Arduino based RPM counter with a new and faster algorithm

This project makes use of the preciseness of a laser beam, just one IR sensor and that good old arduino board to measure the RPM of motors.

Apr 30, 2020

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60280 views

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9 respects

environmental sensing

data collection

Components and supplies

USB-A to Mini-USB Cable

Jumper wires (generic)

Laser Diode, 655 nm

IR proximity sensor

Arduino UNO

DC motor (generic)

Battery, 9 V

Tools and machines

Solder Wire, Lead Free

Soldering iron (generic)

Apps and platforms

Arduino IDE

Project description

Code

RPM_counter_101

arduino

This is the code for the RPM counter.

1//code by YaSh.
2
3int sen = A0;
4const float wid = 0.012;   //adjust   the width of the fan blade according to your needs.
5const float rad = 0.045;    //adjust the radius of the point of detection in the fan blade.
6const float   konst = 6.2832;  //  2*pi.
7float time_1;
8float time_2;
9float vel;
10float   diff;
11float tnet;
12float rpm;
13void setup() 
14{
15  Serial.begin(9600);
16   pinMode(sen,INPUT);
17  Serial.print(" \
18 please start the motor at least 3   seconds prior.\
19");
20  delay(3000);
21}
22void loop()
23{
24  if(analogRead(sen)<950)
25   {
26    time_1 = millis();
27    delay(30);
28  }
29  if(analogRead(sen)>950)
30   {
31    time_2 = millis();
32    diff = (time_2-time_1);         
33    vel   = wid/diff;                      //rotation velocity
34    tnet = (konst*rad)/vel;               //time = (2*pi*radius)/velocity.
35    rpm = (60000)/tnet;                //   time in ms to minutes and then to rpm conversion step.
36  }
37Serial.print("\
38   The rpm is : "); 
39Serial.println( rpm );
40}

//code by YaSh.

int sen = A0;
const float wid = 0.012;   //adjust   the width of the fan blade according to your needs.
const float rad = 0.045;    //adjust the radius of the point of detection in the fan blade.
const float   konst = 6.2832;  //  2*pi.
float time_1;
float time_2;
float vel;
float   diff;
float tnet;
float rpm;
void setup() 
{
  Serial.begin(9600);
   pinMode(sen,INPUT);
  Serial.print(" \
 please start the motor at least 3   seconds prior.\
");
  delay(3000);
}
void loop()
{
  if(analogRead(sen)<950)
   {
    time_1 = millis();
    delay(30);
  }
  if(analogRead(sen)>950)
   {
    time_2 = millis();
    diff = (time_2-time_1);         
    vel   = wid/diff;                      //rotation velocity
    tnet = (konst*rad)/vel;               //time = (2*pi*radius)/velocity.
    rpm = (60000)/tnet;                //   time in ms to minutes and then to rpm conversion step.
  }
Serial.print("\
   The rpm is : "); 
Serial.println( rpm );
}

RPM_counter_101

arduino

This is the code for the RPM counter.

1//code by YaSh.
2
3int sen = A0;
4const float wid = 0.012;   //adjust  the width of the fan blade according to your needs.
5const float rad = 0.045;   //adjust the radius of the point of detection in the fan blade.
6const float  konst = 6.2832;  //  2*pi.
7float time_1;
8float time_2;
9float vel;
10float  diff;
11float tnet;
12float rpm;
13void setup() 
14{
15  Serial.begin(9600);
16  pinMode(sen,INPUT);
17  Serial.print(" \
18 please start the motor at least 3  seconds prior.\
19");
20  delay(3000);
21}
22void loop()
23{
24  if(analogRead(sen)<950)
25  {
26    time_1 = millis();
27    delay(30);
28  }
29  if(analogRead(sen)>950)
30  {
31    time_2 = millis();
32    diff = (time_2-time_1);         
33    vel  = wid/diff;                      //rotation velocity
34    tnet = (konst*rad)/vel;              //time = (2*pi*radius)/velocity.
35    rpm = (60000)/tnet;                //  time in ms to minutes and then to rpm conversion step.
36  }
37Serial.print("\
38  The rpm is : "); 
39Serial.println( rpm );
40}

//code by YaSh.

int sen = A0;
const float wid = 0.012;   //adjust  the width of the fan blade according to your needs.
const float rad = 0.045;   //adjust the radius of the point of detection in the fan blade.
const float  konst = 6.2832;  //  2*pi.
float time_1;
float time_2;
float vel;
float  diff;
float tnet;
float rpm;
void setup() 
{
  Serial.begin(9600);
  pinMode(sen,INPUT);
  Serial.print(" \
 please start the motor at least 3  seconds prior.\
");
  delay(3000);
}
void loop()
{
  if(analogRead(sen)<950)
  {
    time_1 = millis();
    delay(30);
  }
  if(analogRead(sen)>950)
  {
    time_2 = millis();
    diff = (time_2-time_1);         
    vel  = wid/diff;                      //rotation velocity
    tnet = (konst*rad)/vel;              //time = (2*pi*radius)/velocity.
    rpm = (60000)/tnet;                //  time in ms to minutes and then to rpm conversion step.
  }
Serial.print("\
  The rpm is : "); 
Serial.println( rpm );
}

Downloadable files

Circuit Schematics

schematic for connecting sensor to the arduino board

Circuit Schematics