Skip to content

Instantly share code, notes, and snippets.

@monkbroc

monkbroc/pixel-wave.ino

Forked from anonymous/pixel-wave.ino
Created November 23, 2016 21:30
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save monkbroc/6805c656e5897450da4275c3bc0dfd72 to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save monkbroc/6805c656e5897450da4275c3bc0dfd72 to your computer and use it in GitHub Desktop.
Download ZIP

Revisions

  1. @invalid-email-address Anonymous created this gist Nov 23, 2016.
    72 changes: 72 additions & 0 deletions pixel-wave.ino
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,72 @@
    /* Pixel wave
    * Copyright 2016 Julien Vanier, MIT license
    *
    * Connect 3 photoresistors to analog inputs and drive a Dotstar/Neopixel strip from the 3 analog signals!
    */
    #include "application.h"
    #include "dotstar/dotstar.h"

    SYSTEM_THREAD(ENABLED);

    // IMPORTANT: Connect Dotstar strand to hardware SPI (Data => A5 and Clock => A3)
    #define PIXEL_COUNT 72
    #define BRIGHTNESS 255
    #define SPEED 10

    #define PIN_RED A0
    #define PIN_GREEN A1
    #define PIN_BLUE A6

    #define VOLTAGE_MAX_NOMINAL (3.3 * 256 / 4096)
    #define VOLTAGE_MAX_RED 0.190
    #define VOLTAGE_MAX_GREEN 0.220
    #define VOLTAGE_MAX_BLUE 0.130

    Adafruit_DotStar strip = Adafruit_DotStar(PIXEL_COUNT, DOTSTAR_BGR);

    uint32_t colors[PIXEL_COUNT] = { 0 };

    uint16_t pos = 0;

    void setup()
    {
    strip.begin();
    strip.setBrightness(BRIGHTNESS);
    strip.show();

    pinMode(PIN_RED, INPUT);
    pinMode(PIN_GREEN, INPUT);
    pinMode(PIN_BLUE, INPUT);
    }

    void loop() {
    updateColor();
    showStrip();
    delay(SPEED);
    }

    void updateColor() {
    colors[pos] = strip.Color(
    pinColor(PIN_RED, VOLTAGE_MAX_RED),
    pinColor(PIN_GREEN, VOLTAGE_MAX_GREEN),
    pinColor(PIN_BLUE, VOLTAGE_MAX_BLUE)
    );
    }

    uint8_t pinColor(pin_t pin, float voltageMax) {
    int value = (int)(analogRead(pin) * VOLTAGE_MAX_NOMINAL / voltageMax);
    if (value > 255) {
    value = 255;
    }

    return 255 - value;
    }

    void showStrip() {
    for (uint16_t i = 0; i < PIXEL_COUNT; i++) {
    uint16_t n = (i + pos) % PIXEL_COUNT;
    strip.setPixelColor(PIXEL_COUNT - i, colors[n]);
    }
    strip.show();
    pos = (pos + 1) % PIXEL_COUNT;
    }