sleeplight/runSchedule.js

const Gpio = require("pigpio").Gpio;

const schedule = require("./schedule.json");

const HZ = 40000;
const NAP_DURATION = 100 * 60 * 1000;
const DEBUG = !!process.env["DEBUG"];

//Let's setup our connections to our physical hardware devices.
let ledRed = new Gpio(12, {mode: Gpio.OUTPUT});
ledRed.hardwarePwmWrite(HZ, 0);
let ledGreen = new Gpio(13, {mode: Gpio.OUTPUT});
let napButton = new Gpio(6, {mode: Gpio.INPUT, pullUpDown: Gpio.PUD_UP, alert: true });
napButton.glitchFilter(10000);

//Make an easily searchable array so we can find what color it should
//be using at any given time.
let timings = schedule.times.reduce((result, time)  => {
	result.push({start: time.time, color: time.color});
	return result;
}, []).sort((a, b) => a.start - b.start).map((timing, i, arr) => {
	timing.end = arr[(i+1) % arr.length].start;
	return timing;
});

//We need to split the last scheduled interval at midnight
//(and fill it in for the start of the day)
splitAtMidnight(timings);

//Initialize State
let state = {
  color: "red",
  napTime: false,
}

//Make sure the color is set correctly in state for the current time before we start.
//It will automatically update every seconds, but it might be wrong for a second.
updateColorState();


//Set intervals to update LED lights.
//********
let updateColorStateInterval = setInterval(updateColorState, 1000);
let renderInterval = setInterval(render, 50);
let debugInterval = DEBUG && setInterval(logLEDStatus, 2000);
//********

napButton.on("alert", startNap);
DEBUG && process.on('SIGUSR2', () => {
  console.debug("Simulating button press!");
  startNap();
});

function startNap(level, tick) {
  console.log("Button alert recieved.  Starting nap time!");
	state = { ...state,
		napTime: true,
		napEnd: Date.now() + NAP_DURATION
	}
}


function updateColorState() {
	let newColor = state.color;
	switch(state.napTime) {
    case true:
      console.log("Nap time until :", state.napEnd);
      if(Date.now() < state.napEnd) {
        newColor = "red";
        break;
      } else {
        state = { ...state,
          napTime: false,
          napEnd: 0,
        };
      }
    case false: 
      console.log("NO NAP!");
      let time = getTime();
      let timing = timings.find(x => x.start <= time && x.end > time);
      newColor = timing.color
  }
  if(newColor !== state.color) {
    console.log("setting color state to", newcolor);
    
    state = { ...state,
      color: newColor,
    };
  }
}

function render()  {
	switch(state.color) {
		case "red":
      if(ledGreen.digitalRead()) {
        DEBUG && console.log("Turning off Green LED.");
				return ledGreen.digitalWrite(0);
      }

      DEBUG && !ledRed.getPwmDutyCycle() && console.log("Turning on Red LED");
			return ledRed.hardwarePwmWrite(HZ, getBrightness(Date.now()));
			break;
		case "green":
			if(ledRed.getPwmDutyCycle()) {
        DEBUG && console.log("Turning off Red LED.");
				return ledRed.hardwarePwmWrite(0);
			}
      if(!ledGreen.digitalRead()) {
        DEBUG && console.log("Turning on Green LED.");
				return ledGreen.digitalWrite(1);
			}
			//Commenting out.  Probably don't need breathing on green leds
			//return ledGreen.hardwarePwmWrite(HZ, getBrightness(Date.now()));
			break;
	}
}

function logLEDStatus() {
  console.log({
    red: ledRed.getPwmDutyCycle(),
    green: ledGreen.digitalRead(),
  });
}

//get brightness for time value for LED pulse breathing 
function getBrightness(time) {
  //These values should be configurable, maybe?
	return Math.floor(breathingCurve(time, 6500, 200000, 800000));
}

//algorithm for pulse breathing LEDs
function breathingCurve(x, interval = 3000, min, max) {
	let t = x * Math.PI/(interval/2);
	let y = Math.sin(t + Math.sin(t) * 0.2);
        let untranslatedY = Math.sin(t + Math.sin(t) * 0.25);
        y = (untranslatedY + 1)/2;
	return y * (max - min) + min;
}

//split the last time interval at midnight and add the remaining to the
//beginning of the the array.
function splitAtMidnight(arr) {
	let last = arr[arr.length -1];
	arr.unshift({ ...last, start: 0});
	arr[arr.length - 1].end = 2400;
}

//get current time in military style time.  This format is used for ease of 
//human input in conviguration file.  I should have converted to Date when read
//from configuration.. oh well, I'll fix that later.
function getTime() {
	let date = new Date(Date.now());
	return (date.getHours() * 100) + date.getMinutes() + 1
}