MS5525 differential pressure driver

ROMFS/px4fmu_common/init.d/rc.sensors

@@ -8,7 +8,6 @@ then
 	if ms5611 start
 	then
 	fi
-
 else
 	if ver hwcmp AEROFC_V1
 	then
@@ -142,11 +141,6 @@ then
 		if hmc5883 -C -T -S -R 8 start
 		then
 		fi
-
-		if meas_airspeed start -b 2
-		then
-		fi
-
 	else
 		# FMUv2
 		if mpu6000 start
@@ -333,7 +327,6 @@ fi
 
 if ver hwcmp PX4FMU_V4PRO
 then
-
 	# Internal SPI bus ICM-20608-G
 	if mpu6000 -R 2 -T 20608 start
 	then
@@ -358,7 +351,6 @@ then
 	if hmc5883 -C -T -X start
 	then
 	fi
-
 fi
 
 if ver hwcmp PX4FMU_V5
@@ -388,12 +380,6 @@ then
 	if hmc5883 -C -T -X start
 	then
 	fi
-
-	# Possible external airspeed sensor
-	if meas_airspeed start -b 2
-	then
-	fi
-
 fi
 
 if ver hwcmp AEROCORE2
@@ -404,13 +390,30 @@ fi
 
 if sdp3x_airspeed start
 then
-else
+fi
-	if meas_airspeed start
+
-	then
+if ms5525_airspeed start
-	else
+then
-		ets_airspeed start
+fi
-		ets_airspeed start -b 1
+
-	fi
+if ms5525_airspeed start -b 2
+then
+fi
+
+if ms4525_airspeed start
+then
+fi
+
+if ms4525_airspeed start -b 2
+then
+fi
+
+if ets_airspeed start
+then
+fi
+
+if ets_airspeed start -b 1
+then
 fi
 
 # Wait 20 ms for sensors (because we need to wait for the HRT and work queue callbacks to fire)

ROMFS/px4fmu_test/init.d/rc.sensors

@@ -73,11 +73,6 @@ then
 		if hmc5883 -C -T -S -R 8 start
 		then
 		fi
-
-		if meas_airspeed start -b 2
-		then
-		fi
-
 	else
 		# FMUv2
 		if mpu6000 start
@@ -179,16 +174,32 @@ then
 	fi
 fi
 
-if meas_airspeed start
+if sdp3x_airspeed start
+then
+fi
+
+if ms5525_airspeed start
+then
+fi
+
+if ms5525_airspeed start -b 2
+then
+fi
+
+if ms4525_airspeed start
+then
+fi
+
+if ms4525_airspeed start -b 2
+then
+fi
+
+if ets_airspeed start
+then
+fi
+
+if ets_airspeed start -b 1
 then
-else
-	if ets_airspeed start
-	then
-	else
-		if ets_airspeed start -b 1
-		then
-		fi
-	fi
 fi
 
 if sf1xx start

cmake/configs/nuttx_aerocore2_default.cmake

@@ -26,6 +26,7 @@ set(config_module_list
 	drivers/airspeed
 	drivers/ets_airspeed
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	#drivers/frsky_telemetry
 	modules/sensors
 	#drivers/pwm_input

cmake/configs/nuttx_auav-x21_default.cmake

@@ -38,6 +38,7 @@ set(config_module_list
 	drivers/airspeed
 	drivers/ets_airspeed
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/frsky_telemetry
 	modules/sensors
 	drivers/mkblctrl

cmake/configs/nuttx_mindpx-v2_default.cmake

@@ -41,6 +41,7 @@ set(config_module_list
 	drivers/airspeed
 	drivers/ets_airspeed
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/frsky_telemetry
 	modules/sensors
 	#drivers/mkblctrl

cmake/configs/nuttx_px4fmu-v1_default.cmake

@@ -36,6 +36,7 @@ set(config_module_list
 	drivers/airspeed
 	drivers/ets_airspeed
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/frsky_telemetry
 	modules/sensors
 	drivers/vmount

cmake/configs/nuttx_px4fmu-v2_default.cmake

@@ -40,6 +40,7 @@ set(config_module_list
 	drivers/sdp3x_airspeed
 	drivers/ets_airspeed
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/frsky_telemetry
 	modules/sensors
 	#drivers/mkblctrl

cmake/configs/nuttx_px4fmu-v2_test.cmake

@@ -39,6 +39,7 @@ set(config_module_list
 	drivers/airspeed
 	drivers/ets_airspeed
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/frsky_telemetry
 	modules/sensors
 	#drivers/mkblctrl

cmake/configs/nuttx_px4fmu-v3_default.cmake

@@ -33,6 +33,7 @@ set(config_module_list
 	drivers/lsm303d
 	drivers/mb12xx
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/mkblctrl
 	drivers/mpu6000
 	drivers/mpu9250

cmake/configs/nuttx_px4fmu-v4_default.cmake

@@ -38,6 +38,7 @@ set(config_module_list
 	drivers/airspeed
 	drivers/ets_airspeed
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/frsky_telemetry
 	modules/sensors
 	drivers/mkblctrl

cmake/configs/nuttx_px4fmu-v4pro_default.cmake

@@ -34,6 +34,7 @@ set(config_module_list
 	drivers/lsm303d
 	drivers/mb12xx
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/mkblctrl
 	drivers/mpu6000
 	drivers/mpu9250

cmake/configs/nuttx_px4fmu-v5_default.cmake

@@ -33,6 +33,7 @@ set(config_module_list
 	drivers/ll40ls
 	drivers/mb12xx
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/mkblctrl
 	drivers/mpu6000
 	drivers/mpu9250

cmake/configs/nuttx_px4nucleoF767ZI-v1_default.cmake

@@ -36,6 +36,7 @@ set(config_module_list
 	drivers/airspeed
 	drivers/ets_airspeed
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	drivers/frsky_telemetry
 	modules/sensors
 	drivers/mkblctrl

cmake/configs/nuttx_tap-v1_default.cmake

@@ -25,6 +25,7 @@ set(config_module_list
 	drivers/gps
 	drivers/airspeed
 	drivers/meas_airspeed
+	drivers/ms5525_airspeed
 	modules/sensors
 	drivers/vmount
 

src/drivers/airspeed/airspeed.cpp

@@ -151,7 +151,7 @@ Airspeed::init()
 		_airspeed_pub = orb_advertise(ORB_ID(differential_pressure), &arp);
 
 		if (_airspeed_pub == nullptr) {
-			warnx("uORB started?");
+			PX4_WARN("uORB started?");
 		}
 	}
 
@@ -190,7 +190,7 @@ Airspeed::ioctl(struct file *filp, int cmd, unsigned long arg)
 				_measure_ticks = 0;
 				return OK;
 
-			/* external signalling (DRDY) not supported */
+			/* external signaling (DRDY) not supported */
 			case SENSOR_POLLRATE_EXTERNAL:
 
 			/* zero would be bad */

src/drivers/airspeed/airspeed.h

@@ -81,7 +81,7 @@
 #include <uORB/topics/subsystem_info.h>
 
 /* Default I2C bus */
-#define PX4_I2C_BUS_DEFAULT		PX4_I2C_BUS_EXPANSION
+static constexpr uint8_t PX4_I2C_BUS_DEFAULT = PX4_I2C_BUS_EXPANSION;
 
 #ifndef CONFIG_SCHED_WORKQUEUE
 # error This requires CONFIG_SCHED_WORKQUEUE.
@@ -130,7 +130,7 @@ protected:
 	float			_max_differential_pressure_pa;
 	bool			_sensor_ok;
 	bool			_last_published_sensor_ok;
-	int			_measure_ticks;
+	uint32_t		_measure_ticks;
 	bool			_collect_phase;
 	float			_diff_pres_offset;
 

src/drivers/ets_airspeed/ets_airspeed.cpp

@@ -319,7 +319,8 @@ fail:
 		g_dev = nullptr;
 	}
 
-	errx(1, "no ETS airspeed sensor connected");
+	PX4_WARN("no ETS airspeed sensor connected");
+	exit(1);
 }
 
 /**

src/drivers/meas_airspeed/meas_airspeed.cpp

@@ -43,7 +43,6 @@
  * Supported sensors:
  *
  *    - MS4525DO (http://www.meas-spec.com/downloads/MS4525DO.pdf)
- *    - untested: MS5525DSO (http://www.meas-spec.com/downloads/MS5525DSO.pdf)
  *
  * Interface application notes:
  *
@@ -94,9 +93,6 @@
 /* I2C bus address is 1010001x */
 #define I2C_ADDRESS_MS4525DO	0x28	/**< 7-bit address. Depends on the order code (this is for code "I") */
 #define PATH_MS4525		"/dev/ms4525"
-/* The MS5525DSO address is 111011Cx, where C is the complementary value of the pin CSB */
-#define I2C_ADDRESS_MS5525DSO	0x77	//0x77/* 7-bit address, addr. pin pulled low */
-#define PATH_MS5525		"/dev/ms5525"
 
 /* Register address */
 #define ADDR_READ_MR			0x00	/* write to this address to start conversion */
@@ -440,22 +436,6 @@ start(int i2c_bus)
 		goto fail;
 	}
 
-	/* try the MS5525DSO next if init fails */
-	if (OK != g_dev->Airspeed::init()) {
-		delete g_dev;
-		g_dev = new MEASAirspeed(i2c_bus, I2C_ADDRESS_MS5525DSO, PATH_MS5525);
-
-		/* check if the MS5525DSO was instantiated */
-		if (g_dev == nullptr) {
-			goto fail;
-		}
-
-		/* both versions failed if the init for the MS5525DSO fails, give up */
-		if (OK != g_dev->Airspeed::init()) {
-			goto fail;
-		}
-	}
-
 	/* set the poll rate to default, starts automatic data collection */
 	fd = open(PATH_MS4525, O_RDONLY);
 
@@ -476,7 +456,8 @@ fail:
 		g_dev = nullptr;
 	}
 
-	errx(1, "no MS4525 airspeed sensor connected");
+	PX4_WARN("no MS4525 airspeed sensor connected");
+	exit(1);
 }
 
 /**

src/drivers/ms5525_airspeed/CMakeLists.txt

@@ -0,0 +1,44 @@
+############################################################################
+#
+#   Copyright (c) 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.
+#
+############################################################################
+px4_add_module(
+	MODULE drivers__ms5525_airspeed
+	MAIN ms5525_airspeed
+	STACK_MAIN 1200
+	COMPILE_FLAGS
+	SRCS
+		MS5525.cpp
+		MS5525_main.cpp
+	DEPENDS
+		platforms__common
+	)
+# vim: set noet ft=cmake fenc=utf-8 ff=unix :

src/drivers/ms5525_airspeed/MS5525.cpp

@@ -0,0 +1,331 @@
+/****************************************************************************
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+#include "MS5525.hpp"
+
+int
+MS5525::measure()
+{
+	int ret = PX4_ERROR;
+
+	if (_inited) {
+		// send the command to begin a conversion.
+		uint8_t cmd = _current_cmd;
+		ret = transfer(&cmd, 1, nullptr, 0);
+
+		if (ret != PX4_OK) {
+			perf_count(_comms_errors);
+		}
+
+	} else {
+		_inited = init_ms5525();
+
+		if (_inited) {
+			ret = PX4_OK;
+		}
+	}
+
+	return ret;
+}
+
+bool
+MS5525::init_ms5525()
+{
+	// Step 1 - reset
+	uint8_t cmd = CMD_RESET;
+	int ret = transfer(&cmd, 1, nullptr, 0);
+
+	if (ret != PX4_OK) {
+		perf_count(_comms_errors);
+		return false;
+	}
+
+	usleep(3000);
+
+	// Step 2 - read calibration coefficients from prom
+
+	// prom layout
+	// 0 factory data and the setup
+	// 1-6 calibration coefficients
+	// 7 serial code and CRC
+	uint16_t prom[8];
+
+	for (uint8_t i = 0; i < 8; i++) {
+		cmd = CMD_PROM_START + i * 2;
+
+		// request PROM value
+		ret = transfer(&cmd, 1, nullptr, 0);
+
+		if (ret != PX4_OK) {
+			perf_count(_comms_errors);
+			return false;
+		}
+
+		// read 2 byte value
+		uint8_t val[2];
+		ret = transfer(nullptr, 0, &val[0], 2);
+
+		if (ret == PX4_OK) {
+			prom[i] = (val[0] << 8) | val[1];
+
+		} else {
+			perf_count(_comms_errors);
+			return false;
+		}
+	}
+
+	// Step 3 - check CRC
+	const uint8_t crc = prom_crc4(prom);
+	const uint8_t onboard_crc = prom[7] & 0xF;
+
+	if (crc == onboard_crc) {
+		// store valid calibration coefficients
+		C1 = prom[1];
+		C2 = prom[2];
+		C3 = prom[3];
+		C4 = prom[4];
+		C5 = prom[5];
+		C6 = prom[6];
+
+		Tref = C5 * (1UL << Q5);
+
+		return true;
+
+	} else {
+		PX4_ERR("CRC mismatch");
+		return false;
+	}
+}
+
+uint8_t
+MS5525::prom_crc4(uint16_t n_prom[]) const
+{
+	// see Measurement Specialties AN520
+
+	// crc remainder
+	unsigned int n_rem = 0x00;
+
+	// original value of the crc
+	unsigned int crc_read = n_prom[7]; // save read CRC
+	n_prom[7] = (0xFF00 & (n_prom[7])); // CRC byte is replaced by 0
+
+	// operation is performed on bytes
+	for (int cnt = 0; cnt < 16; cnt++) {
+		// choose LSB or MSB
+		if (cnt % 2 == 1) {
+			n_rem ^= (unsigned short)((n_prom[cnt >> 1]) & 0x00FF);
+
+		} else {
+			n_rem ^= (unsigned short)(n_prom[cnt >> 1] >> 8);
+		}
+
+		for (uint8_t n_bit = 8; n_bit > 0; n_bit--) {
+			if (n_rem & (0x8000)) {
+				n_rem = (n_rem << 1) ^ 0x3000;
+
+			} else {
+				n_rem = (n_rem << 1);
+			}
+		}
+	}
+
+	n_rem = (0x000F & (n_rem >> 12)); // final 4-bit reminder is CRC code
+	n_prom[7] = crc_read; // restore the crc_read to its original place
+
+	return (n_rem ^ 0x00);
+}
+
+int
+MS5525::collect()
+{
+	perf_begin(_sample_perf);
+
+	// read ADC
+	uint8_t cmd = CMD_ADC_READ;
+	int ret = transfer(&cmd, 1, nullptr, 0);
+
+	if (ret != PX4_OK) {
+		perf_count(_comms_errors);
+		return ret;
+	}
+
+	// read 24 bits from the sensor
+	uint8_t val[3];
+	ret = transfer(nullptr, 0, &val[0], 3);
+
+	if (ret != PX4_OK) {
+		perf_count(_comms_errors);
+		return ret;
+	}
+
+	uint32_t adc = (val[0] << 16) | (val[1] << 8) | val[2];
+
+	// If the conversion is not executed before the ADC read command, or the ADC read command is repeated, it will give 0 as the output
+	// result. If the ADC read command is sent during conversion the result will be 0, the conversion will not stop and
+	// the final result will be wrong. Conversion sequence sent during the already started conversion process will yield
+	// incorrect result as well.
+	if (adc == 0) {
+		perf_count(_comms_errors);
+		return EAGAIN;
+	}
+
+	if (_current_cmd == CMD_CONVERT_PRES) {
+		D1 = adc;
+		_pressure_count++;
+
+		if (_pressure_count > 9) {
+			_pressure_count = 0;
+			_current_cmd = CMD_CONVERT_TEMP;
+		}
+
+	} else if (_current_cmd == CMD_CONVERT_TEMP) {
+		D2 = adc;
+		_current_cmd = CMD_CONVERT_PRES;
+
+		// only calculate and publish after new pressure readings
+		return PX4_OK;
+	}
+
+	// not ready yet
+	if (D1 == 0 || D2 == 0) {
+		return EAGAIN;
+	}
+
+	// Difference between actual and reference temperature
+	//  dT = D2 - Tref
+	const int32_t dT = D2 - Tref;
+
+	// Measured temperature
+	//  TEMP = 20°C + dT * TEMPSENS
+	const int32_t TEMP = 2000 + (dT * C6) / (1L << Q6);
+
+	// Offset at actual temperature
+	//  OFF = OFF_T1 + TCO * dT
+	const int64_t OFF = C2 * (1L << Q2) + (C4 * dT) / (1L << Q4);
+
+	// Sensitivity at actual temperature
+	//  SENS = SENS_T1 + TCS * dT
+	const int64_t SENS = C1 * (1L << Q1) + (C3 * dT) / (1L << Q3);
+
+	// Temperature Compensated Pressure (example 24996 = 2.4996 psi)
+	//  P = D1 * SENS - OFF
+	const int64_t P = (((int64_t)D1 * SENS) / (1L << 21) - OFF) / (1L << 15);
+
+	const float diff_press_PSI = (float)P * 0.0001f;
+
+	// 1 PSI = 6894.76 Pascals
+	const float PSI_to_Pa = 6894.757f;
+	float diff_press_pa_raw = diff_press_PSI * PSI_to_Pa;
+
+	const float temperature_c = (float)TEMP * 0.01f;
+
+	// the raw value still should be compensated for the known offset
+	diff_press_pa_raw -= _diff_pres_offset;
+
+	/* track maximum differential pressure measured (so we can work out top speed). */
+	if (diff_press_pa_raw > _max_differential_pressure_pa) {
+		_max_differential_pressure_pa = diff_press_pa_raw;
+	}
+
+	differential_pressure_s diff_pressure = {
+		.timestamp = hrt_absolute_time(),
+		.error_count = perf_event_count(_comms_errors),
+		.differential_pressure_raw_pa = diff_press_pa_raw,
+		.differential_pressure_filtered_pa =  _filter.apply(diff_press_pa_raw),
+		.max_differential_pressure_pa = _max_differential_pressure_pa,
+		.temperature = temperature_c
+	};
+
+	if (_airspeed_pub != nullptr && !(_pub_blocked)) {
+		/* publish it */
+		orb_publish(ORB_ID(differential_pressure), _airspeed_pub, &diff_pressure);
+	}
+
+	new_report(diff_pressure);
+
+	/* notify anyone waiting for data */
+	poll_notify(POLLIN);
+
+	ret = OK;
+
+	perf_end(_sample_perf);
+
+	return ret;
+}
+
+void
+MS5525::cycle()
+{
+	int ret = PX4_ERROR;
+
+	// collection phase
+	if (_collect_phase) {
+		// perform collection
+		ret = collect();
+
+		if (OK != ret) {
+			/* restart the measurement state machine */
+			start();
+			_sensor_ok = false;
+			return;
+		}
+
+		// next phase is measurement
+		_collect_phase = false;
+
+		// is there a collect->measure gap?
+		if (_measure_ticks > USEC2TICK(CONVERSION_INTERVAL)) {
+
+			// schedule a fresh cycle call when we are ready to measure again
+			work_queue(HPWORK, &_work, (worker_t)&Airspeed::cycle_trampoline, this,
+				   _measure_ticks - USEC2TICK(CONVERSION_INTERVAL));
+
+			return;
+		}
+	}
+
+	/* measurement phase */
+	ret = measure();
+
+	if (OK != ret) {
+		DEVICE_DEBUG("measure error");
+	}
+
+	_sensor_ok = (ret == OK);
+
+	// next phase is collection
+	_collect_phase = true;
+
+	// schedule a fresh cycle call when the measurement is done
+	work_queue(HPWORK, &_work, (worker_t)&Airspeed::cycle_trampoline, this, USEC2TICK(CONVERSION_INTERVAL));
+}

src/drivers/ms5525_airspeed/MS5525.hpp

@@ -0,0 +1,138 @@
+/****************************************************************************
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+#ifndef DRIVERS_MS5525_AIRSPEED_HPP_
+#define DRIVERS_MS5525_AIRSPEED_HPP_
+
+#include <drivers/airspeed/airspeed.h>
+#include <drivers/device/i2c.h>
+#include <drivers/drv_airspeed.h>
+#include <math.h>
+#include <mathlib/math/filter/LowPassFilter2p.hpp>
+#include <px4_config.h>
+#include <sys/types.h>
+#include <systemlib/airspeed.h>
+#include <systemlib/perf_counter.h>
+#include <uORB/topics/differential_pressure.h>
+#include <uORB/uORB.h>
+
+/* The MS5525DSO address is 111011Cx, where C is the complementary value of the pin CSB */
+static constexpr uint8_t I2C_ADDRESS_1_MS5525DSO = 0x76;
+static constexpr uint8_t I2C_ADDRESS_2_MS5525DSO = 0x77;
+
+static constexpr const char PATH_MS5525[] = "/dev/ms5525";
+
+/* Measurement rate is 100Hz */
+static constexpr unsigned MEAS_RATE = 100;
+static constexpr float MEAS_DRIVER_FILTER_FREQ = 1.2f;
+static constexpr uint64_t CONVERSION_INTERVAL = (1000000 / MEAS_RATE); /* microseconds */
+
+class MS5525 : public Airspeed
+{
+public:
+	MS5525(uint8_t bus, uint8_t address = I2C_ADDRESS_1_MS5525DSO, const char *path = PATH_MS5525) :
+		Airspeed(bus, address, CONVERSION_INTERVAL, path)
+	{
+	}
+
+	~MS5525() override = default;
+
+private:
+
+	/**
+	* Perform a poll cycle; collect from the previous measurement
+	* and start a new one.
+	*/
+	void cycle() override;
+
+	int measure() override;
+	int collect() override;
+
+	math::LowPassFilter2p _filter{MEAS_RATE, MEAS_DRIVER_FILTER_FREQ};
+
+	static constexpr uint8_t CMD_RESET = 0x1E; // ADC reset command
+	static constexpr uint8_t CMD_ADC_READ = 0x00; // ADC read command
+
+	static constexpr uint8_t CMD_PROM_START = 0xA0; // Prom read command (first)
+
+	// D1 - pressure convert commands
+	// Convert D1 (OSR=256)  0x40
+	// Convert D1 (OSR=512)  0x42
+	// Convert D1 (OSR=1024) 0x44
+	// Convert D1 (OSR=2048) 0x46
+	// Convert D1 (OSR=4096) 0x48
+	static constexpr uint8_t CMD_CONVERT_PRES = 0x44;
+
+	// D2 - temperature convert commands
+	// Convert D2 (OSR=256)  0x50
+	// Convert D2 (OSR=512)  0x52
+	// Convert D2 (OSR=1024) 0x54
+	// Convert D2 (OSR=2048) 0x56
+	// Convert D2 (OSR=4096) 0x58
+	static constexpr uint8_t CMD_CONVERT_TEMP = 0x54;
+
+	uint8_t _current_cmd{CMD_CONVERT_PRES};
+
+	unsigned _pressure_count{0};
+
+	// Qx Coefficients Matrix by Pressure Range
+	//  5525DSO-pp001DS (Pmin = -1, Pmax = 1)
+	static constexpr uint8_t Q1 = 15;
+	static constexpr uint8_t Q2 = 17;
+	static constexpr uint8_t Q3 = 7;
+	static constexpr uint8_t Q4 = 5;
+	static constexpr uint8_t Q5 = 7;
+	static constexpr uint8_t Q6 = 21;
+
+	// calibration coefficients from prom
+	uint16_t C1{0};
+	uint16_t C2{0};
+	uint16_t C3{0};
+	uint16_t C4{0};
+	uint16_t C5{0};
+	uint16_t C6{0};
+
+	uint32_t Tref{0};
+
+	// last readings for D1 (uncompensated pressure) and D2 (uncompensated temperature)
+	uint32_t D1{0};
+	uint32_t D2{0};
+
+	bool init_ms5525();
+	bool _inited{false};
+
+	uint8_t prom_crc4(uint16_t n_prom[]) const;
+
+};
+
+#endif /* DRIVERS_MS5525_AIRSPEED_HPP_ */

src/drivers/ms5525_airspeed/MS5525_main.cpp

@@ -0,0 +1,270 @@
+/****************************************************************************
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+#include "MS5525.hpp"
+
+// Driver 'main' command.
+extern "C" __EXPORT int ms5525_airspeed_main(int argc, char *argv[]);
+
+// Local functions in support of the shell command.
+namespace ms5525_airspeed
+{
+MS5525 *g_dev = nullptr;
+
+void start(uint8_t i2c_bus);
+void stop();
+void test();
+void reset();
+
+// Start the driver.
+// This function call only returns once the driver is up and running
+// or failed to detect the sensor.
+void
+start(uint8_t i2c_bus)
+{
+	int fd = -1;
+
+	if (g_dev != nullptr) {
+		PX4_ERR("already started");
+		exit(1);
+	}
+
+	g_dev = new MS5525(i2c_bus, I2C_ADDRESS_1_MS5525DSO, PATH_MS5525);
+
+	/* check if the MS4525DO was instantiated */
+	if (g_dev == nullptr) {
+		goto fail;
+	}
+
+	/* try the next MS5525DSO if init fails */
+	if (OK != g_dev->Airspeed::init()) {
+		delete g_dev;
+
+		PX4_WARN("trying MS5525 address 2");
+
+		g_dev = new MS5525(i2c_bus, I2C_ADDRESS_2_MS5525DSO, PATH_MS5525);
+
+		/* check if the MS5525DSO was instantiated */
+		if (g_dev == nullptr) {
+			PX4_WARN("MS5525 was not instantiated");
+			goto fail;
+		}
+
+		/* both versions failed if the init for the MS5525DSO fails, give up */
+		if (OK != g_dev->Airspeed::init()) {
+			PX4_WARN("MS5525 init fail");
+			goto fail;
+		}
+	}
+
+	/* set the poll rate to default, starts automatic data collection */
+	fd = open(PATH_MS5525, O_RDONLY);
+
+	if (fd < 0) {
+		goto fail;
+	}
+
+	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0) {
+		goto fail;
+	}
+
+	exit(0);
+
+fail:
+
+	if (g_dev != nullptr) {
+		delete g_dev;
+		g_dev = nullptr;
+	}
+
+	PX4_WARN("no MS5525 airspeed sensor connected");
+	exit(1);
+}
+
+// stop the driver
+void stop()
+{
+	if (g_dev != nullptr) {
+		delete g_dev;
+		g_dev = nullptr;
+
+	} else {
+		PX4_ERR("driver not running");
+		exit(1);
+	}
+
+	exit(0);
+}
+
+// perform some basic functional tests on the driver;
+// make sure we can collect data from the sensor in polled
+// and automatic modes.
+void test()
+{
+	int fd = open(PATH_MS5525, O_RDONLY);
+
+	if (fd < 0) {
+		PX4_WARN("%s open failed (try 'ms5525_airspeed start' if the driver is not running", PATH_MS5525);
+		exit(1);
+	}
+
+	// do a simple demand read
+	differential_pressure_s report;
+	ssize_t sz = read(fd, &report, sizeof(report));
+
+	if (sz != sizeof(report)) {
+		PX4_WARN("immediate read failed");
+		exit(1);
+	}
+
+	PX4_WARN("single read");
+	PX4_WARN("diff pressure: %d pa", (int)report.differential_pressure_filtered_pa);
+
+	/* start the sensor polling at 2Hz */
+	if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) {
+		PX4_WARN("failed to set 2Hz poll rate");
+		exit(1);
+	}
+
+	/* read the sensor 5x and report each value */
+	for (unsigned i = 0; i < 5; i++) {
+		struct pollfd fds;
+
+		/* wait for data to be ready */
+		fds.fd = fd;
+		fds.events = POLLIN;
+		int ret = poll(&fds, 1, 2000);
+
+		if (ret != 1) {
+			PX4_ERR("timed out");
+		}
+
+		/* now go get it */
+		sz = read(fd, &report, sizeof(report));
+
+		if (sz != sizeof(report)) {
+			PX4_ERR("periodic read failed");
+		}
+
+		PX4_WARN("periodic read %u", i);
+		PX4_WARN("diff pressure: %d pa", (int)report.differential_pressure_filtered_pa);
+		PX4_WARN("temperature: %d C (0x%02x)", (int)report.temperature, (unsigned) report.temperature);
+	}
+
+	/* reset the sensor polling to its default rate */
+	if (PX4_OK != ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT)) {
+		PX4_WARN("failed to set default rate");
+		exit(1);
+	}
+}
+
+// reset the driver
+void reset()
+{
+	int fd = open(PATH_MS5525, O_RDONLY);
+
+	if (fd < 0) {
+		PX4_ERR("failed ");
+		exit(1);
+	}
+
+	if (ioctl(fd, SENSORIOCRESET, 0) < 0) {
+		PX4_ERR("driver reset failed");
+		exit(1);
+	}
+
+	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0) {
+		PX4_ERR("driver poll restart failed");
+		exit(1);
+	}
+
+	exit(0);
+}
+
+} // namespace ms5525_airspeed
+
+
+static void
+ms5525_airspeed_usage()
+{
+	PX4_WARN("usage: ms5525_airspeed command [options]");
+	PX4_WARN("options:");
+	PX4_WARN("\t-b --bus i2cbus (%d)", PX4_I2C_BUS_DEFAULT);
+	PX4_WARN("command:");
+	PX4_WARN("\tstart|stop|reset|test");
+}
+
+int
+ms5525_airspeed_main(int argc, char *argv[])
+{
+	uint8_t i2c_bus = PX4_I2C_BUS_DEFAULT;
+
+	for (int i = 1; i < argc; i++) {
+		if (strcmp(argv[i], "-b") == 0 || strcmp(argv[i], "--bus") == 0) {
+			if (argc > i + 1) {
+				i2c_bus = atoi(argv[i + 1]);
+			}
+		}
+	}
+
+	/*
+	 * Start/load the driver.
+	 */
+	if (!strcmp(argv[1], "start")) {
+		ms5525_airspeed::start(i2c_bus);
+	}
+
+	/*
+	 * Stop the driver
+	 */
+	if (!strcmp(argv[1], "stop")) {
+		ms5525_airspeed::stop();
+	}
+
+	/*
+	 * Test the driver/device.
+	 */
+	if (!strcmp(argv[1], "test")) {
+		ms5525_airspeed::test();
+	}
+
+	/*
+	 * Reset the driver.
+	 */
+	if (!strcmp(argv[1], "reset")) {
+		ms5525_airspeed::reset();
+	}
+
+	ms5525_airspeed_usage();
+	exit(0);
+}

src/modules/commander/airspeed_calibration.cpp

@@ -230,7 +230,6 @@ int do_airspeed_calibration(orb_advert_t *mavlink_log_pub)
 				calibration_log_info(mavlink_log_pub, "[cal] Swap static and dynamic ports!");
 
 				/* the user setup is wrong, wipe the calibration to force a proper re-calibration */
-
 				diff_pres_offset = 0.0f;
 				if (param_set(param_find("SENS_DPRES_OFF"), &(diff_pres_offset))) {
 					calibration_log_critical(mavlink_log_pub, CAL_ERROR_SET_PARAMS_MSG, 1);