User ROI

Added method to get ROI values currently being used.  Debugged errors with ROI that were causing incorrect values to be stored.  Added documentation.

Author: Grahldg

src/SparkFun_VL53L1X_Arduino_Library.cpp

@@ -251,6 +251,7 @@ uint8_t VL53L1X::getDistanceMode()
 }
 
 //Set a custom zone from the array of sensors.  Minimum of 4x4, maximum of 16x16.
+//lower left corner of the array is (0, 0) and upper right is (16, 16)
 void VL53L1X::setUserRoi(UserRoi *roi)
 {
 	uint8_t centerX = (roi->topLeftX + roi->bottomRightX + 1) / 2;
@@ -259,9 +260,9 @@ void VL53L1X::setUserRoi(UserRoi *roi)
 	uint8_t height = roi->topLeftY - roi->bottomRightY;
 
 	//Check boundary conditions, if incorrect set to default values.
-	if (width < 3 || width > 15 || height < 3 || height > 15){
+	if (width < 3 || height < 3){
 		setCenter((uint8_t)8, (uint8_t)8);
-		setZoneSize((uint8_t)15, (uint8_t)8);
+		setZoneSize((uint8_t)15, (uint8_t)15);
 	}
 	else{
 		setCenter(centerX, centerY);
@@ -272,21 +273,48 @@ void VL53L1X::setUserRoi(UserRoi *roi)
 void VL53L1X::setCenter(uint8_t centerX, uint8_t centerY){
 	uint8_t centerValue;
 
-	if (centerX > 7){
-		centerValue = 128 + (centerY << 3) + (15 - centerX);
+	if (centerY > 7){
+		centerValue = 128 + (centerX << 3) + (15 - centerY);
 	} 
 	else {
-		centerValue = ((15 - centerY) << 3) + centerX;
+		centerValue = ((15 - centerX) << 3) + centerY;
 	}
 
 	writeRegister(VL53L1_ROI_CONFIG__USER_ROI_CENTRE_SPAD , centerValue);
 }
 
 void VL53L1X::setZoneSize(uint8_t width, uint8_t height){
-	uint8_t dimensions = (height << 4) + width;
+	uint8_t dimensions = (height << 4)  + width;
 	writeRegister(VL53L1_ROI_CONFIG__USER_ROI_REQUESTED_GLOBAL_XY_SIZE, dimensions);
 }
 
+UserRoi* VL53L1X::getUserRoi(){
+	UserRoi* roi = new UserRoi();
+	
+	uint8_t center = readRegister(VL53L1_ROI_CONFIG__USER_ROI_CENTRE_SPAD);
+	uint8_t row = 0;
+	uint8_t col = 0;
+	if (center > 127){
+		row = 8 + ((255-center) & 0x07);
+		col = (center - 128) >> 3;
+	} else {
+		row = center & 0x07;
+		col = (127 - center) >> 3;
+	}
+	
+	uint8_t dimensions = readRegister(VL53L1_ROI_CONFIG__USER_ROI_REQUESTED_GLOBAL_XY_SIZE);
+	uint8_t height = dimensions >> 4;
+	uint8_t width = dimensions & 0x0F;
+
+	 
+	roi->topLeftX = (2 * col - width) >> 1;
+	roi->topLeftY = (2 * row - height) >> 1;
+	roi->bottomRightX = (2 * col + width) >> 1;
+	roi->bottomRightY = (2 * row + height) >> 1;
+	
+	return roi;
+}
+
 //The sensor returns a range status that needs to be re-mapped to one of 9 different statuses
 //This does that.
 uint8_t VL53L1X::getRangeStatus()

src/SparkFun_VL53L1X_Arduino_Library.h

@@ -109,6 +109,7 @@ class VL53L1X {
 	void setUserRoi(UserRoi*);  //Set custom sensor zones
 	void setCenter(uint8_t centerX, uint8_t centerY);  //Set the center of a custom zone
 	void setZoneSize(uint8_t width, uint8_t height);  //Set the size of a custom zone
+	UserRoi* getUserRoi();
 
   private: