How to Use Adafruit HT16K33 Breakout 16x8 LED Matrix Driver: Examples, Pinouts, and Specs

The Adafruit HT16K33 Breakout is a versatile LED matrix driver module designed to control a 16x8 matrix, totaling 128 LEDs. It utilizes the HT16K33 chip to manage individual LED states, offering an I2C interface for communication with microcontrollers such as Arduino, Raspberry Pi, and others. This breakout is ideal for creating digital signage, gaming displays, or any project requiring a bright, customizable LED array.

• Digital clocks and timers
• Scrolling text displays
• Simple graphics and animations
• Gaming displays and scoreboards
• Interactive art installations

• Supply Voltage (Vcc): 4.5V to 5.5V
• Logic Level Voltage: 3.3V (5V tolerant)
• Max Current (per LED): 20mA
• Max Current (total): 400mA (when all LEDs are on)
• Communication Interface: I2C
• I2C Address Range: 0x70 to 0x77 (selectable with solder jumpers)
• Operating Temperature: -40°C to +85°C

1. Power Connections: Connect the VCC pin to a 4.5V to 5.5V power supply and the GND pin to the ground.
2. I2C Connections: Connect the SDA and SCL pins to the corresponding I2C data and clock lines on your microcontroller.
3. Address Selection: Set the I2C address using the ADDR pins by soldering the appropriate jumpers.

• Ensure that the power supply is within the specified voltage range to prevent damage.
• Use pull-up resistors on the I2C lines if they are not provided by the microcontroller.
• Avoid driving all LEDs at maximum brightness simultaneously to prevent exceeding the maximum current rating.
• To reduce power consumption and heat, manage brightness levels efficiently.

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

Adafruit_8x16matrix matrix = Adafruit_8x16matrix();

void setup() {
  matrix.begin(0x70); // Initialize the matrix with the I2C address
  matrix.setBrightness(10); // Set brightness level (0 is dim, 15 is bright)
}

void loop() {
  matrix.clear(); // Clear the matrix display
  matrix.setCursor(0, 0); // Set cursor at top-left corner
  matrix.print("Hello"); // Print "Hello" on the matrix
  matrix.writeDisplay(); // Update the display with the new data
  delay(2000); // Wait for 2 seconds
}

Ensure that the Adafruit LED Backpack library is installed in your Arduino IDE before uploading this code to your Arduino UNO.

• LEDs Not Lighting Up: Check the power supply connections and ensure the I2C lines are properly connected.
• Dim Display: Increase the brightness using setBrightness() or check the power supply voltage.
• Incorrect Characters Displayed: Verify that the correct I2C address is used in the begin() function.

• Double-check wiring, especially the I2C connections.
• Use the i2cdetect tool or similar to confirm the device's I2C address.
• Ensure that there are no solder bridges on the ADDR pins that might cause an incorrect address setting.
• If using multiple HT16K33 devices on the same I2C bus, ensure each has a unique address.

Q: Can I chain multiple HT16K33 breakouts together? A: Yes, you can connect multiple devices on the same I2C bus with different addresses.

Q: How do I change the I2C address of the breakout? A: Solder the appropriate combination of ADDR jumpers to set the desired address.

Q: What is the maximum number of LEDs that can be controlled with one HT16K33 breakout? A: The breakout can control up to 128 LEDs arranged in a 16x8 matrix.

Q: Can the HT16K33 breakout be used with a 3.3V system? A: Yes, the logic level is 3.3V tolerant, but ensure that VCC is within the specified range.

For further assistance, consult the Adafruit HT16K33 Breakout forums or contact technical support.