read encoder (motor axis speed)

hello,

I have an DC motor which is provided with an encoder, this encoder should give a number of pulses per rotation, the encoder provides four pulses per rotation. The maximum motor speed is 1500rpm so this is 25 Hz. The encoder gives 100 pulses a second on this speed.

My question is, does anyone have a simple program to read these pulses on the arduino uno? Do I need to read those pulses with a interrupt? How do I do it? I don't have to know the position and the direction of the axis, I only need te speed of it.

When I have the speed of the axis in pulses/second I use the speed for a PID regulator on the arduino controller.

thx

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Catwell over 13 years ago +1

Jeroen, This is easy, start here: http://arduino.cc/playground/Main/RotaryEncoders What is the current draw on the motor? Cabe http://twitter.com/Cabe_e14

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0 DAB over 13 years ago

Hi Jeroen,

Most encoders use a byphase Quadrature encoding so you get both position increments and direction of rotation. You can use a simple circuit to convert it to pulse and direction inputs.

DAB
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0 billabott over 13 years ago in reply to DAB

Is the encoder an electrically separate part of the motor assembly? I assume it requires 4 wires: Vcc, Ground, S1, and S2.
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0 Former Member over 13 years ago in reply to billabott

thx for the reply!

the encoder is a 4 wire encoder, Vcc, GND, A-,B- chanal.
I think that this program wil count the pulses every half a second.

const int Encoder_Pin = 2; // output of encoder to interrupt #0, pin 2 of arduino
int Encoder_Count = 0;
long Time1 = 0;
long Time2 = 0;
long Time3 = 0;

void setup()
{

Serial.begin(9600);
attachInterrupt(0, Count_Pulses, FALLING); //attach interrupt to encoder pin
}

void Count_Pulses()
{
//this is the function that runs every time pin 2
//switches from high to low
Encoder_Count++;
}

void loop()
{
Time1 = millis();
Time3 = Time1 -= Time2;

if (Time3 >= 500)
{

   Time2 = millis ();
   int PulsSpeed = Encoder_Count;
   Encoder_Count = 0;
   Serial.println(PulsSpeed);

}
}
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0 Former Member over 13 years ago in reply to billabott

thx for the reply!

the encoder is a 4 wire encoder, Vcc, GND, A-,B- chanal.
I think that this program wil count the pulses every half a second.

const int Encoder_Pin = 2; // output of encoder to interrupt #0, pin 2 of arduino
int Encoder_Count = 0;
long Time1 = 0;
long Time2 = 0;
long Time3 = 0;

void setup()
{

Serial.begin(9600);
attachInterrupt(0, Count_Pulses, FALLING); //attach interrupt to encoder pin
}

void Count_Pulses()
{
//this is the function that runs every time pin 2
//switches from high to low
Encoder_Count++;
}

void loop()
{
Time1 = millis();
Time3 = Time1 -= Time2;

if (Time3 >= 500)
{

   Time2 = millis ();
   int PulsSpeed = Encoder_Count;
   Encoder_Count = 0;
   Serial.println(PulsSpeed);

}
}
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