Merge branch 'master' of github.com:PX4/Firmware into bottle_drop_friday

src/drivers/ets_airspeed/ets_airspeed.cpp

@@ -155,7 +155,6 @@ ETSAirspeed::collect()
 	}
 
 	uint16_t diff_pres_pa_raw = val[1] << 8 | val[0];
-	uint16_t diff_pres_pa;
         if (diff_pres_pa_raw == 0) {
 		// a zero value means the pressure sensor cannot give us a
 		// value. We need to return, and not report a value or the
@@ -166,28 +165,21 @@ ETSAirspeed::collect()
 		return -1;
         }
 
-	if (diff_pres_pa_raw < _diff_pres_offset + MIN_ACCURATE_DIFF_PRES_PA) {
-		diff_pres_pa = 0;
-	} else {
-		diff_pres_pa = diff_pres_pa_raw - _diff_pres_offset;
-	}
-
 	// The raw value still should be compensated for the known offset
 	diff_pres_pa_raw -= _diff_pres_offset;
 
 	// Track maximum differential pressure measured (so we can work out top speed).
-	if (diff_pres_pa > _max_differential_pressure_pa) {
-		_max_differential_pressure_pa = diff_pres_pa;
+	if (diff_pres_pa_raw > _max_differential_pressure_pa) {
+		_max_differential_pressure_pa = diff_pres_pa_raw;
 	}
 
 	differential_pressure_s report;
 	report.timestamp = hrt_absolute_time();
         report.error_count = perf_event_count(_comms_errors);
-	report.differential_pressure_pa = (float)diff_pres_pa;
 
 	// XXX we may want to smooth out the readings to remove noise.
-	report.differential_pressure_filtered_pa = (float)diff_pres_pa;
-	report.differential_pressure_raw_pa = (float)diff_pres_pa_raw;
+	report.differential_pressure_filtered_pa = diff_pres_pa_raw;
+	report.differential_pressure_raw_pa = diff_pres_pa_raw;
 	report.temperature = -1000.0f;
 	report.max_differential_pressure_pa = _max_differential_pressure_pa;
 
@@ -369,7 +361,7 @@ test()
 		err(1, "immediate read failed");
 
 	warnx("single read");
-	warnx("diff pressure: %f pa", (double)report.differential_pressure_pa);
+	warnx("diff pressure: %f pa", (double)report.differential_pressure_filtered_pa);
 
 	/* start the sensor polling at 2Hz */
 	if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2))
@@ -394,7 +386,7 @@ test()
 			err(1, "periodic read failed");
 
 		warnx("periodic read %u", i);
-		warnx("diff pressure: %f pa", (double)report.differential_pressure_pa);
+		warnx("diff pressure: %f pa", (double)report.differential_pressure_filtered_pa);
 	}
 
 	/* reset the sensor polling to its default rate */

src/drivers/meas_airspeed/meas_airspeed.cpp

@@ -228,44 +228,23 @@ MEASAirspeed::collect()
 	// the raw value still should be compensated for the known offset
 	diff_press_pa_raw -= _diff_pres_offset;
 
-	float diff_press_pa = fabsf(diff_press_pa_raw);
-	
 	/*
-	  note that we return both the absolute value with offset
-	  applied and a raw value without the offset applied. This
-	  makes it possible for higher level code to detect if the
-	  user has the tubes connected backwards, and also makes it
-	  possible to correctly use offsets calculated by a higher
-	  level airspeed driver.
-
 	  With the above calculation the MS4525 sensor will produce a
 	  positive number when the top port is used as a dynamic port
 	  and bottom port is used as the static port
-
-	  Also note that the _diff_pres_offset is applied before the
-	  fabsf() not afterwards. It needs to be done this way to
-	  prevent a bias at low speeds, but this also means that when
-	  setting a offset you must set it based on the raw value, not
-	  the offset value
 	 */
-	
+
 	struct differential_pressure_s report;
 
 	/* track maximum differential pressure measured (so we can work out top speed). */
-	if (diff_press_pa > _max_differential_pressure_pa) {
-		_max_differential_pressure_pa = diff_press_pa;
+	if (diff_press_pa_raw > _max_differential_pressure_pa) {
+		_max_differential_pressure_pa = diff_press_pa_raw;
 	}
 
 	report.timestamp = hrt_absolute_time();
 	report.error_count = perf_event_count(_comms_errors);
 	report.temperature = temperature;
-	report.differential_pressure_pa = diff_press_pa;
-	report.differential_pressure_filtered_pa =  _filter.apply(diff_press_pa);
-
-	/* the dynamics of the filter can make it overshoot into the negative range */
-	if (report.differential_pressure_filtered_pa < 0.0f) {
-		report.differential_pressure_filtered_pa = _filter.reset(diff_press_pa);
-	}
+	report.differential_pressure_filtered_pa =  _filter.apply(diff_press_pa_raw);
 
 	report.differential_pressure_raw_pa = diff_press_pa_raw;
 	report.max_differential_pressure_pa = _max_differential_pressure_pa;
@@ -345,7 +324,7 @@ MEASAirspeed::cycle()
 /**
    correct for 5V rail voltage if the system_power ORB topic is
    available
-   
+
    See http://uav.tridgell.net/MS4525/MS4525-offset.png for a graph of
    offset versus voltage for 3 sensors
  */
@@ -394,7 +373,7 @@ MEASAirspeed::voltage_correction(float &diff_press_pa, float &temperature)
 	if (voltage_diff < -1.0f) {
 		voltage_diff = -1.0f;
 	}
-	temperature -= voltage_diff * temp_slope;	
+	temperature -= voltage_diff * temp_slope;
 #endif // CONFIG_ARCH_BOARD_PX4FMU_V2
 }
 
@@ -523,7 +502,7 @@ test()
 	}
 
 	warnx("single read");
-	warnx("diff pressure: %d pa", (int)report.differential_pressure_pa);
+	warnx("diff pressure: %d pa", (int)report.differential_pressure_filtered_pa);
 
 	/* start the sensor polling at 2Hz */
 	if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) {
@@ -551,7 +530,7 @@ test()
 		}
 
 		warnx("periodic read %u", i);
-		warnx("diff pressure: %d pa", (int)report.differential_pressure_pa);
+		warnx("diff pressure: %d pa", (int)report.differential_pressure_filtered_pa);
 		warnx("temperature: %d C (0x%02x)", (int)report.temperature, (unsigned) report.temperature);
 	}