/*
  This code measures the speed of a motor connected to an Arduino Uno 
  using a speed sensor module.

  Board: Arduino Uno R4 (or R3)
  Component: Speed Sensor Module
*/

// Define the sensor and motor pins
volatile int sensorPin = 2;
const int motorB_1A = 9;
const int motorB_2A = 10;
int Speed;
int PWMSpeed;
int PWMSpeedRamp = 12;
int flag = 0;
volatile int count = 0;

// Define variables for measuring speed


void setup() {
  Serial.begin(9600);

  pinMode(sensorPin, INPUT_PULLUP);   // set sensor pin as input
  pinMode(motorB_1A, OUTPUT);  // set motor pin 1 as output
  pinMode(motorB_2A, OUTPUT);  // set motor pin 2 as output
  attachInterrupt(digitalPinToInterrupt(sensorPin), blink1, FALLING);
  analogWrite(motorB_1A, 0);  // set motor speed
  analogWrite(motorB_2A, 0);
  pinMode(A0, INPUT);
}

void loop() {
  
  
  PWMSpeed = (analogRead(A0)/1023.00)*255;
  Speed = (PWMSpeed*100)/255;

if (PWMSpeedRamp < PWMSpeed){
  ++PWMSpeedRamp;
}
if (PWMSpeedRamp >  PWMSpeed){
  --PWMSpeedRamp;
}



  Serial.print(PWMSpeed);
  Serial.print("  ");
  Serial.print(PWMSpeedRamp);
  Serial.print("  ");
  Serial.println(count);
  
  
  if ((count >= 0) && (count <399)){
    analogWrite(motorB_1A, PWMSpeedRamp);
  }
if ((count >= 460)&& (count <499)){
  
  analogWrite(motorB_1A, 20);
   
}
  
  if (count >=500){
    analogWrite(motorB_1A, 0);
    count = 0;
    delay (3000);
    PWMSpeedRamp = 12;
    flag = 0;
  }
}
  void blink1(){
    
    count = count + 1;
  }