2C connections. Ensure that the correct I2C address is being used in your code.
• Garbled Characters: This can be caused by incorrect data being sent to the display. Check your code for errors in the data output routines.
• Partial Display: If only part of the display is working, there may be a cold solder joint or a damaged segment. Re-solder any suspect connections and inspect the segments.

Q: Can I use the 7 Segment FeatherWing with a 5V Feather board? A: Yes, the display is compatible with both 3.3V and 5V logic levels.

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

Q: Can I display letters as well as numbers? A: Yes, the display can show some basic alphanumeric characters. Refer to the Adafruit LED Backpack library for supported characters.

Q: How many of these displays can I chain together? A: You can chain up to 8 displays together, each with a unique I2C address.

For further assistance, consult the Adafruit support forums or the detailed guides available on the Adafruit Learning System website.