Measure speed with two photoresistors

In this project I show you a simple way to measure the speed of objects passing by.

May 25, 2022

•

2134 views

•

1 respects

speed

velocity

photoresitor

Devices & Components

Arduino Mega 2560 Rev3

Resistor 10k ohm

Photo resistor

Project description

Code

arduino

1void setup(){
2  Serial.begin(9600);
3  delay(100);
4}
5
6
7void  loop(){
8  int x = analogRead(A0);
9  delayMicroseconds(100);
10  if(abs(analogRead(A0)  - x) > 2){
11    unsigned long t = micros();
12    while(1){
13      x = analogRead(A1);
14      delayMicroseconds(100);
15      if(abs(analogRead(A1) - x) > 2){
16        Serial.print(360000.0/(micros()  - t));
17        Serial.println(" km/h");
18        delay(500);
19        break;
20      }
21    }
22  }
23}

void setup(){
  Serial.begin(9600);
  delay(100);
}


void  loop(){
  int x = analogRead(A0);
  delayMicroseconds(100);
  if(abs(analogRead(A0)  - x) > 2){
    unsigned long t = micros();
    while(1){
      x = analogRead(A1);
      delayMicroseconds(100);
      if(abs(analogRead(A1) - x) > 2){
        Serial.print(360000.0/(micros()  - t));
        Serial.println(" km/h");
        delay(500);
        break;
      }
    }
  }
}

Downloadable files

Schematics

Connect everything as shown in this picture. It is very important that the two photoresistors are 10cm apart from each other. Otherwise you will get wrong speed measurements.

Schematics

Connect everything as shown in this picture. It is very important that the two photoresistors are 10cm apart from each other. Otherwise you will get wrong speed measurements.

Schematics

Comments

Only logged in users can leave comments

galoebn

0 Followers

•

0 Projects

Intro