How to Use Qwiic D-Pad Button Breakout with I2C Interface: Examples, Pinouts, and Specs

The Qwiic D-Pad Button Breakout (Manufacturer Part ID: IFB-40003) by Playing With Fusion is a compact and versatile breakout board designed for directional input. It features a D-Pad button interface that communicates via the I2C protocol, making it easy to integrate into microcontroller-based projects. This component is ideal for applications requiring simple directional control, such as menu navigation, gaming interfaces, or robotic control systems.

• User interface navigation for embedded systems
• Gaming controllers and retro gaming projects
• Robotics control panels
• Menu selection for IoT devices
• Educational projects and prototyping

The Qwiic D-Pad Button Breakout is designed for simplicity and ease of use. Below are its key technical details:

The Qwiic D-Pad Button Breakout uses a 4-pin Qwiic connector for I2C communication. Below is the pinout:

1. Power Supply: Connect the breakout board to a 3.3V power source using the Qwiic connector.
2. I2C Communication: Ensure the SDA and SCL lines are connected to the corresponding pins on your microcontroller (e.g., Arduino UNO).
3. Address Configuration: The default I2C address is 0x20. If multiple devices are used, ensure there are no address conflicts.

To connect the Qwiic D-Pad Button Breakout to an Arduino UNO:

• Use a Qwiic cable to connect the breakout board to a Qwiic Shield attached to the Arduino UNO.
• Alternatively, use jumper wires to connect:
  • GND to GND
  • 3.3V to 3.3V
  • SDA to A4 (on Arduino UNO)
  • SCL to A5 (on Arduino UNO)

Below is an example Arduino sketch to read button presses from the Qwiic D-Pad Button Breakout:

#include <Wire.h>

// Define the I2C address of the Qwiic D-Pad Button Breakout
#define DPAD_I2C_ADDRESS 0x20

void setup() {
  Wire.begin(); // Initialize I2C communication
  Serial.begin(9600); // Start serial communication for debugging
  Serial.println("Qwiic D-Pad Button Breakout Test");
}

void loop() {
  Wire.requestFrom(DPAD_I2C_ADDRESS, 1); // Request 1 byte from the D-Pad
  if (Wire.available()) {
    uint8_t buttonState = Wire.read(); // Read the button state

    // Decode the button state
    if (buttonState & 0x01) Serial.println("Up button pressed");
    if (buttonState & 0x02) Serial.println("Down button pressed");
    if (buttonState & 0x04) Serial.println("Left button pressed");
    if (buttonState & 0x08) Serial.println("Right button pressed");
    if (buttonState & 0x10) Serial.println("Center button pressed");
  }
  delay(100); // Small delay to avoid spamming the serial monitor
}

• Voltage Compatibility: The breakout board operates at 3.3V. If using a 5V microcontroller, ensure proper level shifting for the I2C lines.
• Pull-Up Resistors: The Qwiic D-Pad includes onboard pull-up resistors for the I2C lines. Avoid adding additional pull-ups unless necessary.
• Debouncing: The onboard firmware handles basic debouncing, but additional software debouncing may be required for specific applications.

1. No Response from the Breakout Board

   • Ensure the board is powered with 3.3V.
   • Verify the I2C connections (SDA and SCL).
   • Check for address conflicts on the I2C bus.

2. Incorrect Button Readings

   • Ensure the I2C address in your code matches the breakout board's address.
   • Verify that the Qwiic cable or jumper wires are securely connected.

3. I2C Communication Errors

   • Check for proper pull-up resistors on the I2C lines.
   • Ensure the microcontroller supports 3.3V logic levels or use level shifters.

Q: Can I change the I2C address of the breakout board?
A: No, the Qwiic D-Pad Button Breakout has a fixed I2C address of 0x20.

Q: Does the breakout board support 5V operation?
A: No, the board is designed for 3.3V operation. Use a level shifter if connecting to a 5V microcontroller.

Q: How do I detect multiple button presses?
A: The button state byte returned via I2C is a bitmask. Multiple bits can be set simultaneously to indicate multiple button presses.

Q: Can I use this breakout board with Raspberry Pi?
A: Yes, the Qwiic D-Pad Button Breakout is compatible with any device that supports I2C communication, including Raspberry Pi.

By following this documentation, you can easily integrate the Qwiic D-Pad Button Breakout into your projects for reliable and intuitive directional input.