sensors temp compensation: use SENSOR_COUNT_MAX instead of just 3

src/modules/sensors/common.h

+/****************************************************************************
+ *
+ *   Copyright (c) 2017 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+/**
+ * @file common.h
+ * common definitions used in sensors module
+ *
+ * @author Beat Kueng <beat-kueng@gmx.net>
+ */
+
+namespace sensors
+{
+
+static const int SENSOR_COUNT_MAX = 3;
+
+} /* namespace sensors */

src/modules/sensors/temperature_compensation.cpp

@@ -54,7 +54,7 @@ int TemperatureCompensation::initialize_parameter_handles(ParameterHandles &para
 	/* rate gyro calibration parameters */
 	parameter_handles.gyro_tc_enable = param_find("TC_G_ENABLE");
 
-	for (unsigned j = 0; j < 3; j++) {
+	for (unsigned j = 0; j < SENSOR_COUNT_MAX; j++) {
 		sprintf(nbuf, "TC_G%d_ID", j);
 		parameter_handles.gyro_cal_handles[j].ID = param_find(nbuf);
 
@@ -82,7 +82,7 @@ int TemperatureCompensation::initialize_parameter_handles(ParameterHandles &para
 	/* accelerometer calibration parameters */
 	parameter_handles.accel_tc_enable = param_find("TC_A_ENABLE");
 
-	for (unsigned j = 0; j < 3; j++) {
+	for (unsigned j = 0; j < SENSOR_COUNT_MAX; j++) {
 		sprintf(nbuf, "TC_A%d_ID", j);
 		parameter_handles.accel_cal_handles[j].ID = param_find(nbuf);
 
@@ -110,7 +110,7 @@ int TemperatureCompensation::initialize_parameter_handles(ParameterHandles &para
 	/* barometer calibration parameters */
 	parameter_handles.baro_tc_enable = param_find("TC_B_ENABLE");
 
-	for (unsigned j = 0; j < 3; j++) {
+	for (unsigned j = 0; j < SENSOR_COUNT_MAX; j++) {
 		sprintf(nbuf, "TC_B%d_ID", j);
 		parameter_handles.baro_cal_handles[j].ID = param_find(nbuf);
 		sprintf(nbuf, "TC_B%d_X5", j);
@@ -152,7 +152,7 @@ int TemperatureCompensation::parameters_update()
 	/* rate gyro calibration parameters */
 	param_get(parameter_handles.gyro_tc_enable, &(_parameters.gyro_tc_enable));
 
-	for (unsigned j = 0; j < 3; j++) {
+	for (unsigned j = 0; j < SENSOR_COUNT_MAX; j++) {
 		if (param_get(parameter_handles.gyro_cal_handles[j].ID, &(_parameters.gyro_cal_data[j].ID)) == PX4_OK) {
 			param_get(parameter_handles.gyro_cal_handles[j].ref_temp, &(_parameters.gyro_cal_data[j].ref_temp));
 			param_get(parameter_handles.gyro_cal_handles[j].min_temp, &(_parameters.gyro_cal_data[j].min_temp));
@@ -183,7 +183,7 @@ int TemperatureCompensation::parameters_update()
 	/* accelerometer calibration parameters */
 	param_get(parameter_handles.accel_tc_enable, &(_parameters.accel_tc_enable));
 
-	for (unsigned j = 0; j < 3; j++) {
+	for (unsigned j = 0; j < SENSOR_COUNT_MAX; j++) {
 		if (param_get(parameter_handles.accel_cal_handles[j].ID, &(_parameters.accel_cal_data[j].ID)) == PX4_OK) {
 			param_get(parameter_handles.accel_cal_handles[j].ref_temp, &(_parameters.accel_cal_data[j].ref_temp));
 			param_get(parameter_handles.accel_cal_handles[j].min_temp, &(_parameters.accel_cal_data[j].min_temp));
@@ -214,7 +214,7 @@ int TemperatureCompensation::parameters_update()
 	/* barometer calibration parameters */
 	param_get(parameter_handles.baro_tc_enable, &(_parameters.baro_tc_enable));
 
-	for (unsigned j = 0; j < 3; j++) {
+	for (unsigned j = 0; j < SENSOR_COUNT_MAX; j++) {
 		if (param_get(parameter_handles.baro_cal_handles[j].ID, &(_parameters.baro_cal_data[j].ID)) == PX4_OK) {
 			param_get(parameter_handles.baro_cal_handles[j].ref_temp, &(_parameters.baro_cal_data[j].ref_temp));
 			param_get(parameter_handles.baro_cal_handles[j].min_temp, &(_parameters.baro_cal_data[j].min_temp));
@@ -332,7 +332,7 @@ template<typename T>
 int TemperatureCompensation::set_sensor_id(uint32_t device_id, int topic_instance, PerSensorData &sensor_data,
 		const T *sensor_cal_data)
 {
-	for (int i = 0; i < 3; ++i) {
+	for (int i = 0; i < SENSOR_COUNT_MAX; ++i) {
 		if (device_id == sensor_cal_data[i].ID) {
 			sensor_data.device_mapping[topic_instance] = i;
 			return 0;

src/modules/sensors/temperature_compensation.h

@@ -43,9 +43,15 @@
 #include <systemlib/param/param.h>
 #include <mathlib/mathlib.h>
 
+#include "common.h"
+
+
 namespace sensors
 {
 
+static_assert(SENSOR_COUNT_MAX == 3,
+	      "SENSOR_COUNT_MAX must be 3 (if changed, add/remove TC_* params to match the count)");
+
 /**
  ** class TemperatureCompensation
  * Applies temperature compensation to sensor data. Loads the parameters from PX4 param storage.
@@ -173,21 +179,21 @@ private:
 	// create a struct containing all thermal calibration parameters
 	struct Parameters {
 		int gyro_tc_enable;
-		SensorCalData3D gyro_cal_data[3];
+		SensorCalData3D gyro_cal_data[SENSOR_COUNT_MAX];
 		int accel_tc_enable;
-		SensorCalData3D accel_cal_data[3];
+		SensorCalData3D accel_cal_data[SENSOR_COUNT_MAX];
 		int baro_tc_enable;
-		SensorCalData1D baro_cal_data[3];
+		SensorCalData1D baro_cal_data[SENSOR_COUNT_MAX];
 	};
 
 	// create a struct containing the handles required to access all calibration parameters
 	struct ParameterHandles {
 		param_t gyro_tc_enable;
-		SensorCalHandles3D gyro_cal_handles[3];
+		SensorCalHandles3D gyro_cal_handles[SENSOR_COUNT_MAX];
 		param_t accel_tc_enable;
-		SensorCalHandles3D accel_cal_handles[3];
+		SensorCalHandles3D accel_cal_handles[SENSOR_COUNT_MAX];
 		param_t baro_tc_enable;
-		SensorCalHandles1D baro_cal_handles[3];
+		SensorCalHandles1D baro_cal_handles[SENSOR_COUNT_MAX];
 	};
 
 
@@ -243,9 +249,9 @@ private:
 	struct PerSensorData {
 		PerSensorData()
 		{
-			device_mapping[0] = device_mapping[1] = device_mapping[2] = 255;
+			for (int i = 0; i < SENSOR_COUNT_MAX; ++i) { device_mapping[i] = 255; }
 		}
-		uint8_t device_mapping[3]; /// map a topic instance to the parameters index
+		uint8_t device_mapping[SENSOR_COUNT_MAX]; /// map a topic instance to the parameters index
 		int8_t last_temperature = -100;
 	};
 	PerSensorData _gyro_data;

src/modules/sensors/voted_sensors_update.h

@@ -59,12 +59,11 @@
 #include <DevMgr.hpp>
 
 #include "temperature_compensation.h"
+#include "common.h"
 
 namespace sensors
 {
 
-static const int SENSOR_COUNT_MAX = 3;
-
 /**
  ** class VotedSensorsUpdate
  *