Speedometer Code in JavaScript

This JavaScript code snippet helps you to create an animated speedometer to indicate speed. The speedometer display speed in both analog and digital format. The interface is inspired by the Tesla speedometer that is built with HTML5 canvas and JavaScript. You can set a custom speed and change the size of the speedometer according to your needs.

How to Create Speedometer in JavaScript

1. First of all, create a canvas element with an id “canvas” and place it where you want to display the speedometer.

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

2. After that, define the CSS styles for the canvas element as follows:

canvas {
  margin: 0 auto;
  display: block;
}

3. Finally, add the following JavaScript code and done.

'use strict';
/*
* TESLA HUD BY Tameem Imamdad timamdad@hawk.iit.edu
GitHub: https://github.com/tameemi/tesla-speedometer
*/

let dev = false;
//let t0 = 0;
//let t1 = 0;

     var c = document.getElementById("canvas");
        c.width = 500;
        c.height = 500;

        var ctx = c.getContext("2d");

        //Rescale the size
        ctx.scale(1,1);

        var speedGradient = ctx.createLinearGradient(0, 500, 0, 0);
        speedGradient.addColorStop(0, '#00b8fe');
        speedGradient.addColorStop(1, '#41dcf4');

        var rpmGradient = ctx.createLinearGradient(0, 500, 0, 0);
        rpmGradient.addColorStop(0, '#f7b733');
        rpmGradient.addColorStop(1, '#fc4a1a');
        //rpmGradient.addColorStop(1, '#EF4836');

        function speedNeedle(rotation) {
            ctx.lineWidth = 2;

            ctx.save();
            ctx.translate(250, 250);
            ctx.rotate(rotation);
            ctx.strokeRect(-130 / 2 + 170, -1 / 2, 135, 1);
            ctx.restore();

            rotation += Math.PI / 180;
        }

        function rpmNeedle(rotation) {
            ctx.lineWidth = 2;

            ctx.save();
            ctx.translate(250, 250);
            ctx.rotate(rotation);
            ctx.strokeRect(-130 / 2 + 170, -1 / 2, 135, 1);
            ctx.restore();

            rotation += Math.PI / 180;
        }

        function drawMiniNeedle(rotation, width, speed) {
            ctx.lineWidth = width;

            ctx.save();
            ctx.translate(250, 250);
            ctx.rotate(rotation);
            ctx.strokeStyle = "#333";
            ctx.fillStyle = "#333";
            ctx.strokeRect(-20 / 2 + 220, -1 / 2, 20, 1);
            ctx.restore();

            let x = (250 + 180 * Math.cos(rotation));
            let y = (250 + 180 * Math.sin(rotation));

            ctx.font = "700 20px Open Sans";
            ctx.fillText(speed, x, y);

            rotation += Math.PI / 180;
        }

        function calculateSpeedAngle(x, a, b) {
            let degree = (a - b) * (x) + b;
            let radian = (degree * Math.PI) / 180;
            return radian <= 1.45 ? radian : 1.45;
        }

        function calculateRPMAngel(x, a, b) {
            let degree = (a - b) * (x) + b;
            let radian = (degree * Math.PI) / 180;
            return radian >= -0.46153862656807704 ? radian : -0.46153862656807704;
        }

        function drawSpeedo(speed, gear, rpm, topSpeed) {
            if (speed == undefined) {
                return false;
            } else {
                speed = Math.floor(speed);
                rpm = rpm * 10;
            }

            ctx.clearRect(0, 0, 500, 500);

            ctx.beginPath();
            ctx.fillStyle = 'rgba(0, 0, 0, .9)';
            ctx.arc(250, 250, 240, 0, 2 * Math.PI);
            ctx.fill();
            ctx.save()
            ctx.restore();
            ctx.fillStyle = "#FFF";
            ctx.stroke();

            ctx.beginPath();
            ctx.strokeStyle = "#333";
            ctx.lineWidth = 10;
            ctx.arc(250, 250, 100, 0, 2 * Math.PI);
            ctx.stroke();

            ctx.beginPath();
            ctx.lineWidth = 1;
            ctx.arc(250, 250, 240, 0, 2 * Math.PI);
            ctx.stroke();

            ctx.font = "700 70px Open Sans";
            ctx.textAlign = "center";
            ctx.fillText(speed, 250, 220);

            ctx.font = "700 15px Open Sans";
            ctx.fillText("mph", 250, 235);

            if (gear == 0 && speed > 0) {
                ctx.fillStyle = "#999";
                ctx.font = "700 70px Open Sans";
                ctx.fillText('R', 250, 460);

                ctx.fillStyle = "#333";
                ctx.font = "50px Open Sans";
                ctx.fillText('N', 290, 460);
            } else if (gear == 0 && speed == 0) {
                ctx.fillStyle = "#999";
                ctx.font = "700 70px Open Sans";
                ctx.fillText('N', 250, 460);

                ctx.fillStyle = "#333";
                ctx.font = "700 50px Open Sans";
                ctx.fillText('R', 210, 460);

                ctx.font = "700 50px Open Sans";
                ctx.fillText(parseInt(gear) + 1, 290, 460);
            } else if (gear - 1 <= 0) {
                ctx.fillStyle = "#999";
                ctx.font = "700 70px Open Sans";
                ctx.fillText(gear, 250, 460);

                ctx.fillStyle = "#333";
                ctx.font = "50px Open Sans";
                ctx.fillText('R', 210, 460);

                ctx.font = "700 50px Open Sans";
                ctx.fillText(parseInt(gear) + 1, 290, 460);
            } else {
                ctx.font = "700 70px Open Sans";
                ctx.fillStyle = "#999";
                ctx.fillText(gear, 250, 460);

                ctx.font = "700 50px Open Sans";
                ctx.fillStyle = "#333";
                ctx.fillText(gear - 1, 210, 460);
                if (parseInt(gear) + 1 < 7) {
                    ctx.font = "700 50px Open Sans";
                    ctx.fillText(parseInt(gear) + 1, 290, 460);
                }
            }

            ctx.fillStyle = "#FFF";
            for (var i = 10; i <= Math.ceil(topSpeed / 20) * 20; i += 10) {
                console.log();
                drawMiniNeedle(calculateSpeedAngle(i / topSpeed, 83.07888, 34.3775) * Math.PI, i % 20 == 0 ? 3 : 1, i%20 == 0 ? i : '');
                
                if(i<=100) { 
                    drawMiniNeedle(calculateSpeedAngle(i / 47, 0, 22.9183) * Math.PI, i % 20 == 0 ? 3 : 1, i % 20 ==
                    0 ?
                    i / 10 : '');
                }
            }

            ctx.beginPath();
            ctx.strokeStyle = "#41dcf4";
            ctx.lineWidth = 25;
            ctx.shadowBlur = 20;
            ctx.shadowColor = "#00c6ff";

            ctx.strokeStyle = speedGradient;
            ctx.arc(250, 250, 228, .6 * Math.PI, calculateSpeedAngle(speed / topSpeed, 83.07888, 34.3775) * Math.PI);
            ctx.stroke();
            ctx.beginPath();
            ctx.lineWidth = 25;
            ctx.strokeStyle = rpmGradient;
            ctx.shadowBlur = 20;
            ctx.shadowColor = "#f7b733";

            ctx.arc(250, 250, 228, .4 * Math.PI, calculateRPMAngel(rpm / 4.7, 0, 22.9183) * Math.PI, true);
            ctx.stroke();
            ctx.shadowBlur = 0;


            ctx.strokeStyle = '#41dcf4';
            speedNeedle(calculateSpeedAngle(speed / topSpeed, 83.07888, 34.3775) * Math.PI);

            ctx.strokeStyle = rpmGradient;
            rpmNeedle(calculateRPMAngel(rpm / 4.7, 0, 22.9183) * Math.PI);

            ctx.strokeStyle = "#000";
        }


function setSpeed () {
  let speedM = 0;
  let gear = 0;
  let rpm = 0;
   setInterval(function(){
     if (speedM > 160){
        speedM = 0;
        rpm = 0;
      }
     if (speedM > 1 && speedM< 30){
       gear = 1;
     } else if (speedM > 30 && speedM < 50) {
       gear = 2;
          } else if (speedM > 50 &&   speedM < 70) {
       gear = 3;
     } else if (speedM > 70 &&   speedM < 100)      {
       gear = 4;
          } else if (speedM > 100)      {
       gear = 5;
     }
     
     speedM++;
     if (rpm < 1){
      rpm += .03; 
     }
        drawSpeedo(speedM,gear,rpm,160);

   }, 40);
  
}

document.addEventListener('DOMContentLoaded', function() {

    //setInterval(setSpeed, 2000)
    //renderCanvas();
  setSpeed();
    //drawSpeedo(120,4,.8,160);
}, false);

That’s all! hopefully, you have successfully integrated this speedometer code snippet into your project. If you have any questions or facing any issues, feel free to comment below.

Asif Mughal

I code and create web elements for amazing people around the world. I like work with new people. New people new Experiences.
I truly enjoy what I’m doing, which makes me more passionate about web development and coding. I am always ready to do challenging tasks whether it is about creating a custom CMS from scratch or customizing an existing system.