Build Instructions

Collapse

• 1

  Run a Program

  #include
  LiquidCrystal lcd(A5,A4,A3,A2,A1,A0);
  #include
  const int stepsPerRevolution = 200; // change this to fit the number of steps per revolution
  Stepper myStepper(stepsPerRevolution, 8, 9, 10, 11);
  volatile byte REV;
  unsigned long int rpm,RPM;
  unsigned long st=0;
  unsigned long time;
  int ledPin = 13;
  int led = 0,RPMlen , prevRPM;
  int flag = 0;

  int flag1=1;
  #define bladesInFan 2
  float radius=4.7; // inch
  int preSteps=0;
  float stepAngle= 360.0/(float)stepsPerRevolution;
  float minSpeed=0;
  float maxSpeed=280.0;
  float minSteps=0;
  float maxSteps=maxSpeed/stepAngle;

  void setup()
  {
  myStepper.setSpeed(60);
  Serial.begin(9600);
  pinMode(ledPin, OUTPUT);
  lcd.begin(16,2);
  lcd.print("Speedometer");
  delay(2000);
  attachInterrupt(0, RPMCount, RISING);
  }

  void loop()
  {
  readRPM();
  radius=((radius * 2.54)/100.0); // convering in meter
  int Speed= ((float)RPM * 60.0 * (2.0 * 3.14 * radius)/1000.0);
  // RPM in 60 minute, diameter of tyre (2pi r) r is radius, 1000 to convert in km
  int Steps=map(Speed, minSpeed,maxSpeed,minSteps,maxSteps);
  
  if(flag1)
  {
  Serial.print(Speed);
  Serial.println("Kmh");
  lcd.setCursor(0,0);
  lcd.print("RPM: ");
  lcd.print(RPM);
  lcd.print(" ");
  lcd.setCursor(0,1);
  lcd.print("Speed: ");
  lcd.print(Speed);
  lcd.print(" Km/h ");
  flag1=0;
  }
  int currSteps=Steps;
  int steps= currSteps-preSteps;
  preSteps=currSteps;
  myStepper.step(steps);
  }

  int readRPM()
  {
  if(REV >= 10 or millis()>=st+1000) // IT WILL UPDATE AFETR EVERY 10 READINGS or 1 second in idle
  {
  if(flag==0)
  flag=1;
  rpm = (60/2)*(1000/(millis() - time))*REV/bladesInFan;
  time = millis();
  REV = 0;
  int x= rpm;
  while(x!=0)
  {
  x = x/10;
  RPMlen++;
  }
  Serial.println(rpm,DEC);
  RPM=rpm;
  delay(500);
  st=millis();
  flag1=1;
  }
  }

  void RPMCount()
  {
  REV++;
  if (led == LOW)
  {
  led = HIGH;
  }
  else
  {
  led = LOW;
  }
  digitalWrite(ledPin, led);
  }

View all instructions