The seesaw firmware that ships with the ATtiny817 breakout includes the ability to power up to 60 NeoPixels on one pin. This example displays a series of color wipes, a theatre chase effect in different colors, and a rainbow across a NeoPixel ring.

Follow the steps on the Arduino page to get set up.

NeoPixel Pins

There are 15 pins on the ATtiny817 breakout that can be used for powering NeoPixels. However, you can only use one pin at a time! The available pins are:

  • 0, 1, 2, 3, 20, 5, 6, 7, 8, 9, 12, 13, 14, 18, 19
Pins 15, 16 and 17 can NOT be used as NeoPixel pins with the seesaw firmware!

Wiring

Follow the instructions to add an external LED to your existing setup.

  • Use a STEMMA QT cable to connect the STEMMA QT connector on the Feather to the STEMMA QT connector on the breakout.
  • Connect NeoPixel ring GND to breakout GND
  • Connect NeoPixel ring IN (data in) to breakout pin 19
  • Connect NeoPIxel ring power to breakout VIN

Example Code

Open up File -> Examples -> Adafruit Seesaw -> NeoPixel -> NeoPixel_strandtest.

Before you upload it to your microcontroller, you must make a change for it to work with the ATtiny817 breakout.

This example will not work with the ATtiny817 breakout as is. You must update the pin before uploading the sketch!

Update the following line:

#define PIN 10

To one of the NeoPixel capable pins on the ATtiny817, such as pin 19 to match the wiring diagram:

#define PIN 19

You must do this before uploading the sketch, or it won't work with your setup!

#include <seesaw_neopixel.h>
#define PIN 10

// Parameter 1 = number of pixels in strip
// Parameter 2 = Arduino pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
//   NEO_KHZ800  800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
//   NEO_KHZ400  400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
//   NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)
//   NEO_RGB     Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
//   NEO_RGBW    Pixels are wired for RGBW bitstream (NeoPixel RGBW products)
seesaw_NeoPixel strip = seesaw_NeoPixel(12, PIN, NEO_GRB + NEO_KHZ800);

// IMPORTANT: To reduce NeoPixel burnout risk, add 1000 uF capacitor across
// pixel power leads, add 300 - 500 Ohm resistor on first pixel's data input
// and minimize distance between Arduino and first pixel.  Avoid connecting
// on a live circuit...if you must, connect GND first.

void setup() {
  Serial.begin(115200);
  
  while (!Serial) delay(10);   // wait until serial port is opened
  
  if(!strip.begin()){
    Serial.println("seesaw not found!");
    while(1) delay(10);
  }
  
  Serial.println(F("seesaw started OK!"));
  
  strip.show(); // Initialize all pixels to 'off'
}

void loop() {
  // Some example procedures showing how to display to the pixels:
  colorWipe(strip.Color(255, 0, 0), 50); // Red
  colorWipe(strip.Color(0, 255, 0), 50); // Green
  colorWipe(strip.Color(0, 0, 255), 50); // Blue
//colorWipe(strip.Color(0, 0, 0, 255), 50); // White RGBW
  // Send a theater pixel chase in...
  theaterChase(strip.Color(127, 127, 127), 50); // White
  theaterChase(strip.Color(127, 0, 0), 50); // Red
  theaterChase(strip.Color(0, 0, 127), 50); // Blue

  rainbow(20);
  rainbowCycle(20);
  theaterChaseRainbow(50);
}

// Fill the dots one after the other with a color
void colorWipe(uint32_t c, uint8_t wait) {
  for(uint16_t i=0; i<strip.numPixels(); i++) {
    strip.setPixelColor(i, c);
    strip.show();
    delay(wait);
  }
}

void rainbow(uint8_t wait) {
  uint16_t i, j;

  for(j=0; j<256; j++) {
    for(i=0; i<strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel((i+j) & 255));
    }
    strip.show();
    delay(wait);
  }
}

// Slightly different, this makes the rainbow equally distributed throughout
void rainbowCycle(uint8_t wait) {
  uint16_t i, j;

  for(j=0; j<256*5; j++) { // 5 cycles of all colors on wheel
    for(i=0; i< strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel(((i * 256 / strip.numPixels()) + j) & 255));
    }
    strip.show();
    delay(wait);
  }
}

//Theatre-style crawling lights.
void theaterChase(uint32_t c, uint8_t wait) {
  for (int j=0; j<10; j++) {  //do 10 cycles of chasing
    for (int q=0; q < 3; q++) {
      for (uint16_t i=0; i < strip.numPixels(); i=i+3) {
        strip.setPixelColor(i+q, c);    //turn every third pixel on
      }
      strip.show();

      delay(wait);

      for (uint16_t i=0; i < strip.numPixels(); i=i+3) {
        strip.setPixelColor(i+q, 0);        //turn every third pixel off
      }
    }
  }
}

//Theatre-style crawling lights with rainbow effect
void theaterChaseRainbow(uint8_t wait) {
  for (int j=0; j < 256; j++) {     // cycle all 256 colors in the wheel
    for (int q=0; q < 3; q++) {
      for (uint16_t i=0; i < strip.numPixels(); i=i+3) {
        strip.setPixelColor(i+q, Wheel( (i+j) % 255));    //turn every third pixel on
      }
      strip.show();

      delay(wait);

      for (uint16_t i=0; i < strip.numPixels(); i=i+3) {
        strip.setPixelColor(i+q, 0);        //turn every third pixel off
      }
    }
  }
}

// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos) {
  WheelPos = 255 - WheelPos;
  if(WheelPos < 85) {
    return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  }
  if(WheelPos < 170) {
    WheelPos -= 85;
    return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
  WheelPos -= 170;
  return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
}

Once successfully uploaded, your NeoPixel light show will begin! Color wipe, followed by theatre chase, followed by full rainbow, followed by rainbow cycle.

This guide was first published on Oct 20, 2021. It was last updated on 2021-10-20 12:04:17 -0400.

This page (NeoPixel) was last updated on Nov 27, 2021.

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