/**************************************************************************** * * Copyright (c) 2012-2019 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 ms5611.cpp * Driver for the MS5611 and MS5607 barometric pressure sensor connected via I2C or SPI. */ #include "MS5611.hpp" #include "ms5611.h" #include MS5611::MS5611(device::Device *interface, ms5611::prom_u &prom_buf, enum MS56XX_DEVICE_TYPES device_type, I2CSPIBusOption bus_option, int bus) : I2CSPIDriver(MODULE_NAME, px4::device_bus_to_wq(interface->get_device_id()), bus_option, bus, 0, device_type), _px4_barometer(interface->get_device_id()), _interface(interface), _prom(prom_buf.s), _device_type(device_type), _sample_perf(perf_alloc(PC_ELAPSED, MODULE_NAME": read")), _measure_perf(perf_alloc(PC_ELAPSED, MODULE_NAME": measure")), _comms_errors(perf_alloc(PC_COUNT, MODULE_NAME": com_err")) { } MS5611::~MS5611() { // free perf counters perf_free(_sample_perf); perf_free(_measure_perf); perf_free(_comms_errors); delete _interface; } int MS5611::init() { int ret; /* do a first measurement cycle to populate reports with valid data */ _measure_phase = 0; while (true) { /* do temperature first */ if (OK != measure()) { ret = -EIO; break; } px4_usleep(MS5611_CONVERSION_INTERVAL); if (OK != collect()) { ret = -EIO; break; } /* now do a pressure measurement */ if (OK != measure()) { ret = -EIO; break; } px4_usleep(MS5611_CONVERSION_INTERVAL); if (OK != collect()) { ret = -EIO; break; } /* state machine will have generated a report, copy it out */ const sensor_baro_s &brp = _px4_barometer.get(); if (_device_type == MS5607_DEVICE) { if (brp.pressure < 520.0f) { /* This is likely not this device, abort */ ret = -EINVAL; break; } } switch (_device_type) { default: /* fall through */ case MS5611_DEVICE: _interface->set_device_type(DRV_BARO_DEVTYPE_MS5611); _px4_barometer.set_device_type(DRV_BARO_DEVTYPE_MS5611); break; case MS5607_DEVICE: _interface->set_device_type(DRV_BARO_DEVTYPE_MS5607); _px4_barometer.set_device_type(DRV_BARO_DEVTYPE_MS5607); break; } ret = OK; break; } if (ret == 0) { start(); } return ret; } void MS5611::start() { /* reset the report ring and state machine */ _collect_phase = false; _measure_phase = 0; /* schedule a cycle to start things */ ScheduleDelayed(MS5611_CONVERSION_INTERVAL); } void MS5611::RunImpl() { int ret; unsigned dummy; /* collection phase? */ if (_collect_phase) { /* perform collection */ ret = collect(); if (ret != OK) { if (ret == -6) { /* * The ms5611 seems to regularly fail to respond to * its address; this happens often enough that we'd rather not * spam the console with a message for this. */ } else { //DEVICE_LOG("collection error %d", ret); } /* issue a reset command to the sensor */ _interface->ioctl(IOCTL_RESET, dummy); /* reset the collection state machine and try again - we need * to wait 2.8 ms after issuing the sensor reset command * according to the MS5611 datasheet */ ScheduleDelayed(2800); return; } /* next phase is measurement */ _collect_phase = false; } /* measurement phase */ ret = measure(); if (ret != OK) { /* issue a reset command to the sensor */ _interface->ioctl(IOCTL_RESET, dummy); /* reset the collection state machine and try again */ start(); return; } /* next phase is collection */ _collect_phase = true; /* schedule a fresh cycle call when the measurement is done */ ScheduleDelayed(MS5611_CONVERSION_INTERVAL); } int MS5611::measure() { perf_begin(_measure_perf); /* * In phase zero, request temperature; in other phases, request pressure. */ unsigned addr = (_measure_phase == 0) ? ADDR_CMD_CONVERT_D2 : ADDR_CMD_CONVERT_D1; /* * Send the command to begin measuring. */ int ret = _interface->ioctl(IOCTL_MEASURE, addr); if (OK != ret) { perf_count(_comms_errors); } _px4_barometer.set_error_count(perf_event_count(_comms_errors)); perf_end(_measure_perf); return ret; } int MS5611::collect() { uint32_t raw; perf_begin(_sample_perf); /* read the most recent measurement - read offset/size are hardcoded in the interface */ const hrt_abstime timestamp_sample = hrt_absolute_time(); int ret = _interface->read(0, (void *)&raw, 0); if (ret < 0) { perf_count(_comms_errors); perf_end(_sample_perf); return ret; } /* handle a measurement */ if (_measure_phase == 0) { /* temperature offset (in ADC units) */ int32_t dT = (int32_t)raw - ((int32_t)_prom.c5_reference_temp << 8); /* absolute temperature in centidegrees - note intermediate value is outside 32-bit range */ int32_t TEMP = 2000 + (int32_t)(((int64_t)dT * _prom.c6_temp_coeff_temp) >> 23); /* base sensor scale/offset values */ if (_device_type == MS5611_DEVICE) { /* Perform MS5611 Caculation */ _OFF = ((int64_t)_prom.c2_pressure_offset << 16) + (((int64_t)_prom.c4_temp_coeff_pres_offset * dT) >> 7); _SENS = ((int64_t)_prom.c1_pressure_sens << 15) + (((int64_t)_prom.c3_temp_coeff_pres_sens * dT) >> 8); /* MS5611 temperature compensation */ if (TEMP < 2000) { int32_t T2 = POW2(dT) >> 31; int64_t f = POW2((int64_t)TEMP - 2000); int64_t OFF2 = 5 * f >> 1; int64_t SENS2 = 5 * f >> 2; if (TEMP < -1500) { int64_t f2 = POW2(TEMP + 1500); OFF2 += 7 * f2; SENS2 += 11 * f2 >> 1; } TEMP -= T2; _OFF -= OFF2; _SENS -= SENS2; } } else if (_device_type == MS5607_DEVICE) { /* Perform MS5607 Caculation */ _OFF = ((int64_t)_prom.c2_pressure_offset << 17) + (((int64_t)_prom.c4_temp_coeff_pres_offset * dT) >> 6); _SENS = ((int64_t)_prom.c1_pressure_sens << 16) + (((int64_t)_prom.c3_temp_coeff_pres_sens * dT) >> 7); /* MS5607 temperature compensation */ if (TEMP < 2000) { int32_t T2 = POW2(dT) >> 31; int64_t f = POW2((int64_t)TEMP - 2000); int64_t OFF2 = 61 * f >> 4; int64_t SENS2 = 2 * f; if (TEMP < -1500) { int64_t f2 = POW2(TEMP + 1500); OFF2 += 15 * f2; SENS2 += 8 * f2; } TEMP -= T2; _OFF -= OFF2; _SENS -= SENS2; } } float temperature = TEMP / 100.0f; _px4_barometer.set_temperature(temperature); } else { /* pressure calculation, result in Pa */ int32_t P = (((raw * _SENS) >> 21) - _OFF) >> 15; float pressure = P / 100.0f; /* convert to millibar */ _px4_barometer.update(timestamp_sample, pressure); } /* update the measurement state machine */ INCREMENT(_measure_phase, MS5611_MEASUREMENT_RATIO + 1); perf_end(_sample_perf); return OK; } void MS5611::print_status() { I2CSPIDriverBase::print_status(); perf_print_counter(_sample_perf); perf_print_counter(_comms_errors); printf("device: %s\n", _device_type == MS5611_DEVICE ? "ms5611" : "ms5607"); _px4_barometer.print_status(); } namespace ms5611 { /** * MS5611 crc4 cribbed from the datasheet */ bool crc4(uint16_t *n_prom) { int16_t cnt; uint16_t n_rem; uint16_t crc_read; uint8_t n_bit; n_rem = 0x00; /* save the read crc */ crc_read = n_prom[7]; /* remove CRC byte */ n_prom[7] = (0xFF00 & (n_prom[7])); for (cnt = 0; cnt < 16; cnt++) { /* uneven bytes */ if (cnt & 1) { n_rem ^= (uint8_t)((n_prom[cnt >> 1]) & 0x00FF); } else { n_rem ^= (uint8_t)(n_prom[cnt >> 1] >> 8); } for (n_bit = 8; n_bit > 0; n_bit--) { if (n_rem & 0x8000) { n_rem = (n_rem << 1) ^ 0x3000; } else { n_rem = (n_rem << 1); } } } /* final 4 bit remainder is CRC value */ n_rem = (0x000F & (n_rem >> 12)); n_prom[7] = crc_read; /* return true if CRCs match */ return (0x000F & crc_read) == (n_rem ^ 0x00); } } // namespace ms5611