Datasheet

Using feedback in your code

Now that we have a calibrated feedback signal, we can easily convert between servo position

and feedback voltages in our code.

Seeking to a position

The following bit of code will seek to a position and return as soon as we reach it. There is no

need to add an arbitrary delay to the code because the feedback signal will tell us exactly when

we get there!

int maxFeedback;

int tolerance = 2; // max feedback measurement error

This function establishes the feedback values for 2 positions of the servo.

With this information, we can interpolate feedback values for intermediate positions

void calibrate(Servo servo, int analogPin, int minPos, int maxPos)

{

// Move to the minimum position and record the feedback value

servo.write(minPos);

minDegrees = minPos;

delay(2000); // make sure it has time to get there and settle

minFeedback = analogRead(analogPin);

// Move to the maximum position and record the feedback value

servo.write(maxPos);

maxDegrees = maxPos;

delay(2000); // make sure it has time to get there and settle

maxFeedback = analogRead(analogPin);

}

void setup()

{

myservo.attach(servoPin);

calibrate(myservo, feedbackPin, 20, 160); // calibrate for the 20-160 degree range

}

void loop()

{

}

void Seek(Servo servo, int analogPin, int pos)

{

// Start the move...

servo.write(pos);

// Calculate the target feedback value for the final position

int target = map(pos, minDegrees, maxDegrees, minFeedback, maxFeedback);

// Wait until it reaches the target

while(abs(analogRead(analogPin) - target) > tolerance){} // wait...