naokisekiguchi/index.html

## index.html
<!doctype html>
<html>
    <head>
        <meta charset="UTF-8" />
        <script src="js/webgpioi2c.js"></script>
        <script src="js/task.js"></script>
    </head>
    <body>
        <div id="angle">angle</div>
    </body>
</html>

## servo.js
// task.js ライブラリ
const { spawn, sleep } = task;
// document 内のリソースが読み終わるのを待つ
document.addEventListener("DOMContentLoaded", () => {

  // task.js の spawn 関数内では Promise が同期的に記述できる
  spawn(function() {

    // I2C へのアクセサを取得
    const accessor = yield navigator.requestI2CAccess();
    // I2C 0 ポートを使うので、0 を指定してポートを取得
    const port = accessor.ports.get(0);

    const pcs9685 = new PCA9685(port,0x40);
    yield pcs9685.init(0.00050,0.00240,180);

    let angle = 10;

    setInterval( ()=>{
      spawn(function(){
        angle = (angle<=10) ? 170 : 10;
        yield pcs9685.setServo(0,angle);
        document.getElementById("angle").innerHTML = angle;
      });
    },1000);
  });
});

const PCA9685 = function(i2cPort,slaveAddress){
  this.i2cPort = i2cPort;
  this.slaveAddress = slaveAddress;
  this.minPulse=null;
  this.maxPulse=null;
  this.angleRange=null;
};

PCA9685.prototype = {

  init: function(minPulse,maxPulse,angleRange,noSetZero){
    const self = this;
    if(self.minPulse && self.maxPulse && self.angleRange){
      console.log("alredy set param");
    }
    if(minPulse && maxPulse && angleRange){
      self.minPulse = minPulse;
      self.maxPulse = maxPulse;
      self.angleRange = angleRange;
      console.log("set servo setting.");
    }else{
      self.minPulse = 0.0005;
      self.maxPulse = 0.0024;
      self.angleRange = 180;
      console.log("set defaul servo setting.");
    }

    return new Promise(function(resolve, reject){
      spawn(function(){
        const slave = yield self.i2cPort.open(self.slaveAddress);

        yield slave.write8(0x00,0x00);
        yield sleep(10);
        yield slave.write8(0x01,0x04);
        yield sleep(10);

        yield slave.write8(0x00,0x10);
        yield sleep(10);
        yield slave.write8(0xfe,0x64);
        yield sleep(10);
        yield slave.write8(0x00,0x00);
        yield sleep(10);
        yield slave.write8(0x06,0x00);
        yield sleep(10);
        yield slave.write8(0x07,0x00);
        yield sleep(300);
        if ( !noSetZero ){
          for ( let servoPort = 0 ; servoPort < 16 ; servoPort ++ ){
            yield self.setServo(servoPort , 0 );
          }
        }
        resolve();
      });
    });
  },
  setServo: function(servoPort,angle){
    const self = this;

    const portStart = 8;
    const portInterval = 4;

    const freq = 61; // Hz
    const tickSec = ( 1 / freq ) / 4096; // 1bit resolution( sec )

    let minPulse,maxPulse,angleRange,pulseRange;
    if(self.minPulse && self.maxPulse && self.angleRange){
      minPulse = self.minPulse;
      maxPulse = self.maxPulse;
      pulseRange = maxPulse - minPulse;
      angleRange = self.angleRange;
    }else{
      console.log("wrong param.");
    }
    const pulse = minPulse + angle / angleRange * pulseRange;
    const ticks = Math.round(pulse / tickSec);

    const tickH = (( ticks >> 8 ) & 0x0f);
    const tickL = (ticks & 0xff);

    return new Promise(function(resolve, reject){
      spawn(function(){
        const slave = yield self.i2cPort.open(self.slaveAddress);
        const pwm = Math.round(portStart + servoPort * portInterval);

        yield slave.write8( pwm + 1, tickH);
        yield sleep(1);
        yield slave.write8( pwm, tickL);

        resolve();
      });
    });
  }
};
	<!doctype html>
	<html>
	<head>
	<meta charset="UTF-8" />
	<script src="js/webgpioi2c.js"></script>
	<script src="js/task.js"></script>
	</head>
	<body>
	<div id="angle">angle</div>
	</body>
	</html>
	// task.js ライブラリ
	const { spawn, sleep } = task;
	// document 内のリソースが読み終わるのを待つ
	document.addEventListener("DOMContentLoaded", () => {

	// task.js の spawn 関数内では Promise が同期的に記述できる
	spawn(function() {

	// I2C へのアクセサを取得
	const accessor = yield navigator.requestI2CAccess();
	// I2C 0 ポートを使うので、0 を指定してポートを取得
	const port = accessor.ports.get(0);

	const pcs9685 = new PCA9685(port,0x40);
	yield pcs9685.init(0.00050,0.00240,180);

	let angle = 10;

	setInterval( ()=>{
	spawn(function(){
	angle = (angle<=10) ? 170 : 10;
	yield pcs9685.setServo(0,angle);
	document.getElementById("angle").innerHTML = angle;
	});
	},1000);
	});
	});

	const PCA9685 = function(i2cPort,slaveAddress){
	this.i2cPort = i2cPort;
	this.slaveAddress = slaveAddress;
	this.minPulse=null;
	this.maxPulse=null;
	this.angleRange=null;
	};

	PCA9685.prototype = {

	init: function(minPulse,maxPulse,angleRange,noSetZero){
	const self = this;
	if(self.minPulse && self.maxPulse && self.angleRange){
	console.log("alredy set param");
	}
	if(minPulse && maxPulse && angleRange){
	self.minPulse = minPulse;
	self.maxPulse = maxPulse;
	self.angleRange = angleRange;
	console.log("set servo setting.");
	}else{
	self.minPulse = 0.0005;
	self.maxPulse = 0.0024;
	self.angleRange = 180;
	console.log("set defaul servo setting.");
	}

	return new Promise(function(resolve, reject){
	spawn(function(){
	const slave = yield self.i2cPort.open(self.slaveAddress);

	yield slave.write8(0x00,0x00);
	yield sleep(10);
	yield slave.write8(0x01,0x04);
	yield sleep(10);

	yield slave.write8(0x00,0x10);
	yield sleep(10);
	yield slave.write8(0xfe,0x64);
	yield sleep(10);
	yield slave.write8(0x00,0x00);
	yield sleep(10);
	yield slave.write8(0x06,0x00);
	yield sleep(10);
	yield slave.write8(0x07,0x00);
	yield sleep(300);
	if ( !noSetZero ){
	for ( let servoPort = 0 ; servoPort < 16 ; servoPort ++ ){
	yield self.setServo(servoPort , 0 );
	}
	}
	resolve();
	});
	});
	},
	setServo: function(servoPort,angle){
	const self = this;

	const portStart = 8;
	const portInterval = 4;

	const freq = 61; // Hz
	const tickSec = ( 1 / freq ) / 4096; // 1bit resolution( sec )

	let minPulse,maxPulse,angleRange,pulseRange;
	if(self.minPulse && self.maxPulse && self.angleRange){
	minPulse = self.minPulse;
	maxPulse = self.maxPulse;
	pulseRange = maxPulse - minPulse;
	angleRange = self.angleRange;
	}else{
	console.log("wrong param.");
	}
	const pulse = minPulse + angle / angleRange * pulseRange;
	const ticks = Math.round(pulse / tickSec);

	const tickH = (( ticks >> 8 ) & 0x0f);
	const tickL = (ticks & 0xff);

	return new Promise(function(resolve, reject){
	spawn(function(){
	const slave = yield self.i2cPort.open(self.slaveAddress);
	const pwm = Math.round(portStart + servoPort * portInterval);

	yield slave.write8( pwm + 1, tickH);
	yield sleep(1);
	yield slave.write8( pwm, tickL);

	resolve();
	});
	});
	}
	};