Simplified i2c handling for flow.

src/drivers/px4flow/i2c_frame.h

@@ -0,0 +1,82 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013-2015 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file i2c_frame.h
+ * Definition of i2c frames.
+ * @author Thomas Boehm <thomas.boehm@fortiss.org>
+ * @author James Goppert <james.goppert@gmail.com>
+ */
+
+#ifndef I2C_FRAME_H_
+#define I2C_FRAME_H_
+#include <inttypes.h>
+
+
+typedef  struct i2c_frame
+{
+    uint16_t frame_count;
+    int16_t pixel_flow_x_sum;
+    int16_t pixel_flow_y_sum;
+    int16_t flow_comp_m_x;
+    int16_t flow_comp_m_y;
+    int16_t qual;
+    int16_t gyro_x_rate;
+    int16_t gyro_y_rate;
+    int16_t gyro_z_rate;
+    uint8_t gyro_range;
+    uint8_t sonar_timestamp;
+    int16_t ground_distance;
+} i2c_frame;
+
+#define I2C_FRAME_SIZE (sizeof(i2c_frame))
+
+
+typedef struct i2c_integral_frame
+{
+    uint16_t frame_count_since_last_readout;
+    int16_t pixel_flow_x_integral;
+    int16_t pixel_flow_y_integral;
+    int16_t gyro_x_rate_integral;
+    int16_t gyro_y_rate_integral;
+    int16_t gyro_z_rate_integral;
+    uint32_t integration_timespan;
+    uint32_t sonar_timestamp;
+    uint16_t ground_distance;
+    int16_t gyro_temperature;
+    uint8_t qual;
+} i2c_integral_frame;
+
+#define I2C_INTEGRAL_FRAME_SIZE (sizeof(i2c_integral_frame))
+
+#endif /* I2C_FRAME_H_ */

src/drivers/px4flow/px4flow.cpp

@@ -93,38 +93,11 @@ static const int ERROR = -1;
 # error This requires CONFIG_SCHED_WORKQUEUE.
 #endif
 
-struct i2c_frame {
-	uint16_t frame_count;
-	int16_t pixel_flow_x_sum;
-	int16_t pixel_flow_y_sum;
-	int16_t flow_comp_m_x;
-	int16_t flow_comp_m_y;
-	int16_t qual;
-	int16_t gyro_x_rate;
-	int16_t gyro_y_rate;
-	int16_t gyro_z_rate;
-	uint8_t gyro_range;
-	uint8_t sonar_timestamp;
-	int16_t ground_distance;
-};
-struct i2c_frame f;
+#include "i2c_frame.h"
 
-struct i2c_integral_frame {
-	uint16_t frame_count_since_last_readout;
-	int16_t pixel_flow_x_integral;
-	int16_t pixel_flow_y_integral;
-	int16_t gyro_x_rate_integral;
-	int16_t gyro_y_rate_integral;
-	int16_t gyro_z_rate_integral;
-	uint32_t integration_timespan;
-	uint32_t time_since_last_sonar_update;
-	uint16_t ground_distance;
-	int16_t gyro_temperature;
-	uint8_t qual;
-} __attribute__((packed));
+struct i2c_frame f;
 struct i2c_integral_frame f_integral;
 
-
 class PX4FLOW: public device::I2C
 {
 public:
@@ -150,8 +123,7 @@ private:
 	RingBuffer			*_reports;
 	bool				_sensor_ok;
 	int					_measure_ticks;
-	bool				_collect_phase;
-
+	bool				_collect_phase; 
 	orb_advert_t		_px4flow_topic;
 
 	perf_counter_t		_sample_perf;
@@ -261,10 +233,10 @@ out:
 int
 PX4FLOW::probe()
 {
-	uint8_t val[22];
+	uint8_t val[I2C_FRAME_SIZE];
 
 	// to be sure this is not a ll40ls Lidar (which can also be on
-	// 0x42) we check if a 22 byte transfer works from address
+	// 0x42) we check if a I2C_FRAME_SIZE byte transfer works from address
 	// 0. The ll40ls gives an error for that, whereas the flow
 	// happily returns some data
 	if (transfer(nullptr, 0, &val[0], 22) != OK) {
@@ -469,16 +441,16 @@ PX4FLOW::collect()
 	int ret = -EIO;
 
 	/* read from the sensor */
-	uint8_t val[47] = { 0 };
+	uint8_t val[I2C_FRAME_SIZE + I2C_INTEGRAL_FRAME_SIZE] = { 0 };
 
 	perf_begin(_sample_perf);
 
 	if (PX4FLOW_REG == 0x00) {
-		ret = transfer(nullptr, 0, &val[0], 47); // read 47 bytes (22+25 : frame1 + frame2)
+		ret = transfer(nullptr, 0, &val[0], I2C_FRAME_SIZE + I2C_INTEGRAL_FRAME_SIZE);
 	}
 
 	if (PX4FLOW_REG == 0x16) {
-		ret = transfer(nullptr, 0, &val[0], 25); // read 25 bytes (only frame2)
+		ret = transfer(nullptr, 0, &val[0], I2C_INTEGRAL_FRAME_SIZE);
 	}
 
 	if (ret < 0) {
@@ -489,46 +461,12 @@ PX4FLOW::collect()
 	}
 
 	if (PX4FLOW_REG == 0) {
-		f.frame_count = val[1] << 8 | val[0];
-		f.pixel_flow_x_sum = val[3] << 8 | val[2];
-		f.pixel_flow_y_sum = val[5] << 8 | val[4];
-		f.flow_comp_m_x = val[7] << 8 | val[6];
-		f.flow_comp_m_y = val[9] << 8 | val[8];
-		f.qual = val[11] << 8 | val[10];
-		f.gyro_x_rate = val[13] << 8 | val[12];
-		f.gyro_y_rate = val[15] << 8 | val[14];
-		f.gyro_z_rate = val[17] << 8 | val[16];
-		f.gyro_range = val[18];
-		f.sonar_timestamp = val[19];
-		f.ground_distance = val[21] << 8 | val[20];
-
-		f_integral.frame_count_since_last_readout = val[23] << 8 | val[22];
-		f_integral.pixel_flow_x_integral = val[25] << 8 | val[24];
-		f_integral.pixel_flow_y_integral = val[27] << 8 | val[26];
-		f_integral.gyro_x_rate_integral = val[29] << 8 | val[28];
-		f_integral.gyro_y_rate_integral = val[31] << 8 | val[30];
-		f_integral.gyro_z_rate_integral = val[33] << 8 | val[32];
-		f_integral.integration_timespan = val[37] << 24 | val[36] << 16
-						  | val[35] << 8 | val[34];
-		f_integral.time_since_last_sonar_update = val[41] << 24 | val[40] << 16
-				| val[39] << 8 | val[38];
-		f_integral.ground_distance = val[43] << 8 | val[42];
-		f_integral.gyro_temperature = val[45] << 8 | val[44];
-		f_integral.qual = val[46];
+		memcpy(&f, val, I2C_FRAME_SIZE);
+		memcpy(&f_integral, &(val[I2C_FRAME_SIZE]), I2C_INTEGRAL_FRAME_SIZE);
 	}
 
 	if (PX4FLOW_REG == 0x16) {
-		f_integral.frame_count_since_last_readout = val[1] << 8 | val[0];
-		f_integral.pixel_flow_x_integral = val[3] << 8 | val[2];
-		f_integral.pixel_flow_y_integral = val[5] << 8 | val[4];
-		f_integral.gyro_x_rate_integral = val[7] << 8 | val[6];
-		f_integral.gyro_y_rate_integral = val[9] << 8 | val[8];
-		f_integral.gyro_z_rate_integral = val[11] << 8 | val[10];
-		f_integral.integration_timespan = val[15] << 24 | val[14] << 16 | val[13] << 8 | val[12];
-		f_integral.time_since_last_sonar_update = val[19] << 24 | val[18] << 16 | val[17] << 8 | val[16];
-		f_integral.ground_distance = val[21] << 8 | val[20];
-		f_integral.gyro_temperature = val[23] << 8 | val[22];
-		f_integral.qual = val[24];
+		memcpy(&f_integral, val, I2C_INTEGRAL_FRAME_SIZE);
 	}
 
 
@@ -544,7 +482,7 @@ PX4FLOW::collect()
 	report.gyro_y_rate_integral = static_cast<float>(f_integral.gyro_y_rate_integral) / 10000.0f; //convert to radians
 	report.gyro_z_rate_integral = static_cast<float>(f_integral.gyro_z_rate_integral) / 10000.0f; //convert to radians
 	report.integration_timespan = f_integral.integration_timespan; //microseconds
-	report.time_since_last_sonar_update = f_integral.time_since_last_sonar_update;//microseconds
+	report.time_since_last_sonar_update = f_integral.sonar_timestamp;//microseconds
 	report.gyro_temperature = f_integral.gyro_temperature;//Temperature * 100 in centi-degrees Celsius
 
 	report.sensor_id = 0;
@@ -828,7 +766,7 @@ test()
 		warnx("ground_distance: %0.2f m",
 		      (double) f_integral.ground_distance / 1000);
 		warnx("time since last sonar update [us]: %i",
-		      f_integral.time_since_last_sonar_update);
+		      f_integral.sonar_timestamp);
 		warnx("quality integration average : %i", f_integral.qual);
 		warnx("quality : %i", f.qual);