diff options
author | Lorenz Meier <lm@inf.ethz.ch> | 2013-04-27 14:06:23 +0200 |
---|---|---|
committer | Lorenz Meier <lm@inf.ethz.ch> | 2013-04-27 14:06:23 +0200 |
commit | 5974c37abba562c1372beb04490014db274fd175 (patch) | |
tree | 5e2822600f54e060d7d4fbe9e022932ca3e955f4 /src/drivers/ms5611/ms5611.cpp | |
parent | 1becedfe011d02120fe68b549f8c3a02e0a979c7 (diff) | |
download | px4-firmware-5974c37abba562c1372beb04490014db274fd175.tar.gz px4-firmware-5974c37abba562c1372beb04490014db274fd175.tar.bz2 px4-firmware-5974c37abba562c1372beb04490014db274fd175.zip |
Moved the bulk of sensor drivers to the new world
Diffstat (limited to 'src/drivers/ms5611/ms5611.cpp')
-rw-r--r-- | src/drivers/ms5611/ms5611.cpp | 1214 |
1 files changed, 1214 insertions, 0 deletions
diff --git a/src/drivers/ms5611/ms5611.cpp b/src/drivers/ms5611/ms5611.cpp new file mode 100644 index 000000000..59ab5936e --- /dev/null +++ b/src/drivers/ms5611/ms5611.cpp @@ -0,0 +1,1214 @@ +/**************************************************************************** + * + * Copyright (C) 2012 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 barometric pressure sensor connected via I2C. + */ + +#include <nuttx/config.h> + +#include <drivers/device/i2c.h> + +#include <sys/types.h> +#include <stdint.h> +#include <stdbool.h> +#include <stdlib.h> +#include <semaphore.h> +#include <string.h> +#include <fcntl.h> +#include <poll.h> +#include <errno.h> +#include <stdio.h> +#include <math.h> +#include <unistd.h> + +#include <nuttx/arch.h> +#include <nuttx/wqueue.h> +#include <nuttx/clock.h> + +#include <arch/board/board.h> + +#include <drivers/drv_hrt.h> + +#include <systemlib/perf_counter.h> +#include <systemlib/err.h> + +#include <drivers/drv_baro.h> + +/* oddly, ERROR is not defined for c++ */ +#ifdef ERROR +# undef ERROR +#endif +static const int ERROR = -1; + +#ifndef CONFIG_SCHED_WORKQUEUE +# error This requires CONFIG_SCHED_WORKQUEUE. +#endif + +/** + * Calibration PROM as reported by the device. + */ +#pragma pack(push,1) +struct ms5611_prom_s { + uint16_t factory_setup; + uint16_t c1_pressure_sens; + uint16_t c2_pressure_offset; + uint16_t c3_temp_coeff_pres_sens; + uint16_t c4_temp_coeff_pres_offset; + uint16_t c5_reference_temp; + uint16_t c6_temp_coeff_temp; + uint16_t serial_and_crc; +}; + +/** + * Grody hack for crc4() + */ +union ms5611_prom_u { + uint16_t c[8]; + struct ms5611_prom_s s; +}; +#pragma pack(pop) + +class MS5611 : public device::I2C +{ +public: + MS5611(int bus); + virtual ~MS5611(); + + virtual int init(); + + virtual ssize_t read(struct file *filp, char *buffer, size_t buflen); + virtual int ioctl(struct file *filp, int cmd, unsigned long arg); + + /** + * Diagnostics - print some basic information about the driver. + */ + void print_info(); + +protected: + virtual int probe(); + +private: + union ms5611_prom_u _prom; + + struct work_s _work; + unsigned _measure_ticks; + + unsigned _num_reports; + volatile unsigned _next_report; + volatile unsigned _oldest_report; + struct baro_report *_reports; + + bool _collect_phase; + unsigned _measure_phase; + + /* intermediate temperature values per MS5611 datasheet */ + int32_t _TEMP; + int64_t _OFF; + int64_t _SENS; + + /* altitude conversion calibration */ + unsigned _msl_pressure; /* in kPa */ + + orb_advert_t _baro_topic; + + perf_counter_t _sample_perf; + perf_counter_t _measure_perf; + perf_counter_t _comms_errors; + perf_counter_t _buffer_overflows; + + /** + * Test whether the device supported by the driver is present at a + * specific address. + * + * @param address The I2C bus address to probe. + * @return True if the device is present. + */ + int probe_address(uint8_t address); + + /** + * Initialise the automatic measurement state machine and start it. + * + * @note This function is called at open and error time. It might make sense + * to make it more aggressive about resetting the bus in case of errors. + */ + void start_cycle(); + + /** + * Stop the automatic measurement state machine. + */ + void stop_cycle(); + + /** + * Perform a poll cycle; collect from the previous measurement + * and start a new one. + * + * This is the heart of the measurement state machine. This function + * alternately starts a measurement, or collects the data from the + * previous measurement. + * + * When the interval between measurements is greater than the minimum + * measurement interval, a gap is inserted between collection + * and measurement to provide the most recent measurement possible + * at the next interval. + */ + void cycle(); + + /** + * Static trampoline from the workq context; because we don't have a + * generic workq wrapper yet. + * + * @param arg Instance pointer for the driver that is polling. + */ + static void cycle_trampoline(void *arg); + + /** + * Issue a measurement command for the current state. + * + * @return OK if the measurement command was successful. + */ + int measure(); + + /** + * Collect the result of the most recent measurement. + */ + int collect(); + + /** + * Send a reset command to the MS5611. + * + * This is required after any bus reset. + */ + int cmd_reset(); + + /** + * Read the MS5611 PROM + * + * @return OK if the PROM reads successfully. + */ + int read_prom(); + + /** + * PROM CRC routine ported from MS5611 application note + * + * @param n_prom Pointer to words read from PROM. + * @return True if the CRC matches. + */ + bool crc4(uint16_t *n_prom); + +}; + +/* helper macro for handling report buffer indices */ +#define INCREMENT(_x, _lim) do { _x++; if (_x >= _lim) _x = 0; } while(0) + +/* helper macro for arithmetic - returns the square of the argument */ +#define POW2(_x) ((_x) * (_x)) + +/* + * MS5611 internal constants and data structures. + */ + +/* internal conversion time: 9.17 ms, so should not be read at rates higher than 100 Hz */ +#define MS5611_CONVERSION_INTERVAL 10000 /* microseconds */ +#define MS5611_MEASUREMENT_RATIO 3 /* pressure measurements per temperature measurement */ + +#define MS5611_BUS PX4_I2C_BUS_ONBOARD +#define MS5611_ADDRESS_1 PX4_I2C_OBDEV_MS5611 /* address select pins pulled high (PX4FMU series v1.6+) */ +#define MS5611_ADDRESS_2 0x77 /* address select pins pulled low (PX4FMU prototypes) */ + +#define ADDR_RESET_CMD 0x1E /* write to this address to reset chip */ +#define ADDR_CMD_CONVERT_D1 0x48 /* write to this address to start temperature conversion */ +#define ADDR_CMD_CONVERT_D2 0x58 /* write to this address to start pressure conversion */ +#define ADDR_DATA 0x00 /* address of 3 bytes / 32bit pressure data */ +#define ADDR_PROM_SETUP 0xA0 /* address of 8x 2 bytes factory and calibration data */ +#define ADDR_PROM_C1 0xA2 /* address of 6x 2 bytes calibration data */ + +/* + * Driver 'main' command. + */ +extern "C" __EXPORT int ms5611_main(int argc, char *argv[]); + + +MS5611::MS5611(int bus) : + I2C("MS5611", BARO_DEVICE_PATH, bus, 0, 400000), + _measure_ticks(0), + _num_reports(0), + _next_report(0), + _oldest_report(0), + _reports(nullptr), + _collect_phase(false), + _measure_phase(0), + _TEMP(0), + _OFF(0), + _SENS(0), + _msl_pressure(101325), + _baro_topic(-1), + _sample_perf(perf_alloc(PC_ELAPSED, "ms5611_read")), + _measure_perf(perf_alloc(PC_ELAPSED, "ms5611_measure")), + _comms_errors(perf_alloc(PC_COUNT, "ms5611_comms_errors")), + _buffer_overflows(perf_alloc(PC_COUNT, "ms5611_buffer_overflows")) +{ + // enable debug() calls + _debug_enabled = true; + + // work_cancel in the dtor will explode if we don't do this... + memset(&_work, 0, sizeof(_work)); +} + +MS5611::~MS5611() +{ + /* make sure we are truly inactive */ + stop_cycle(); + + /* free any existing reports */ + if (_reports != nullptr) + delete[] _reports; +} + +int +MS5611::init() +{ + int ret = ERROR; + + /* do I2C init (and probe) first */ + if (I2C::init() != OK) + goto out; + + /* allocate basic report buffers */ + _num_reports = 2; + _reports = new struct baro_report[_num_reports]; + + if (_reports == nullptr) + goto out; + + _oldest_report = _next_report = 0; + + /* get a publish handle on the baro topic */ + memset(&_reports[0], 0, sizeof(_reports[0])); + _baro_topic = orb_advertise(ORB_ID(sensor_baro), &_reports[0]); + + if (_baro_topic < 0) + debug("failed to create sensor_baro object"); + + ret = OK; +out: + return ret; +} + +int +MS5611::probe() +{ + _retries = 10; + + if ((OK == probe_address(MS5611_ADDRESS_1)) || + (OK == probe_address(MS5611_ADDRESS_2))) { + /* + * Disable retries; we may enable them selectively in some cases, + * but the device gets confused if we retry some of the commands. + */ + _retries = 0; + return OK; + } + + return -EIO; +} + +int +MS5611::probe_address(uint8_t address) +{ + /* select the address we are going to try */ + set_address(address); + + /* send reset command */ + if (OK != cmd_reset()) + return -EIO; + + /* read PROM */ + if (OK != read_prom()) + return -EIO; + + return OK; +} + +ssize_t +MS5611::read(struct file *filp, char *buffer, size_t buflen) +{ + unsigned count = buflen / sizeof(struct baro_report); + int ret = 0; + + /* buffer must be large enough */ + if (count < 1) + return -ENOSPC; + + /* if automatic measurement is enabled */ + if (_measure_ticks > 0) { + + /* + * While there is space in the caller's buffer, and reports, copy them. + * Note that we may be pre-empted by the workq thread while we are doing this; + * we are careful to avoid racing with them. + */ + while (count--) { + if (_oldest_report != _next_report) { + memcpy(buffer, _reports + _oldest_report, sizeof(*_reports)); + ret += sizeof(_reports[0]); + INCREMENT(_oldest_report, _num_reports); + } + } + + /* if there was no data, warn the caller */ + return ret ? ret : -EAGAIN; + } + + /* manual measurement - run one conversion */ + /* XXX really it'd be nice to lock against other readers here */ + do { + _measure_phase = 0; + _oldest_report = _next_report = 0; + + /* do temperature first */ + if (OK != measure()) { + ret = -EIO; + break; + } + + usleep(MS5611_CONVERSION_INTERVAL); + + if (OK != collect()) { + ret = -EIO; + break; + } + + /* now do a pressure measurement */ + if (OK != measure()) { + ret = -EIO; + break; + } + + usleep(MS5611_CONVERSION_INTERVAL); + + if (OK != collect()) { + ret = -EIO; + break; + } + + /* state machine will have generated a report, copy it out */ + memcpy(buffer, _reports, sizeof(*_reports)); + ret = sizeof(*_reports); + + } while (0); + + return ret; +} + +int +MS5611::ioctl(struct file *filp, int cmd, unsigned long arg) +{ + switch (cmd) { + + case SENSORIOCSPOLLRATE: { + switch (arg) { + + /* switching to manual polling */ + case SENSOR_POLLRATE_MANUAL: + stop_cycle(); + _measure_ticks = 0; + return OK; + + /* external signalling not supported */ + case SENSOR_POLLRATE_EXTERNAL: + + /* zero would be bad */ + case 0: + return -EINVAL; + + /* set default/max polling rate */ + case SENSOR_POLLRATE_MAX: + case SENSOR_POLLRATE_DEFAULT: { + /* do we need to start internal polling? */ + bool want_start = (_measure_ticks == 0); + + /* set interval for next measurement to minimum legal value */ + _measure_ticks = USEC2TICK(MS5611_CONVERSION_INTERVAL); + + /* if we need to start the poll state machine, do it */ + if (want_start) + start_cycle(); + + return OK; + } + + /* adjust to a legal polling interval in Hz */ + default: { + /* do we need to start internal polling? */ + bool want_start = (_measure_ticks == 0); + + /* convert hz to tick interval via microseconds */ + unsigned ticks = USEC2TICK(1000000 / arg); + + /* check against maximum rate */ + if (ticks < USEC2TICK(MS5611_CONVERSION_INTERVAL)) + return -EINVAL; + + /* update interval for next measurement */ + _measure_ticks = ticks; + + /* if we need to start the poll state machine, do it */ + if (want_start) + start_cycle(); + + return OK; + } + } + } + + case SENSORIOCGPOLLRATE: + if (_measure_ticks == 0) + return SENSOR_POLLRATE_MANUAL; + + return (1000 / _measure_ticks); + + case SENSORIOCSQUEUEDEPTH: { + /* add one to account for the sentinel in the ring */ + arg++; + + /* lower bound is mandatory, upper bound is a sanity check */ + if ((arg < 2) || (arg > 100)) + return -EINVAL; + + /* allocate new buffer */ + struct baro_report *buf = new struct baro_report[arg]; + + if (nullptr == buf) + return -ENOMEM; + + /* reset the measurement state machine with the new buffer, free the old */ + stop_cycle(); + delete[] _reports; + _num_reports = arg; + _reports = buf; + start_cycle(); + + return OK; + } + + case SENSORIOCGQUEUEDEPTH: + return _num_reports - 1; + + case SENSORIOCRESET: + /* XXX implement this */ + return -EINVAL; + + case BAROIOCSMSLPRESSURE: + + /* range-check for sanity */ + if ((arg < 80000) || (arg > 120000)) + return -EINVAL; + + _msl_pressure = arg; + return OK; + + case BAROIOCGMSLPRESSURE: + return _msl_pressure; + + default: + break; + } + + /* give it to the superclass */ + return I2C::ioctl(filp, cmd, arg); +} + +void +MS5611::start_cycle() +{ + + /* reset the report ring and state machine */ + _collect_phase = false; + _measure_phase = 0; + _oldest_report = _next_report = 0; + + /* schedule a cycle to start things */ + work_queue(HPWORK, &_work, (worker_t)&MS5611::cycle_trampoline, this, 1); +} + +void +MS5611::stop_cycle() +{ + work_cancel(HPWORK, &_work); +} + +void +MS5611::cycle_trampoline(void *arg) +{ + MS5611 *dev = (MS5611 *)arg; + + dev->cycle(); +} + +void +MS5611::cycle() +{ + int ret; + + /* 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 the message. + */ + } else { + //log("collection error %d", ret); + } + /* reset the collection state machine and try again */ + start_cycle(); + return; + } + + /* next phase is measurement */ + _collect_phase = false; + + /* + * Is there a collect->measure gap? + * Don't inject one after temperature measurements, so we can keep + * doing pressure measurements at something close to the desired rate. + */ + if ((_measure_phase != 0) && + (_measure_ticks > USEC2TICK(MS5611_CONVERSION_INTERVAL))) { + + /* schedule a fresh cycle call when we are ready to measure again */ + work_queue(HPWORK, + &_work, + (worker_t)&MS5611::cycle_trampoline, + this, + _measure_ticks - USEC2TICK(MS5611_CONVERSION_INTERVAL)); + + return; + } + } + + /* measurement phase */ + ret = measure(); + if (ret != OK) { + //log("measure error %d", ret); + /* reset the collection state machine and try again */ + start_cycle(); + return; + } + + /* next phase is collection */ + _collect_phase = true; + + /* schedule a fresh cycle call when the measurement is done */ + work_queue(HPWORK, + &_work, + (worker_t)&MS5611::cycle_trampoline, + this, + USEC2TICK(MS5611_CONVERSION_INTERVAL)); +} + +int +MS5611::measure() +{ + int ret; + + perf_begin(_measure_perf); + + /* + * In phase zero, request temperature; in other phases, request pressure. + */ + uint8_t cmd_data = (_measure_phase == 0) ? ADDR_CMD_CONVERT_D2 : ADDR_CMD_CONVERT_D1; + + /* + * Send the command to begin measuring. + * + * Disable retries on this command; we can't know whether failure + * means the device did or did not see the write. + */ + _retries = 0; + ret = transfer(&cmd_data, 1, nullptr, 0); + + if (OK != ret) + perf_count(_comms_errors); + + perf_end(_measure_perf); + + return ret; +} + +int +MS5611::collect() +{ + int ret; + uint8_t cmd; + uint8_t data[3]; + union { + uint8_t b[4]; + uint32_t w; + } cvt; + + /* read the most recent measurement */ + cmd = 0; + + perf_begin(_sample_perf); + + /* this should be fairly close to the end of the conversion, so the best approximation of the time */ + _reports[_next_report].timestamp = hrt_absolute_time(); + + ret = transfer(&cmd, 1, &data[0], 3); + if (ret != OK) { + perf_count(_comms_errors); + perf_end(_sample_perf); + return ret; + } + + /* fetch the raw value */ + cvt.b[0] = data[2]; + cvt.b[1] = data[1]; + cvt.b[2] = data[0]; + cvt.b[3] = 0; + uint32_t raw = cvt.w; + + /* handle a measurement */ + if (_measure_phase == 0) { + + /* temperature offset (in ADC units) */ + int32_t dT = (int32_t)raw - ((int32_t)_prom.s.c5_reference_temp << 8); + + /* absolute temperature in centidegrees - note intermediate value is outside 32-bit range */ + _TEMP = 2000 + (int32_t)(((int64_t)dT * _prom.s.c6_temp_coeff_temp) >> 23); + + /* base sensor scale/offset values */ + _SENS = ((int64_t)_prom.s.c1_pressure_sens << 15) + (((int64_t)_prom.s.c3_temp_coeff_pres_sens * dT) >> 8); + _OFF = ((int64_t)_prom.s.c2_pressure_offset << 16) + (((int64_t)_prom.s.c4_temp_coeff_pres_offset * dT) >> 7); + + /* 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 { + + /* pressure calculation, result in Pa */ + int32_t P = (((raw * _SENS) >> 21) - _OFF) >> 15; + + /* generate a new report */ + _reports[_next_report].temperature = _TEMP / 100.0f; + _reports[_next_report].pressure = P / 100.0f; /* convert to millibar */ + + /* altitude calculations based on http://www.kansasflyer.org/index.asp?nav=Avi&sec=Alti&tab=Theory&pg=1 */ + + /* + * PERFORMANCE HINT: + * + * The single precision calculation is 50 microseconds faster than the double + * precision variant. It is however not obvious if double precision is required. + * Pending more inspection and tests, we'll leave the double precision variant active. + * + * Measurements: + * double precision: ms5611_read: 992 events, 258641us elapsed, min 202us max 305us + * single precision: ms5611_read: 963 events, 208066us elapsed, min 202us max 241us + */ +#if 0/* USE_FLOAT */ + /* tropospheric properties (0-11km) for standard atmosphere */ + const float T1 = 15.0f + 273.15f; /* temperature at base height in Kelvin */ + const float a = -6.5f / 1000f; /* temperature gradient in degrees per metre */ + const float g = 9.80665f; /* gravity constant in m/s/s */ + const float R = 287.05f; /* ideal gas constant in J/kg/K */ + + /* current pressure at MSL in kPa */ + float p1 = _msl_pressure / 1000.0f; + + /* measured pressure in kPa */ + float p = P / 1000.0f; + + /* + * Solve: + * + * / -(aR / g) \ + * | (p / p1) . T1 | - T1 + * \ / + * h = ------------------------------- + h1 + * a + */ + _reports[_next_report].altitude = (((powf((p / p1), (-(a * R) / g))) * T1) - T1) / a; +#else + /* tropospheric properties (0-11km) for standard atmosphere */ + 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 */ + + /* current pressure at MSL in kPa */ + double p1 = _msl_pressure / 1000.0; + + /* measured pressure in kPa */ + double p = P / 1000.0; + + /* + * Solve: + * + * / -(aR / g) \ + * | (p / p1) . T1 | - T1 + * \ / + * h = ------------------------------- + h1 + * a + */ + _reports[_next_report].altitude = (((pow((p / p1), (-(a * R) / g))) * T1) - T1) / a; +#endif + /* publish it */ + orb_publish(ORB_ID(sensor_baro), _baro_topic, &_reports[_next_report]); + + /* post a report to the ring - note, not locked */ + INCREMENT(_next_report, _num_reports); + + /* if we are running up against the oldest report, toss it */ + if (_next_report == _oldest_report) { + perf_count(_buffer_overflows); + INCREMENT(_oldest_report, _num_reports); + } + + /* notify anyone waiting for data */ + poll_notify(POLLIN); + } + + /* update the measurement state machine */ + INCREMENT(_measure_phase, MS5611_MEASUREMENT_RATIO + 1); + + perf_end(_sample_perf); + + return OK; +} + +int +MS5611::cmd_reset() +{ + unsigned old_retrycount = _retries; + uint8_t cmd = ADDR_RESET_CMD; + int result; + + /* bump the retry count */ + _retries = 10; + result = transfer(&cmd, 1, nullptr, 0); + _retries = old_retrycount; + + return result; +} + +int +MS5611::read_prom() +{ + uint8_t prom_buf[2]; + union { + uint8_t b[2]; + uint16_t w; + } cvt; + + /* + * Wait for PROM contents to be in the device (2.8 ms) in the case we are + * called immediately after reset. + */ + usleep(3000); + + /* read and convert PROM words */ + for (int i = 0; i < 8; i++) { + uint8_t cmd = ADDR_PROM_SETUP + (i * 2); + + if (OK != transfer(&cmd, 1, &prom_buf[0], 2)) + break; + + /* assemble 16 bit value and convert from big endian (sensor) to little endian (MCU) */ + cvt.b[0] = prom_buf[1]; + cvt.b[1] = prom_buf[0]; + _prom.c[i] = cvt.w; + } + + /* calculate CRC and return success/failure accordingly */ + return crc4(&_prom.c[0]) ? OK : -EIO; +} + +bool +MS5611::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); +} + +void +MS5611::print_info() +{ + perf_print_counter(_sample_perf); + perf_print_counter(_comms_errors); + perf_print_counter(_buffer_overflows); + printf("poll interval: %u ticks\n", _measure_ticks); + printf("report queue: %u (%u/%u @ %p)\n", + _num_reports, _oldest_report, _next_report, _reports); + printf("TEMP: %d\n", _TEMP); + printf("SENS: %lld\n", _SENS); + printf("OFF: %lld\n", _OFF); + printf("MSL pressure: %10.4f\n", (double)(_msl_pressure / 100.f)); + + printf("factory_setup %u\n", _prom.s.factory_setup); + printf("c1_pressure_sens %u\n", _prom.s.c1_pressure_sens); + printf("c2_pressure_offset %u\n", _prom.s.c2_pressure_offset); + printf("c3_temp_coeff_pres_sens %u\n", _prom.s.c3_temp_coeff_pres_sens); + printf("c4_temp_coeff_pres_offset %u\n", _prom.s.c4_temp_coeff_pres_offset); + printf("c5_reference_temp %u\n", _prom.s.c5_reference_temp); + printf("c6_temp_coeff_temp %u\n", _prom.s.c6_temp_coeff_temp); + printf("serial_and_crc %u\n", _prom.s.serial_and_crc); +} + +/** + * Local functions in support of the shell command. + */ +namespace ms5611 +{ + +MS5611 *g_dev; + +void start(); +void test(); +void reset(); +void info(); +void calibrate(unsigned altitude); + +/** + * Start the driver. + */ +void +start() +{ + int fd; + + if (g_dev != nullptr) + errx(1, "already started"); + + /* create the driver */ + g_dev = new MS5611(MS5611_BUS); + + if (g_dev == nullptr) + goto fail; + + if (OK != g_dev->init()) + goto fail; + + /* set the poll rate to default, starts automatic data collection */ + fd = open(BARO_DEVICE_PATH, 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; + } + + errx(1, "driver start failed"); +} + +/** + * Perform some basic functional tests on the driver; + * make sure we can collect data from the sensor in polled + * and automatic modes. + */ +void +test() +{ + struct baro_report report; + ssize_t sz; + int ret; + + int fd = open(BARO_DEVICE_PATH, O_RDONLY); + + if (fd < 0) + err(1, "%s open failed (try 'ms5611 start' if the driver is not running)", BARO_DEVICE_PATH); + + /* do a simple demand read */ + sz = read(fd, &report, sizeof(report)); + + if (sz != sizeof(report)) + err(1, "immediate read failed"); + + warnx("single read"); + warnx("pressure: %10.4f", (double)report.pressure); + warnx("altitude: %11.4f", (double)report.altitude); + warnx("temperature: %8.4f", (double)report.temperature); + warnx("time: %lld", report.timestamp); + + /* set the queue depth to 10 */ + if (OK != ioctl(fd, SENSORIOCSQUEUEDEPTH, 10)) + errx(1, "failed to set queue depth"); + + /* start the sensor polling at 2Hz */ + if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) + errx(1, "failed to set 2Hz poll rate"); + + /* 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; + ret = poll(&fds, 1, 2000); + + if (ret != 1) + errx(1, "timed out waiting for sensor data"); + + /* now go get it */ + sz = read(fd, &report, sizeof(report)); + + if (sz != sizeof(report)) + err(1, "periodic read failed"); + + warnx("periodic read %u", i); + warnx("pressure: %10.4f", (double)report.pressure); + warnx("altitude: %11.4f", (double)report.altitude); + warnx("temperature: %8.4f", (double)report.temperature); + warnx("time: %lld", report.timestamp); + } + + errx(0, "PASS"); +} + +/** + * Reset the driver. + */ +void +reset() +{ + int fd = open(BARO_DEVICE_PATH, O_RDONLY); + + if (fd < 0) + err(1, "failed "); + + if (ioctl(fd, SENSORIOCRESET, 0) < 0) + err(1, "driver reset failed"); + + if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0) + err(1, "driver poll restart failed"); + + exit(0); +} + +/** + * Print a little info about the driver. + */ +void +info() +{ + if (g_dev == nullptr) + errx(1, "driver not running"); + + printf("state @ %p\n", g_dev); + g_dev->print_info(); + + exit(0); +} + +/** + * Calculate actual MSL pressure given current altitude + */ +void +calibrate(unsigned altitude) +{ + struct baro_report report; + float pressure; + float p1; + + int fd = open(BARO_DEVICE_PATH, O_RDONLY); + + if (fd < 0) + err(1, "%s open failed (try 'ms5611 start' if the driver is not running)", BARO_DEVICE_PATH); + + /* start the sensor polling at max */ + if (OK != ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_MAX)) + errx(1, "failed to set poll rate"); + + /* average a few measurements */ + pressure = 0.0f; + + for (unsigned i = 0; i < 20; i++) { + struct pollfd fds; + int ret; + ssize_t sz; + + /* wait for data to be ready */ + fds.fd = fd; + fds.events = POLLIN; + ret = poll(&fds, 1, 1000); + + if (ret != 1) + errx(1, "timed out waiting for sensor data"); + + /* now go get it */ + sz = read(fd, &report, sizeof(report)); + + if (sz != sizeof(report)) + err(1, "sensor read failed"); + + pressure += report.pressure; + } + + pressure /= 20; /* average */ + pressure /= 10; /* scale from millibar to kPa */ + + /* tropospheric properties (0-11km) for standard atmosphere */ + const float T1 = 15.0 + 273.15; /* temperature at base height in Kelvin */ + const float a = -6.5 / 1000; /* temperature gradient in degrees per metre */ + const float g = 9.80665f; /* gravity constant in m/s/s */ + const float R = 287.05f; /* ideal gas constant in J/kg/K */ + + warnx("averaged pressure %10.4fkPa at %um", pressure, altitude); + + p1 = pressure * (powf(((T1 + (a * (float)altitude)) / T1), (g / (a * R)))); + + warnx("calculated MSL pressure %10.4fkPa", p1); + + /* save as integer Pa */ + p1 *= 1000.0f; + + if (ioctl(fd, BAROIOCSMSLPRESSURE, (unsigned long)p1) != OK) + err(1, "BAROIOCSMSLPRESSURE"); + + exit(0); +} + +} // namespace + +int +ms5611_main(int argc, char *argv[]) +{ + /* + * Start/load the driver. + */ + if (!strcmp(argv[1], "start")) + ms5611::start(); + + /* + * Test the driver/device. + */ + if (!strcmp(argv[1], "test")) + ms5611::test(); + + /* + * Reset the driver. + */ + if (!strcmp(argv[1], "reset")) + ms5611::reset(); + + /* + * Print driver information. + */ + if (!strcmp(argv[1], "info")) + ms5611::info(); + + /* + * Perform MSL pressure calibration given an altitude in metres + */ + if (!strcmp(argv[1], "calibrate")) { + if (argc < 2) + errx(1, "missing altitude"); + + long altitude = strtol(argv[2], nullptr, 10); + + ms5611::calibrate(altitude); + } + + errx(1, "unrecognised command, try 'start', 'test', 'reset' or 'info'"); +} |