LM393 IR speed sensor

Projects General Guidance
1

How do I measure the speed of a DC motot using LM393 IR speed sensor?

2

Please give me an arduino code that measures the speed of the DC motor using LM393 IR speed sensor and display the result in LCD.

3

Take a look at this search lots of examples to mess with
[Tachometer site:http://forum.arduino.cc](http://"Tachometer site:http://forum.arduino.cc")

4

I have looked in to this link but there is no correct solution

5

The LM393 is not a speed sensor. It can be used for that task, but only with further electronic and mechanical parts. What you need is a Rotary Encoder.

6

Dineshkannan:
I have looked in to this link but there is no correct solution

What have you created? That we can help you with?

// include the library code:
#include <LiquidCrystal.h>
 
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(8,9,4,5,6,7);
// read the hall effect sensor on pin 2
const int hallPin=2;
const int shiftLed=3;
const unsigned long sampleTime=1000;
const int maxRPM = 10200; 
void setup() 
{
  pinMode(hallPin,INPUT);
  pinMode(shiftLed,OUTPUT);
   Serial.begin(9600);
  // set up the LCD's number of rows and columns: 
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("initializing");
  delay(1000);
  lcd.clear();
}
void loop() 
{
  delay(100);
  int rpm=getRPM();
  lcd.clear();
  displayRPM(rpm);
  displayBar(rpm);
}
int getRPM()
{
  // sample for sampleTime in millisecs
  int kount=0;
  boolean kflag=LOW;
  unsigned long currentTime=0;
  unsigned long startTime=millis();
  while (currentTime<=sampleTime)
{
    if (digitalRead(hallPin)==HIGH)
{
    kflag=HIGH;
}
if (digitalRead(hallPin)==LOW && kflag==HIGH)
{
kount++;
kflag=LOW;
}
currentTime=millis()-startTime;
}
int kount2rpm = int(60000./float(sampleTime))*kount;
return kount2rpm;
}
void displayRPM(int rpm) 
{
  lcd.clear();
  // set the cursor to column 0, line 1
  lcd.setCursor(0, 0); 
  // print the number of seconds since reset:
  lcd.print(rpm,DEC);
  
  if((rpm)==60)  //change value to own choice
{
  digitalWrite(shiftLed,HIGH);
}
else if((rpm)==120)  //change value to own choice
{
  digitalWrite(shiftLed,HIGH);
}
else if((rpm)==180)  //Change value to own choice
{
  digitalWrite(shiftLed,HIGH);
}
else
{
  digitalWrite(shiftLed,LOW);
}
  lcd.setCursor(7,0);
  lcd.print("RPM");
}
void displayBar(int rpm)
{
  int numOfBars=map(rpm,0,maxRPM,0,15);
  lcd.setCursor(0,1);
  if (rpm!=0)
{
  for (int i=0; i<=numOfBars; i++)
{
 lcd.setCursor(i,1);
 lcd.write(1023);
}}}[/color]

Here's someone's code that has tachometer and LCD display
This should work perfectly with what you've given us to work with.

7

zhomeslice:
What have you created? That we can help you with?

// include the library code:

#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(8,9,4,5,6,7);
// read the hall effect sensor on pin 2
const int hallPin=2;
const int shiftLed=3;
const unsigned long sampleTime=1000;
const int maxRPM = 10200;
void setup()
{
  pinMode(hallPin,INPUT);
  pinMode(shiftLed,OUTPUT);
  Serial.begin(9600);
  // set up the LCD's number of rows and columns:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("initializing");
  delay(1000);
  lcd.clear();
}
void loop()
{
  delay(100);
  int rpm=getRPM();
  lcd.clear();
  displayRPM(rpm);
  displayBar(rpm);
}
int getRPM()
{
  // sample for sampleTime in millisecs
  int kount=0;
  boolean kflag=LOW;
  unsigned long currentTime=0;
  unsigned long startTime=millis();
  while (currentTime<=sampleTime)
{
    if (digitalRead(hallPin)==HIGH)
{
    kflag=HIGH;
}
if (digitalRead(hallPin)==LOW && kflag==HIGH)
{
kount++;
kflag=LOW;
}
currentTime=millis()-startTime;
}
int kount2rpm = int(60000./float(sampleTime))*kount;
return kount2rpm;
}
void displayRPM(int rpm)
{
  lcd.clear();
  // set the cursor to column 0, line 1
  lcd.setCursor(0, 0);
  // print the number of seconds since reset:
  lcd.print(rpm,DEC);
 
  if((rpm)==60)  //change value to own choice
{
  digitalWrite(shiftLed,HIGH);
}
else if((rpm)==120)  //change value to own choice
{
  digitalWrite(shiftLed,HIGH);
}
else if((rpm)==180)  //Change value to own choice
{
  digitalWrite(shiftLed,HIGH);
}
else
{
  digitalWrite(shiftLed,LOW);
}
  lcd.setCursor(7,0);
  lcd.print("RPM");
}
void displayBar(int rpm)
{
  int numOfBars=map(rpm,0,maxRPM,0,15);
  lcd.setCursor(0,1);
  if (rpm!=0)
{
  for (int i=0; i<=numOfBars; i++)
{
lcd.setCursor(i,1);
lcd.write(1023);
}}}[/color]




Here's someone's code that has tachometer and LCD display
This should work perfectly with what you've given us to work with.

Sorry, can give the source (?)