Calculation of the rpm of a motor with hall effect quadrature sensor

Using Arduino Project Guidance
1

Hi friends!
I have a question. I have programmed a code that allow, without interruptions, to know if the engine turn clockwise or counterclockwise. It allows you to calculate the steps in one way and in the other way. The code is working very fine.
The code works for the motors that I show you: 6V, 210 rpm & DC.
The question: Maybe isn’t difficult (I need to improve my knowledge of Arduino computing) but I want to know the ratio of steps per second. In other words, I want to take the number steps every 1000 ms (for example) and do the next calculation:

• Time: 2513 --- step: +2380
• Time: 3515 ---step: +8543
Steps/second = (8543 – 2380) /1000.

I cannot get two measurements in two different times! Please I need your help!
I don’t need to know the exactly rpm, is enough to know the ratio of steps for second. If engine is stopped the steps/second will be 0.


motor 6v 210 rpm

//lecturas digitales
const int channelPinA = 8; //Motor RH (VERDE)
const int channelPinB = 12; //Motor RH (AMARILLO)

const int channelPinC = 7; //Motor LH (AMARILLO)
const int channelPinD = 6; //Motor LH (VERDE)

unsigned char stateChannelA;//Motor RH
unsigned char stateChannelB;//Motor RH

unsigned char stateChannelC;//Motor LH
unsigned char stateChannelD;//Motor LH

int estado_previo, estado_dos;//Motor RH
int value; //Motor RH
int prevValue; //Motor RH

int estado_previoL, estado_dosL;//Motor LH
int valueL; //Motor LH
int prevValueL; //Motor LH

const int timeThreshold = 1;
unsigned long currentTime;
unsigned long loopTime;

//Motor RH
int IN2 = 5;
int IN1 = 4;
int ENA = 3;

//motor LH
int IN3 = 11;
int IN4 = 10;
int ENB = 9;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(57600);
  pinMode(IN1, OUTPUT); //Motor RH
  pinMode(IN2, OUTPUT); //Motor RH
  pinMode(ENA, OUTPUT); //Motor RH

  pinMode(IN3, OUTPUT); //Motor LH
  pinMode(IN4, OUTPUT); //Motor LH
  pinMode(ENB, OUTPUT); //Motor LH


  pinMode(channelPinA, INPUT);
  pinMode(channelPinB, INPUT);
  currentTime = millis();
  loopTime = currentTime;
  value = 0;
}

void loop() {
  digitalWrite(IN1, LOW); //Motor RH
  digitalWrite(IN2, HIGH); //Motor RH
  analogWrite(ENA, 255); //Motor RH

  digitalWrite(IN3, LOW); //Motor LH
  digitalWrite(IN4, HIGH); //Motor LH
  analogWrite(ENB, 255); //Motor LH

  currentTime = millis();

  if (currentTime >= (loopTime + timeThreshold))
  {
    stateChannelA = digitalRead(channelPinA);
    stateChannelB = digitalRead(channelPinB);
    stateChannelC = digitalRead(channelPinC);
    stateChannelD = digitalRead(channelPinD);

//Ánalisis del motor RH
    if ((estado_previo == stateChannelB) && estado_dos != stateChannelB) {
      if ((stateChannelA == LOW) && (stateChannelB == LOW)) { //Sentido horario
        value++;
      }
      if ((stateChannelB == LOW) && (stateChannelA == HIGH)) { //Sentido antihorario
        value--;
      }
      estado_previo = stateChannelB;
    }
    if (prevValue != value)
    {
      prevValue = value;
      Serial.print("Pasos RH: ");
      Serial.println(value);
    }
  }
  if (millis - currentTime >= 1) {
    estado_dos = stateChannelB;
  }

//Ánalisis del motor LH
  if ((estado_previoL == stateChannelD) && estado_dosL != stateChannelD) {
    if ((stateChannelC == LOW) && (stateChannelD == LOW)) { //Sentido horario
      valueL++;
    }

    if ((stateChannelD == LOW) && (stateChannelC == HIGH)) { //Sentido antihorario
      valueL--;
    }
    estado_previoL = stateChannelD;
  }

  if (prevValueL != valueL)
  {
    prevValueL = valueL;
    Serial.print("Pasos LH: ");
    Serial.println(valueL);
  }

  if (millis - currentTime >= 1) {
    estado_dosL = stateChannelD;
  }
}
2

Please open your code in the Arduino IDE. Press Control-T. Repost the code after it has been auto-formatted. That formatting alone may show you what is your problem. When real coders line all their blocks up nice and neat, they don't do that just to make it pretty. It really does make it easier to read.

3

Thank you very much! Another thing that I've learned!!

//lecturas digitales
const int channelPinA = 8; //Motor RH (VERDE)
const int channelPinB = 12; //Motor RH (AMARILLO)

const int channelPinC = 7; //Motor LH (AMARILLO)
const int channelPinD = 6; //Motor LH (VERDE)

unsigned char stateChannelA;//Motor RH
unsigned char stateChannelB;//Motor RH

unsigned char stateChannelC;//Motor LH
unsigned char stateChannelD;//Motor LH

int estado_previo, estado_dos;//Motor RH
int value; //Motor RH
int prevValue; //Motor RH

int estado_previoL, estado_dosL;//Motor LH
int valueL; //Motor LH
int prevValueL; //Motor LH

const int timeThreshold = 1;
unsigned long currentTime;
unsigned long loopTime;

//Motor A
int IN2 = 5;
int IN1 = 4;
int ENA = 3;

//motor B
int IN3 = 11;
int IN4 = 10;
int ENB = 9;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(57600);
  pinMode(IN1, OUTPUT); //Motor RH
  pinMode(IN2, OUTPUT); //Motor RH
  pinMode(ENA, OUTPUT); //Motor RH

  pinMode(IN3, OUTPUT); //Motor LH
  pinMode(IN4, OUTPUT); //Motor LH
  pinMode(ENB, OUTPUT); //Motor LH


  pinMode(channelPinA, INPUT);
  pinMode(channelPinB, INPUT);
  currentTime = millis();
  loopTime = currentTime;
  value = 0;
}

void loop() {
  digitalWrite(IN1, LOW); //Motor RH
  digitalWrite(IN2, HIGH); //Motor RH
  analogWrite(ENA, 255); //Motor RH

  digitalWrite(IN3, LOW); //Motor LH
  digitalWrite(IN4, HIGH); //Motor LH
  analogWrite(ENB, 255); //Motor LH

  currentTime = millis();

  if (currentTime >= (loopTime + timeThreshold))
  {
    stateChannelA = digitalRead(channelPinA);
    stateChannelB = digitalRead(channelPinB);
    stateChannelC = digitalRead(channelPinC);
    stateChannelD = digitalRead(channelPinD);

    //Ánalisis del motor RH
    if ((estado_previo == stateChannelB) && estado_dos != stateChannelB) {
      if ((stateChannelA == LOW) && (stateChannelB == LOW)) { //Sentido horario
        value++;
      }
      if ((stateChannelB == LOW) && (stateChannelA == HIGH)) { //Sentido antihorario
        value--;
      }
      estado_previo = stateChannelB;
    }
    if (prevValue != value)
    {
      prevValue = value;
      Serial.print("Pasos RH: ");
      Serial.println(value);
    }
  }
  if (millis - currentTime >= 1) {
    estado_dos = stateChannelB;
  }



  //Ánalisis del motor LH
  if ((estado_previoL == stateChannelD) && estado_dosL != stateChannelD) {
    if ((stateChannelC == LOW) && (stateChannelD == LOW)) { //Sentido horario
      valueL++;
    }

    if ((stateChannelD == LOW) && (stateChannelC == HIGH)) { //Sentido antihorario
      valueL--;
    }
    estado_previoL = stateChannelD;
  }

  if (prevValueL != valueL)
  {
    prevValueL = valueL;
    Serial.print("Pasos LH: ");
    Serial.println(valueL);
  }

  if (millis - currentTime >= 1) {
    estado_dosL = stateChannelD;
  }

}
4 
if (millis - currentTime >= 1)

I thought you wanted one second not one millisecond. This should be 1000?

5

if (millis - currentTime >= 1)It's even worse than that (hint: (). )