How to Use Adafruit Neo Trinkey: Examples, Pinouts, and Specs

The Adafruit Neo Trinkey is a small form-factor development board designed for quick and easy projects. Based on the ATSAMD21 microcontroller, it is equipped with four RGB NeoPixel LEDs and a capacitive touch button. The board is designed to plug directly into a USB port for programming and power, making it an ideal choice for creating custom USB devices, lightweight decorations, or for educational purposes to teach programming and electronics.

• Custom USB devices (e.g., volume control, keyboard shortcuts)
• Wearable electronics and cosplay props
• Educational tools for learning programming and electronics
• Quick prototyping of light-based projects

• Microcontroller: ATSAMD21E18 32-bit ARM Cortex-M0+
• Operating Voltage: 3.3V
• Input Voltage (recommended): 5V (from USB)
• Digital I/O Pins: 4 (multiplexed with NeoPixel LEDs and touch input)
• Onboard LEDs: 4 x NeoPixel RGB LEDs
• Connectivity: USB Type-A connector
• Flash Memory: 256KB
• SRAM: 32KB
• Clock Speed: 48 MHz

1. Connecting to a Computer:

   • Plug the Adafruit Neo Trinkey directly into a USB port on your computer.
   • Ensure that the USB port provides sufficient power for the board and connected peripherals.

2. Programming:

   • Use the Arduino IDE or other compatible software to write and upload code to the board.
   • Select the appropriate board and port from the tools menu in the Arduino IDE.

3. Interacting with NeoPixels:

   • Use the Adafruit NeoPixel library to control the onboard LEDs.
   • The NeoPixel data pin is connected to digital pin 1 of the ATSAMD21.

4. Using the Capacitive Touch:

   • The capacitive touch input can be read using the touchRead() function in your code.
   • It is connected to digital pin 2 of the ATSAMD21.

• Power Limits: Do not exceed the recommended voltage and current specifications.
• ESD Precautions: Handle the board with care to avoid electrostatic discharge damage.
• USB Port Strain: Avoid applying excessive force to the board when plugged in to prevent damage to the USB port.
• Library Compatibility: Ensure you have the latest Adafruit NeoPixel library installed for LED control.

#include <Adafruit_NeoPixel.h>

#define PIN 1
#define NUMPIXELS 4

Adafruit_NeoPixel pixels(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  pixels.begin(); // Initialize the NeoPixel library.
}

void loop() {
  for(int i=0; i<NUMPIXELS; i++) {
    pixels.setPixelColor(i, pixels.Color(150, 0, 0)); // Moderately bright red color.
    pixels.show(); // This sends the updated pixel color to the hardware.
    delay(500); // Delay for half a second.
    pixels.setPixelColor(i, pixels.Color(0,0,0)); // Turn off the pixel.
    pixels.show();
    delay(500);
  }
}

• NeoPixels not lighting up: Ensure that the NeoPixel library is correctly included and that the pin number is set to 1.
• Board not recognized by computer: Check the USB cable and port. Try a different cable or port if necessary.
• Touch input not responsive: Make sure your finger is in close proximity to the touch pad and that the board is properly powered.

• LED Issues: Verify the color values and pixel indices in your code. Check for any loose connections if using external NeoPixels.
• Connectivity Issues: Restart the Arduino IDE and reconnect the board. Ensure the correct drivers are installed.
• Code Errors: Double-check your code for syntax errors or incorrect function calls. Use serial debugging to help identify issues.

Q: Can I use the Neo Trinkey with a battery? A: The Neo Trinkey is designed to be powered via USB. Using a battery would require additional circuitry.

Q: How do I update the firmware on the Neo Trinkey? A: Firmware updates can be done through the Arduino IDE or other compatible flash tools, following Adafruit's guides.

Q: Is the Neo Trinkey compatible with CircuitPython? A: Yes, the Neo Trinkey is compatible with CircuitPython, and Adafruit provides resources for using CircuitPython with the board.