lejos.hardware.device.tetrix.TetrixServo Maven / Gradle / Ivy
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package lejos.hardware.device.tetrix;
import lejos.robotics.Servo;
/**
* Basic servo motor abstraction. Servos are driven by a PWM signal from the controller with varying pulse widths
* controlling the rotational position of the servo actuator shaft.
*
* The HiTechnic Servo Controller allows setting of the PWM output from 0.75 - 2.25ms. Note that some servos may hit their
* internal mechanical limits at each end of this range causing them to consume excessive current and potentially be damaged.
*
* @author Kirk P. Thompson
*/
public class TetrixServo implements Servo{
private TetrixServoController sc;
private int channel;
TetrixServo(TetrixServoController sc, int channel) {
this.sc=sc;
this.channel=channel;
}
/**
* Set the allowable pulse width operating range of this servo in microseconds and the total travel range.
* Default for pulse width at instantiation is 750 & 2250 microseconds. Default for travel is 200 degrees.
*
* The midpoint
* of the pulse width operating range should normally be 1500 microseconds so the range extents should reflect this.
*
* This information must reflect the appropriate specifications and/or empirical characterization data of the specific
* servo used for the setAngle() method to be able to position the servo accurately.
*
* @param microsecLOW The low end of the servos response/operating range in microseconds
* @param microsecHIGH The high end of the servos response/operating range in microseconds
* @param travelRange The total mechanical travel range of the servo in degrees
* @throws IllegalArgumentException if the range isn't within 750 and 2250
* @see #setAngle
*/
public void setRange (int microsecLOW, int microsecHIGH, int travelRange) throws IllegalArgumentException {
sc.setPulseRange(channel, microsecLOW, microsecHIGH, travelRange);
}
/**
* Sets the angle target of the servo. The positional accuracy of this method requires that setRange()
* be called with the
* correct parameters to establish proper ranging conversion to internal controller representation of servo position.
*
* @param angle Set servo angle in degrees.
* @see #setRange
* @see #getAngle
*/
public void setAngle(float angle){
sc.setAngle(channel, angle);
}
/**
* Returns the current servo angle as reverse calculated by the last call to setAngle(). This is calculated from the
* internal byte representation used (calculated by setAngle()) to control the servo so the resolution will be
* affected by ranging factors set with setRange()
*
* The actual physical servo position may or may not be at the reported angle if mechanical limits have been reached.
*
* @return Current servo angle
* @see #setRange
* @see #setAngle
*/
public float getAngle(){
return sc.getAngle(channel);
}
/**
* Set the PWM pulse width for the servo. This must be in the range defined for the servo. This method allows manipulation
* of the servo position based on absolute pulse widths in microseconds.
*
* A servo pulse of 1500 microseconds (1.5 ms) width will typically set the servo to its "neutral" position. This is the
* "standard pulse servo mode" used by all hobby analog servos.
*
* The HiTechic Servo Controller allows setting of the PWM output from 750 to 2250 microseconds with a step resolution
* of 5.88 microseconds (1 byte is used to control the pulse width output) and this method will calculate and use the stepped
* value closest to value passed in microSeconds.
*
Note that some servos may hit their internal mechanical limits at each end of this range causing them to consume excessive current
* and potentially be damaged.
*
* @param microSeconds The pulse width time in microseconds
* @throws IllegalArgumentException if the range isn't within 750 and 2250
* @see #setRange
*/
public void setpulseWidth(int microSeconds) throws IllegalArgumentException {
sc.setPulseWidth(channel, microSeconds);
}
public int getpulseWidth(){
return sc.getPulseWidth(channel);
}
}