software/ampel-firmware/led_effects.cpp

#include "led_effects.h"
/*****************************************************************
 * Configuration                                                 *
 *****************************************************************/
namespace config {
  const uint8_t max_brightness = MAX_BRIGHTNESS;
#if defined(MIN_BRIGHTNESS)
  const uint8_t min_brightness = MIN_BRIGHTNESS;
#else
  const uint8_t min_brightness = MAX_BRIGHTNESS;
#endif
  const uint8_t brightness_amplitude = config::max_brightness - config::min_brightness;
  const int kitt_tail = 3; // How many dimmer LEDs follow in K.I.T.T. wheel
  const uint16_t poor_air_quality_ppm = 1600; // Above this threshold, LED breathing effect is faster.
  bool night_mode = false; //NOTE: Use a class instead? NightMode could then be another state.

#if !defined(LED_COUNT)
#  define LED_COUNT 12
#endif

  const uint16_t led_count = LED_COUNT;

#if LED_COUNT == 12
  //NOTE: One value has been prepended, to make calculations easier and avoid out of bounds index.
  const uint16_t co2_ticks[led_count + 1] = { 0, 500, 600, 700, 800, 900, 1000, 1200, 1400, 1600, 1800, 2000, 2200 }; // [ppm]
  // For a given LED, which color should be displayed? First LED will be pure green (hue angle 120°),
  // LEDs >= 1600ppm will be pure red (hue angle 0°), LEDs in-between will be yellowish.
  const uint16_t led_hues[led_count] = { 21845U, 19114U, 16383U, 13653U, 10922U, 8191U, 5461U, 2730U, 0, 0, 0, 0 }; // [hue angle]
#elif LED_COUNT == 16
  const uint16_t co2_ticks[led_count + 1] = { 0, 500, 600, 700, 800, 900, 1000, 1100, 1200,
                                              1300, 1400, 1500, 1600, 1700, 1800, 2000, 2200 }; // [ppm]
  const uint16_t led_hues[led_count] = {21845U, 19859U, 17873U, 15887U, 13901U, 11915U, 9929U, 7943U,
                                         5957U, 3971U, 1985U, 0, 0, 0, 0, 0}; // [hue angle]
#else
#  error "Only 12 and 16 LEDs rings are currently supported."
#endif
}

#if defined(ESP8266)
// NeoPixels on GPIO05, aka D1 on ESP8266.
const int NEOPIXELS_PIN = 5;
#elif defined(ESP32)
// NeoPixels on GPIO23 on ESP32. To avoid conflict with LoRa_SCK on TTGO.
const int NEOPIXELS_PIN = 23;
#endif

Adafruit_NeoPixel pixels(config::led_count, NEOPIXELS_PIN, NEO_GRB + NEO_KHZ800);

namespace led_effects {
  //On-board LED on D4, aka GPIO02
  const int ONBOARD_LED_PIN = 2;

  void setupOnBoardLED() {
    pinMode(ONBOARD_LED_PIN, OUTPUT);
  }

  void onBoardLEDOff() {
    //NOTE: OFF is LOW on ESP32 and HIGH on ESP8266 :-/
#ifdef ESP8266
    digitalWrite(ONBOARD_LED_PIN, HIGH);
#else
    digitalWrite(ONBOARD_LED_PIN, LOW);
#endif
  }

  void onBoardLEDOn() {
#ifdef ESP8266
    digitalWrite(ONBOARD_LED_PIN, LOW);
#else
    digitalWrite(ONBOARD_LED_PIN, HIGH);
#endif
  }

  void LEDsOff() {
    pixels.clear();
    pixels.show();
    onBoardLEDOff();
  }

  void showColor(int32_t color) {
    config::night_mode = true; // In order to avoid overwriting the desired color next time CO2 is displayed
    pixels.setBrightness(255);
    pixels.fill(color);
    pixels.show();
  }

  void setupRing() {
    pixels.begin();
    pixels.setBrightness(config::max_brightness);
    LEDsOff();
    sensor_console::defineCommand("night_mode", toggleNightMode, F("(Toggles night mode on/off)"));
    sensor_console::defineIntCommand("color", showColor, F("0xFF0015 (Shows color, specified as RGB, for debugging)"));
  }

  void toggleNightMode() {
    config::night_mode = !config::night_mode;
    if (config::night_mode) {
      Serial.println(F("NIGHT MODE!"));
      LEDsOff();
    } else {
      Serial.println(F("DAY MODE!"));
    }
  }

  //NOTE: basically one iteration of KITT wheel
  void showWaitingLED(uint32_t color) {
    using namespace config;
    delay(80);
    if (night_mode) {
      return;
    }
    static uint16_t kitt_offset = 0;
    pixels.clear();
    for (int j = kitt_tail; j >= 0; j--) {
      int ledNumber = abs((kitt_offset - j + led_count) % (2 * led_count) - led_count) % led_count; // Triangular function
      pixels.setPixelColor(ledNumber, color * pixels.gamma8(255 - j * 76) / 255);
    }
    pixels.show();
    kitt_offset++;
  }

  // Start K.I.T.T. led effect. Red color as default.
  // Simulate a moving LED with tail. First LED starts at 0, and moves along a triangular function. The tail follows, with decreasing brightness.
  // Takes approximately 1s for each direction.
  void showKITTWheel(uint32_t color, uint16_t duration_s) {
    pixels.setBrightness(config::max_brightness);
    for (int i = 0; i < duration_s * config::led_count; ++i) {
      showWaitingLED(color);
    }
  }

  /*
   * For a given CO2 level and ledId, which brightness should be displayed? 0 for off, 255 for on. Something in-between for partial LED.
   * For example, for 1500ppm, every LED between 0 and 7 (500 -> 1400ppm) should be on, LED at 8 (1600ppm) should be half-on.
   */
  uint8_t getLedBrightness(uint16_t co2, int ledId) {
    if (co2 >= config::co2_ticks[ledId + 1]) {
      return 255;
    } else {
      if (2 * co2 >= config::co2_ticks[ledId] + config::co2_ticks[ledId + 1]) {
        // Show partial LED if co2 more than halfway between ticks.
        return 27; // Brightness isn't linear, so 27 / 255 looks much brighter than 10%
      } else {
        // LED off because co2 below previous tick
        return 0;
      }
    }
  }

  /**
   * If enabled, slowly varies the brightness between MAX_BRIGHTNESS & MIN_BRIGHTNESS.
   */
  void breathe(int16_t co2) {
    static uint8_t breathing_offset = 0;
    uint16_t brightness = config::min_brightness + pixels.sine8(breathing_offset) * config::brightness_amplitude / 255;
    pixels.setBrightness(brightness);
    pixels.show();
    breathing_offset += co2 > config::poor_air_quality_ppm ? 6 : 3; // breathing speed. +3 looks like slow human breathing.
  }

  /**
   * Fills the whole ring with green, yellow, orange or black, depending on co2 input and CO2_TICKS.
   */
  void displayCO2color(uint16_t co2) {
    if (config::night_mode) {
      return;
    }
    pixels.setBrightness(config::max_brightness);
    for (int ledId = 0; ledId < config::led_count; ++ledId) {
      uint8_t brightness = getLedBrightness(co2, ledId);
      pixels.setPixelColor(ledId, pixels.ColorHSV(config::led_hues[ledId], 255, brightness));
    }
    pixels.show();
    if (config::brightness_amplitude > 0) {
      breathe(co2);
    }
  }

  void showRainbowWheel(uint16_t duration_ms) {
    if (config::night_mode) {
      return;
    }
    static uint16_t wheel_offset = 0;
    static uint16_t sine_offset = 0;
    unsigned long t0 = millis();
    pixels.setBrightness(config::max_brightness);
    while (millis() - t0 < duration_ms) {
      for (int i = 0; i < config::led_count; i++) {
        pixels.setPixelColor(i, pixels.ColorHSV(i * 65535 / config::led_count + wheel_offset));
        wheel_offset += (pixels.sine8(sine_offset++ / 50) - 127) / 2;
      }
      pixels.show();
      delay(10);
    }
  }

  void redAlert() {
    if (config::night_mode) {
      onBoardLEDOn();
      delay(500);
      onBoardLEDOff();
      delay(500);
      return;
    }
    for (int i = 0; i < 10; i++) {
      pixels.setBrightness(static_cast<int>(config::max_brightness * (1 - i * 0.1)));
      delay(50);
      pixels.fill(color::red);
      pixels.show();
    }
  }

  /**
   * Displays a complete blue circle, and starts removing LEDs one by one.
   * Does nothing in night mode and returns false then. Returns true if
   * the countdown has finished. Can be used for calibration, e.g. when countdown is 0.
   * NOTE: This function is blocking and returns only after the button has
   * been released or after every LED has been turned off.
   */
  bool countdownToZero() {
    if (config::night_mode) {
      Serial.println(F("Night mode. Not doing anything."));
      delay(1000); // Wait for a while, to avoid coming back to this function too many times when button is pressed.
      return false;
    }
    pixels.fill(color::blue);
    pixels.show();
    int countdown;
    for (countdown = config::led_count; countdown >= 0 && !digitalRead(0); countdown--) {
      pixels.setPixelColor(countdown, color::black);
      pixels.show();
      Serial.println(countdown);
      delay(500);
    }
    return countdown < 0;
  }
}