From 9a23407b4c169fa862a95989ed4d274d1623a1bc Mon Sep 17 00:00:00 2001
From: Peter Wu <peter@lekensteyn.nl>
Date: Wed, 17 Jun 2015 14:54:55 +0200
Subject: Attempt to explain timerTurret.

BUG: timerTurret is never reset to 0 once -1.
---
 Venus_Skeleton/Venus_Skeleton.ino | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/Venus_Skeleton/Venus_Skeleton.ino b/Venus_Skeleton/Venus_Skeleton.ino
index 14e1ae8..e50709f 100644
--- a/Venus_Skeleton/Venus_Skeleton.ino
+++ b/Venus_Skeleton/Venus_Skeleton.ino
@@ -105,7 +105,16 @@ int currValDirectionDegree = 0;
 unsigned long timerMovementStart = 0;
 unsigned long timerMovementStop = 0;
 //unsigned long timerInitialSequence = 0; // TODO unused?
+/**
+ * If set to 0, then the turret is not rotating and in a stable position.
+ * Else the turret is apparently rotating and cannot be stopped.
+ */
 unsigned long timerTurret = 0;
+/**
+ * Always read the sensors on the turret, unless disabled (for example, when
+ * the measurements become unreliable due to a rotating robot).
+ */
+bool turretSensingEnabled = true;
 
 // Counters
 int counterInit = 0;
@@ -308,7 +317,7 @@ void sensObstacleTurret() {
 	// BE AWARE, LOCALISATION OF OBSTACLE IS y DISTANCE FROM CENTER OF ROBOT 
 	// (creates triangle with centerOfRobot, centerOfSensor and Obstacle as its corners)
 	
-	if (timerTurret == 0) {
+	if (turretSensingEnabled && timerTurret == 0) {
 		long distance = sensPing(PIN_SENS_OBSTACLE_TURRET);
 		if (data.obstacle_turret_distances[counterTurret] != distance) {
 			data.obstacle_turret_distances[counterTurret] = distance;
@@ -349,7 +358,7 @@ void sensSampleTurret() {
 	// BE AWARE, LOCALISATION OF OBSTACLE IS y DISTANCE FROM CENTER OF ROBOT 
 	// (creates triangle with centerOfRobot, centerOfSensor and Obstacle as its corners)
 	
-	if (timerTurret == 0) {
+	if (turretSensingEnabled && timerTurret == 0) {
 		int i;
 		bool sample = false;
 		
@@ -402,7 +411,7 @@ void sensBeaconTurret() {
 	// BE AWARE, LOCALISATION OF OBSTACLE IS y DISTANCE FROM CENTER OF ROBOT 
 	// (creates triangle with centerOfRobot, centerOfSensor and Obstacle as its corners)
 	
-	if (timerTurret == 0) {
+	if (turretSensingEnabled && timerTurret == 0) {
 		bool beacon;
 		
 		beacon = sensIRRemote(); // SENSORDATA HERE
@@ -470,8 +479,9 @@ bool moveTurnTo(int degree) {
 		return true;
 	}
 	
-	// Make sure turret doesn't move
-	timerTurret = 1;
+	// when rotating, the data collected with sensors on the turret becomes
+	// useless as the orientation is not fixed.
+	turretSensingEnabled = false;
 	
 	// if movementtimer is not started, start timer or something and initiate movement
 	// else continue movement and return false
@@ -512,9 +522,15 @@ bool moveTurnTo(int degree) {
 	if (timerMovementStop < millis()) {
 		DEBUG_PRINT("\n  Stop turn move")
 		stopMovement();
+
+		// reset the ultrasound measurements
 		for (int k = 0; k < NUM_TURRET_DIRECTIONS; k++) {
 			data.obstacle_turret_distances[k] = OBSTACLE_FAR_AWAY;
 		}
+
+		// allow the sensors to be read out again
+		turretSensingEnabled = true;
+
 		// rotation is completed.
 		return true;
 	}
@@ -581,6 +597,7 @@ void turnTurretToNext() {
 		timerTurret = millis();
 		turnTurretTo(deg);
 	}
+	// If the turret is finished with rotating, mark it as idle.
 	if ((timerTurret + 100) < millis()) {
 		timerTurret = 0;
 	}
-- 
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