satakagi/i2c-PCF8591.js

## i2c-PCF8591.js
// PCF8591 driver for CHIRIMEN raspberry pi3
// 4ch 8bit ADC, 1ch 8bit DAC
// CDS, Thermister, VR and a LED
// Programmed by Satoru Takagi

var PCF8591 = function(i2cPort,slaveAddress){
	if (!slaveAddress){
		slaveAddress = 0x48;
	}
	this.i2cPort = i2cPort;
	this.i2cSlave = null;
	this.slaveAddress = slaveAddress;
	this.refV = 3.3;
}

PCF8591.prototype = {
	init: async function(){
		this.i2cSlave = await this.i2cPort.open(this.slaveAddress);

	},
	readADC: async function(ch){
		if ( ch >=0 && ch < 4 ){
			var prev = await this.i2cSlave.read8(ch + 0x40); // prev data..
			var ans  = await this.i2cSlave.read8(ch + 0x40);
			return( this.refV * ans / 0xff );
		} else {
			return(-1);
		}
	},
	setDAC: async function(vl){
		var dav = Math.floor( 0xff * vl / this.refV ) & 0xff;
		console.log("setDAC:",dav);
		await this.i2cSlave.write8( 0x40, dav );
	}
};

## mainPcf.js
"use strict";

window.addEventListener(
	"load",
	function() {
		mainFunction();
	},
	false
);

var pcfPromise;

async function mainFunction() {
	try {
		var i2cAccess = await navigator.requestI2CAccess();
		var port = i2cAccess.ports.get(1);
		var pcf = new PCF8591(port);
		await pcf.init();
		pcfPromise = pcf;
		while (1) {
			var adv0 = await pcf.readADC(0);
			var adv1 = await pcf.readADC(1);
			var adv2 = await pcf.readADC(2);
			var adv3 = await pcf.readADC(3);
			adc0.innerHTML=adv0+"V";
			adc1.innerHTML=adv1+"V";
			adc2.innerHTML=adv2+"V";
			adc3.innerHTML=adv3+"V";
			await sleep(200);
		}
	} catch (error) {
		console.error("error", error);
	}
}

async function dac(v){
	var pcf = await pcfPromise;
	await pcf.setDAC(v);
}

## pcf.html
<!doctype html>
<html>

<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1">
  <title>i2c-BMP180</title>
  <script src="../../../polyfill/polyfill.js"></script>
  <script src="../../drivers/i2c-PCF8591.js"></script>
  <script src="./mainPcf.js"></script>
  <style>
    table,p {
      color: blue;
      text-align: center;
      font-size: 24px;
    }

    img {
      position: absolute;
      top: 50px;
      right: 0px;
      display: block;
      margin-left: auto;
      margin-right: auto;
    }
  </style>
</head>

<body>
  <p id="head">PCF8591</p>
  <img src="schematic.png" width="400"/>
  <table>
  <tr><td>ADC0</td><td id="adc0"></td></tr>
  <tr><td>ADC1</td><td id="adc1"></td></tr>
  <tr><td>ADC2</td><td id="adc2"></td></tr>
  <tr><td>ADC3</td><td id="adc3"></td></tr>
  <tr><td>DAC</td><td id="dac">
  	<input type="button" value="0V" onClick="dac(0)"/>
  	<input type="button" value="1.1V" onClick="dac(1.1)"/>
  	<input type="button" value="2.2V" onClick="dac(2.2)"/>
  	<input type="button" value="3.3V" onClick="dac(3.3)"/>
  </td></tr>
  </table>
</body>

</html>
	// PCF8591 driver for CHIRIMEN raspberry pi3
	// 4ch 8bit ADC, 1ch 8bit DAC
	// CDS, Thermister, VR and a LED
	// Programmed by Satoru Takagi

	var PCF8591 = function(i2cPort,slaveAddress){
	if (!slaveAddress){
	slaveAddress = 0x48;
	}
	this.i2cPort = i2cPort;
	this.i2cSlave = null;
	this.slaveAddress = slaveAddress;
	this.refV = 3.3;
	}

	PCF8591.prototype = {
	init: async function(){
	this.i2cSlave = await this.i2cPort.open(this.slaveAddress);

	},
	readADC: async function(ch){
	if ( ch >=0 && ch < 4 ){
	var prev = await this.i2cSlave.read8(ch + 0x40); // prev data..
	var ans = await this.i2cSlave.read8(ch + 0x40);
	return( this.refV * ans / 0xff );
	} else {
	return(-1);
	}
	},
	setDAC: async function(vl){
	var dav = Math.floor( 0xff * vl / this.refV ) & 0xff;
	console.log("setDAC:",dav);
	await this.i2cSlave.write8( 0x40, dav );
	}
	};
	"use strict";

	window.addEventListener(
	"load",
	function() {
	mainFunction();
	},
	false
	);

	var pcfPromise;

	async function mainFunction() {
	try {
	var i2cAccess = await navigator.requestI2CAccess();
	var port = i2cAccess.ports.get(1);
	var pcf = new PCF8591(port);
	await pcf.init();
	pcfPromise = pcf;
	while (1) {
	var adv0 = await pcf.readADC(0);
	var adv1 = await pcf.readADC(1);
	var adv2 = await pcf.readADC(2);
	var adv3 = await pcf.readADC(3);
	adc0.innerHTML=adv0+"V";
	adc1.innerHTML=adv1+"V";
	adc2.innerHTML=adv2+"V";
	adc3.innerHTML=adv3+"V";
	await sleep(200);
	}
	} catch (error) {
	console.error("error", error);
	}
	}

	async function dac(v){
	var pcf = await pcfPromise;
	await pcf.setDAC(v);
	}
	<!doctype html>
	<html>

	<head>
	<meta charset="UTF-8" />
	<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1">
	<title>i2c-BMP180</title>
	<script src="../../../polyfill/polyfill.js"></script>
	<script src="../../drivers/i2c-PCF8591.js"></script>
	<script src="./mainPcf.js"></script>
	<style>
	table,p {
	color: blue;
	text-align: center;
	font-size: 24px;
	}

	img {
	position: absolute;
	top: 50px;
	right: 0px;
	display: block;
	margin-left: auto;
	margin-right: auto;
	}
	</style>
	</head>

	<body>
	<p id="head">PCF8591</p>
	<img src="schematic.png" width="400"/>
	<table>
	<tr><td>ADC0</td><td id="adc0"></td></tr>
	<tr><td>ADC1</td><td id="adc1"></td></tr>
	<tr><td>ADC2</td><td id="adc2"></td></tr>
	<tr><td>ADC3</td><td id="adc3"></td></tr>
	<tr><td>DAC</td><td id="dac">
	<input type="button" value="0V" onClick="dac(0)"/>
	<input type="button" value="1.1V" onClick="dac(1.1)"/>
	<input type="button" value="2.2V" onClick="dac(2.2)"/>
	<input type="button" value="3.3V" onClick="dac(3.3)"/>
	</td></tr>
	</table>
	</body>

	</html>