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Diffstat (limited to 'src/modules/uavcan/sensors/baro.cpp')
-rw-r--r-- | src/modules/uavcan/sensors/baro.cpp | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/src/modules/uavcan/sensors/baro.cpp b/src/modules/uavcan/sensors/baro.cpp new file mode 100644 index 000000000..80c5e3828 --- /dev/null +++ b/src/modules/uavcan/sensors/baro.cpp @@ -0,0 +1,117 @@ +/**************************************************************************** + * + * Copyright (C) 2014 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. + * + ****************************************************************************/ + +/** + * @author Pavel Kirienko <pavel.kirienko@gmail.com> + */ + +#include "baro.hpp" +#include <cmath> + +static const orb_id_t BARO_TOPICS[2] = { + ORB_ID(sensor_baro0), + ORB_ID(sensor_baro1) +}; + +const char *const UavcanBarometerBridge::NAME = "baro"; + +UavcanBarometerBridge::UavcanBarometerBridge(uavcan::INode& node) : +UavcanCDevSensorBridgeBase("uavcan_baro", "/dev/uavcan/baro", BARO_DEVICE_PATH, BARO_TOPICS), +_sub_air_data(node) +{ +} + +int UavcanBarometerBridge::init() +{ + int res = device::CDev::init(); + if (res < 0) { + return res; + } + + res = _sub_air_data.start(AirDataCbBinder(this, &UavcanBarometerBridge::air_data_sub_cb)); + if (res < 0) { + log("failed to start uavcan sub: %d", res); + return res; + } + return 0; +} + +int UavcanBarometerBridge::ioctl(struct file *filp, int cmd, unsigned long arg) +{ + switch (cmd) { + case BAROIOCSMSLPRESSURE: { + if ((arg < 80000) || (arg > 120000)) { + return -EINVAL; + } else { + log("new msl pressure %u", _msl_pressure); + _msl_pressure = arg; + return OK; + } + } + case BAROIOCGMSLPRESSURE: { + return _msl_pressure; + } + default: { + return CDev::ioctl(filp, cmd, arg); + } + } +} + +void UavcanBarometerBridge::air_data_sub_cb(const uavcan::ReceivedDataStructure<uavcan::equipment::air_data::StaticAirData> &msg) +{ + auto report = ::baro_report(); + + report.timestamp = msg.getUtcTimestamp().toUSec(); + if (report.timestamp == 0) { + report.timestamp = msg.getMonotonicTimestamp().toUSec(); + } + + report.temperature = msg.static_temperature; + report.pressure = msg.static_pressure / 100.0F; // Convert to millibar + + /* + * Altitude computation + * Refer to the MS5611 driver for details + */ + const double T1 = 15.0 + 273.15; // temperature at base height in Kelvin + const double a = -6.5 / 1000; // temperature gradient in degrees per metre + const double g = 9.80665; // gravity constant in m/s/s + const double R = 287.05; // ideal gas constant in J/kg/K + + const double p1 = _msl_pressure / 1000.0; // current pressure at MSL in kPa + const double p = double(msg.static_pressure) / 1000.0; // measured pressure in kPa + + report.altitude = (((std::pow((p / p1), (-(a * R) / g))) * T1) - T1) / a; + + publish(msg.getSrcNodeID().get(), &report); +} |