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IoT_lover
Published © GPL3+

Arduino - Web-Based Gauge

This project shows how to monitor Arduino using a web-based gauge.

BeginnerFull instructions provided8,660

Things used in this project

Hardware components

Arduino UNO
Arduino UNO
×1
USB Cable 2.0 Type A/B for Arduino Uno
DIYables USB Cable 2.0 Type A/B for Arduino Uno
×1
PHPoC WiFi Shield for Arduino
PHPoC WiFi Shield for Arduino
×1
Potentiometer
DIYables Potentiometer
×1
Jumper Wires
DIYables Jumper Wires
×1
Prototype Expansion Board for Arduino Uno
DIYables Prototype Expansion Board for Arduino Uno
Optional
×1
Starter Kit
DIYables Starter Kit
×1
Arduino Uno Case
DIYables Arduino Uno Case
×1

Story

Read more

Code

Arduino Code

Arduino
#include "SPI.h"
#include "Phpoc.h"

PhpocServer server(80);
boolean alreadyConnected = false;
int sensorPin = A0;   
float sensorValue = 0;  // variable to store the value coming from the sensor
int lastAngle = 0;

void setup() {
    Serial.begin(9600);
    while(!Serial)
        ;
    
    Phpoc.begin(PF_LOG_SPI | PF_LOG_NET);

    server.beginWebSocket("gauge");

    Serial.print("WebSocket server address : ");
    Serial.println(Phpoc.localIP());    
}

void loop() {
    // when the client sends the first byte, say hello:
    PhpocClient client = server.available();
    
    if (client) {
        sensorValue = 0;
        for(int i = 0; i < 100; i++)
            sensorValue += analogRead(sensorPin);
        
        sensorValue /= 100;
        
        int angle = (int)(sensorValue / 1024.0 * 280);
        
        if(abs(angle - lastAngle) > 1){
            String txtMsg = String(angle) + "\r\n";  
            char buf[txtMsg.length()];
            txtMsg.toCharArray(buf, txtMsg.length());
            server.write(buf, txtMsg.length());
            Serial.println(txtMsg);
            
            lastAngle = angle;
            //delay(300);
        }
    }
}

User Interface (remote_gauge.php)

PHP
<!DOCTYPE html>
<html>
<head>
<title>PHPoC Shield / <?echo system("uname -i")?></title>
<meta name="viewport" content="width=device-width, initial-scale=0.7">
<style> body { text-align: center; } </style>
<script>
var canvas_width = 450, canvas_height = 450;
var pivot_x = canvas_width/2, pivot_y = canvas_height/2;
var pivot_radius = 7;
var hand_radius = 95, hand_max_angle = 280;
var ws;

function init()
{
	var gage = document.getElementById("gage_01");
	var ctx = gage.getContext("2d");

	gage.width = canvas_width;
	gage.height = canvas_height;

	ctx.translate(pivot_x, pivot_y);
	ctx.rotate(130 / 180 * Math.PI);
	ctx.shadowColor = "LightGray";
	
	update_view(0);
}
function connect_onclick()
{
	if(ws == null)
	{
		ws = new WebSocket("ws://<?echo _SERVER("HTTP_HOST")?>/gauge", "text.phpoc");
		document.getElementById("ws_state").innerHTML = "CONNECTING";
		ws.onopen = ws_onopen;
		ws.onclose = ws_onclose;
		ws.onmessage = ws_onmessage;

		ws.onmessage = ws_onmessage;
	}
	else
		ws.close();
}
function ws_onopen()
{
	document.getElementById("ws_state").innerHTML = "<font color='blue'>CONNECTED</font>";
	document.getElementById("bt_connect").innerHTML = "Disconnect";
	ws.send("B\r\n");
}
function ws_onclose()
{
	document.getElementById("ws_state").innerHTML = "<font color='gray'>CLOSED</font>";
	document.getElementById("bt_connect").innerHTML = "Connect";
	ws.onopen = null;
	ws.onclose = null;
	ws.onmessage = null;
	ws = null;
}
function ws_onmessage(e_msg)
{
	e_msg = e_msg || window.event; // MessageEvent

	var angle = parseInt(e_msg.data);
	console.log(angle);

	update_view(angle);
}
function update_view(angle)
{
	var gage = document.getElementById("gage_01");
	var ctx = gage.getContext("2d");
	var text;

	if((angle < 0) || (angle > hand_max_angle))
		return;
	
	ctx.shadowBlur = 15;
	ctx.fillStyle = "#808080";
	ctx.beginPath();
	ctx.arc(0, 0, 215, 0, 2* Math.PI);
	ctx.fill();
	
	ctx.fillStyle = "#808080";
	ctx.strokeStyle = "#bfbfbf";
	ctx.lineWidth = 3;
	ctx.beginPath();
	ctx.arc(0, 0, 200, 0, 2* Math.PI);
	ctx.fill();
	ctx.stroke();
	
	ctx.shadowBlur = 1;
	ctx.fillStyle = "#383330";
	ctx.beginPath();
	ctx.arc(0, 0, 180, 0, 2* Math.PI);
	ctx.fill();
	
	ctx.fillStyle = "black";
	ctx.beginPath();
	ctx.arc(0, 0, 165, 0, 2* Math.PI);
	ctx.fill();
	
	ctx.strokeStyle = "white";
	ctx.fillStyle = "white";
	ctx.shadowBlur = 20;
	ctx.shadowColor = "white";
	ctx.save();
	
	ctx.lineWidth = 10;
	for(var i = 0; i < 5; i++)
	{
		ctx.beginPath();
		ctx.lineTo(hand_radius + 12, 0);
		ctx.lineTo(hand_radius + 50, 0);
		ctx.stroke();
		ctx.rotate(70 / 180 * Math.PI);
	}
	ctx.restore();
	ctx.save();
	ctx.rotate(35 / 180 * Math.PI);
	ctx.lineWidth = 8;
	for(var i = 0; i < 4; i++)
	{
		ctx.beginPath();
		ctx.lineTo(hand_radius + 12, 0);
		ctx.lineTo(hand_radius + 40, 0);
		ctx.stroke();
		ctx.rotate(70 / 180 * Math.PI);
	}
	ctx.restore();
	ctx.save();
	ctx.rotate( 17.5 / 180 * Math.PI);
	ctx.lineWidth = 7;
	for(var i = 0; i < 8; i++)
	{
		ctx.beginPath();
		ctx.lineTo(hand_radius + 12, 0);
		ctx.lineTo(hand_radius + 35, 0);
		ctx.stroke();
		ctx.rotate(35 / 180 * Math.PI);
	}
	
	ctx.restore();
	ctx.lineCap = "round";
	ctx.lineWidth = 7;
	
	ctx.rotate(angle / 180 * Math.PI);
	ctx.beginPath();
	ctx.lineTo(0, 0);
	ctx.lineTo(hand_radius, 0);
	ctx.stroke();
	ctx.rotate(-angle / 180 * Math.PI);
	
	ctx.beginPath();
	ctx.arc(0, 0, 10, 0, 2* Math.PI);
	ctx.fill();
	
	ctx.rotate(-130 / 180 * Math.PI);
	ctx.font = "24px Arial";
	ctx.textAlign = "center";
	ctx.fillText(angle + "°", 0, 50);
	ctx.rotate(130 / 180 * Math.PI);
}
window.onload = init;
</script>
</head>
<body>

<h2>
Arduino - Dynamic Gauge<br>

<canvas id="gage_01"></canvas>

<p>
WebSocket : <span id="ws_state">null</span><br>
</p>
<button id="bt_connect" type="button" onclick="connect_onclick();">Connect</button>
</h2>

</body>
</html>

Credits

IoT_lover
10 projects • 192 followers

Comments

Related channels and tags
  • Arduino
  • DIYables
  • PHPoC