Completed artf2662: removed Start()/Stop() in Encoders and Counters.

Change-Id: I11954bb5f66e54461455637d79013c1071f5d00f

wpilibj/wpilibJavaDevices/src/main/java/edu/wpi/first/wpilibj/Counter.java

@@ -24,6 +24,9 @@ import edu.wpi.first.wpilibj.util.BoundaryException;
  * general purpose class for counting repetitive events. It can return the
  * number of counts, the period of the most recent cycle, and detect when the
  * signal being counted has stopped by supplying a maximum cycle time.
+ *
+ * All counters will immediately start counting - reset() them if you need them
+ * to be zeroed before use.
  */
 public class Counter extends SensorBase implements CounterBase,
 		LiveWindowSendable, PIDSource {
@@ -91,12 +94,19 @@ public class Counter extends SensorBase implements CounterBase,
 
 		UsageReporting.report(tResourceType.kResourceType_Counter, m_index,
 				mode.value);
+
+		status = ByteBuffer.allocateDirect(4);
+		status.order(ByteOrder.LITTLE_ENDIAN);
+		CounterJNI.startCounter(m_counter, status.asIntBuffer());
+		HALUtil.checkStatus(status.asIntBuffer());
 	}
 
 	/**
 	 * Create an instance of a counter where no sources are selected. Then they
 	 * all must be selected by calling functions to specify the upsource and the
 	 * downsource independently.
+	 *
+	 * The counter will start counting immediately.
 	 */
 	public Counter() {
 		initCounter(Mode.kTwoPulse);
@@ -107,6 +117,8 @@ public class Counter extends SensorBase implements CounterBase,
 	 * existing digital input is to be shared by multiple other objects such as
 	 * encoders.
 	 *
+	 * The counter will start counting immediately.
+	 *
 	 * @param source
 	 *            the digital source to count
 	 */
@@ -121,6 +133,8 @@ public class Counter extends SensorBase implements CounterBase,
 	 * Create an instance of a Counter object. Create an up-Counter instance
 	 * given a channel.
 	 *
+	 * The counter will start counting immediately.
+	 *
 	 * @param channel
 	 *            the digital input channel to count
 	 */
@@ -134,6 +148,8 @@ public class Counter extends SensorBase implements CounterBase,
 	 * up-Counter given an analog trigger. Use the trigger state output from the
 	 * analog trigger.
 	 *
+	 * The counter will start counting immediately.
+	 *
 	 * @param encodingType
 	 *            which edges to count
 	 * @param upSource
@@ -175,6 +191,8 @@ public class Counter extends SensorBase implements CounterBase,
 	 * up-Counter given an analog trigger. Use the trigger state output from the
 	 * analog trigger.
 	 *
+	 * The counter will start counting immediately.
+	 *
 	 * @param trigger
 	 *            the analog trigger to count
 	 */
@@ -422,18 +440,6 @@ public class Counter extends SensorBase implements CounterBase,
 		HALUtil.checkStatus(status.asIntBuffer());
 	}
 
-	/**
-	 * Start the Counter counting. This enables the counter and it starts
-	 * accumulating counts from the associated input channel. The counter value
-	 * is not reset on starting, and still has the previous value.
-	 */
-	public void start() {
-		ByteBuffer status = ByteBuffer.allocateDirect(4);
-		status.order(ByteOrder.LITTLE_ENDIAN);
-		CounterJNI.startCounter(m_counter, status.asIntBuffer());
-		HALUtil.checkStatus(status.asIntBuffer());
-	}
-
 	/**
 	 * Read the current counter value. Read the value at this instant. It may
 	 * still be running, so it reflects the current value. Next time it is read,
@@ -469,17 +475,6 @@ public class Counter extends SensorBase implements CounterBase,
 		HALUtil.checkStatus(status.asIntBuffer());
 	}
 
-	/**
-	 * Stop the Counter. Stops the counting but doesn't effect the current
-	 * value.
-	 */
-	public void stop() {
-		ByteBuffer status = ByteBuffer.allocateDirect(4);
-		status.order(ByteOrder.LITTLE_ENDIAN);
-		CounterJNI.stopCounter(m_counter, status.asIntBuffer());
-		HALUtil.checkStatus(status.asIntBuffer());
-	}
-
 	/**
 	 * Set the maximum period where the device is still considered "moving".
 	 * Sets the maximum period where the device is considered moving. This value

wpilibj/wpilibJavaDevices/src/main/java/edu/wpi/first/wpilibj/CounterBase.java

@@ -11,6 +11,9 @@ package edu.wpi.first.wpilibj;
  * Interface for counting the number of ticks on a digital input channel.
  * Encoders, Gear tooth sensors, and counters should all subclass this so it can be used to
  * build more advanced classes for control and driving.
+ *
+ * All counters will immediately start counting - reset() them if you need them
+ * to be zeroed before use.
  */
 public interface CounterBase {
 
@@ -44,11 +47,6 @@ public interface CounterBase {
         }
     }
 
-    /**
-     * Start the counter
-     */
-    public void start();
-
     /**
      * Get the count
      * @return the count
@@ -60,11 +58,6 @@ public interface CounterBase {
      */
     void reset();
 
-    /**
-     * Stop counting
-     */
-    void stop();
-
     /**
      * Get the time between the last two edges counted
      * @return the time beteween the last two ticks in seconds

wpilibj/wpilibJavaDevices/src/main/java/edu/wpi/first/wpilibj/Encoder.java

@@ -28,6 +28,9 @@ import edu.wpi.first.wpilibj.util.BoundaryException;
  * mounted such that forward movement generates negative values. Quadrature
  * encoders have two digital outputs, an A Channel and a B Channel that are out
  * of phase with each other to allow the FPGA to do direction sensing.
+ *
+ * All encoders will immediately start counting - reset() them if you need them
+ * to be zeroed before use.
  */
 public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveWindowSendable {
 
@@ -58,6 +61,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	 * Common initialization code for Encoders. This code allocates resources
 	 * for Encoders and is common to all constructors.
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param reverseDirection
 	 *            If true, counts down instead of up (this is all relative)
 	 * @param encodingType
@@ -102,11 +107,21 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 		UsageReporting.report(tResourceType.kResourceType_Encoder,
 				m_index, m_encodingType.value);
 		LiveWindow.addSensor("Encoder", m_aSource.getChannelForRouting(), this);
+
+		if (m_counter == null) {
+			ByteBuffer status = ByteBuffer.allocateDirect(4);
+			// set the byte order
+			status.order(ByteOrder.LITTLE_ENDIAN);
+			EncoderJNI.startEncoder(m_encoder, status.asIntBuffer());
+			HALUtil.checkStatus(status.asIntBuffer());
+		}
 	}
 
 	/**
 	 * Encoder constructor. Construct a Encoder given a and b channels.
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aChannel
 	 *            The a channel digital input channel.
 	 * @param bChannel
@@ -129,6 +144,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	/**
 	 * Encoder constructor. Construct a Encoder given a and b channels.
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aChannel
 	 *            The a channel digital input channel.
 	 * @param bChannel
@@ -141,6 +158,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	/**
 	 * Encoder constructor. Construct a Encoder given a and b channels.
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aChannel
 	 *            The a channel digital input channel.
 	 * @param bChannel
@@ -175,6 +194,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	 * Encoder constructor. Construct a Encoder given a and b channels.
 	 * Using an index pulse forces 4x encoding
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aChannel
 	 *            The a channel digital input channel.
 	 * @param bChannel
@@ -201,6 +222,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	 * Encoder constructor. Construct a Encoder given a and b channels.
 	 * Using an index pulse forces 4x encoding
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aChannel
 	 *            The a channel digital input channel.
 	 * @param bChannel
@@ -219,6 +242,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	 * shared. The Encoder class will not allocate the digital inputs and assume
 	 * that they already are counted.
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aSource
 	 *            The source that should be used for the a channel.
 	 * @param bSource
@@ -248,6 +273,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	 * shared. The Encoder class will not allocate the digital inputs and assume
 	 * that they already are counted.
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aSource
 	 *            The source that should be used for the a channel.
 	 * @param bSource
@@ -263,6 +290,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	 * shared. The Encoder class will not allocate the digital inputs and assume
 	 * that they already are counted.
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aSource
 	 *            The source that should be used for the a channel.
 	 * @param bSource
@@ -304,6 +333,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	 * shared. The Encoder class will not allocate the digital inputs and assume
 	 * that they already are counted.
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aSource
 	 *            The source that should be used for the a channel.
 	 * @param bSource
@@ -337,6 +368,8 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 	 * shared. The Encoder class will not allocate the digital inputs and assume
 	 * that they already are counted.
 	 *
+	 * The encoder will start counting immediately.
+	 *
 	 * @param aSource
 	 *            The source that should be used for the a channel.
 	 * @param bSource
@@ -378,36 +411,6 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, LiveW
 		}
 	}
 
-	/**
-	 * Start the Encoder. Starts counting pulses on the Encoder device.
-	 */
-	public void start() {
-		if (m_counter != null) {
-			m_counter.start();
-		} else {
-			ByteBuffer status = ByteBuffer.allocateDirect(4);
-			// set the byte order
-			status.order(ByteOrder.LITTLE_ENDIAN);
-			EncoderJNI.startEncoder(m_encoder, status.asIntBuffer());
-			HALUtil.checkStatus(status.asIntBuffer());
-		}
-	}
-
-	/**
-	 * Stops counting pulses on the Encoder device. The value is not changed.
-	 */
-	public void stop() {
-		if (m_counter != null) {
-			m_counter.stop();
-		} else {
-			ByteBuffer status = ByteBuffer.allocateDirect(4);
-			// set the byte order
-			status.order(ByteOrder.LITTLE_ENDIAN);
-			EncoderJNI.stopEncoder(m_encoder, status.asIntBuffer());
-			HALUtil.checkStatus(status.asIntBuffer());
-		}
-	}
-
 	/**
 	 * Gets the raw value from the encoder. The raw value is the actual count
 	 * unscaled by the 1x, 2x, or 4x scale factor.

wpilibj/wpilibJavaDevices/src/main/java/edu/wpi/first/wpilibj/Ultrasonic.java

@@ -125,7 +125,6 @@ public class Ultrasonic extends SensorBase implements PIDSource, LiveWindowSenda
 		m_counter.setMaxPeriod(1.0);
 		m_counter.setSemiPeriodMode(true);
 		m_counter.reset();
-		m_counter.start();
 		m_enabled = true; // make it available for round robin scheduling
 		setAutomaticMode(originalMode);