From 4f99200b0ff102c01f415a57e9f173a863483d2a Mon Sep 17 00:00:00 2001 From: Simon Wilks Date: Thu, 11 Apr 2013 08:36:54 +0200 Subject: Initial implementation that can read values from the ETS. --- apps/drivers/ets_airspeed/ets_airspeed.cpp | 785 +++++++++++++++++++++++++++++ 1 file changed, 785 insertions(+) create mode 100644 apps/drivers/ets_airspeed/ets_airspeed.cpp (limited to 'apps/drivers/ets_airspeed/ets_airspeed.cpp') diff --git a/apps/drivers/ets_airspeed/ets_airspeed.cpp b/apps/drivers/ets_airspeed/ets_airspeed.cpp new file mode 100644 index 000000000..790e949e0 --- /dev/null +++ b/apps/drivers/ets_airspeed/ets_airspeed.cpp @@ -0,0 +1,785 @@ +/**************************************************************************** + * + * Copyright (C) 2013 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 airspeed.cpp + * @author Simon Wilks + * + * Driver for the Eagle Tree Airspeed V3 connected via I2C. + */ + +#include + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include + +#include +#include + +#include +#include + +#include +#include + + +/* Configuration Constants */ +#define ETS_AIRSPEED_BUS PX4_I2C_BUS_ESC +#define ETS_AIRSPEED_ADDRESS 0x75 + +/* ETS_AIRSPEED Registers addresses */ + +#define ETS_AIRSPEED_READ_CMD 0x07 /* Read the data */ + +/* Max measurement rate is 100Hz */ +#define ETS_AIRSPEED_CONVERSION_INTERVAL (1000000 / 100) /* microseconds */ + +/* 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 + +class ETS_AIRSPEED : public device::I2C +{ +public: + ETS_AIRSPEED(int bus = ETS_AIRSPEED_BUS, int address = ETS_AIRSPEED_ADDRESS); + virtual ~ETS_AIRSPEED(); + + 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: + work_s _work; + unsigned _num_reports; + volatile unsigned _next_report; + volatile unsigned _oldest_report; + airspeed_report *_reports; + bool _sensor_ok; + int _measure_ticks; + bool _collect_phase; + + orb_advert_t _differential_pressure_topic; + + perf_counter_t _sample_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(); + + /** + * Stop the automatic measurement state machine. + */ + void stop(); + + /** + * Perform a poll cycle; collect from the previous measurement + * and start a new one. + */ + void cycle(); + int measure(); + int collect(); + /** + * 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); + + +}; + +/* helper macro for handling report buffer indices */ +#define INCREMENT(_x, _lim) do { _x++; if (_x >= _lim) _x = 0; } while(0) + +/* + * Driver 'main' command. + */ +extern "C" __EXPORT int ets_airspeed_main(int argc, char *argv[]); + +ETS_AIRSPEED::ETS_AIRSPEED(int bus, int address) : + I2C("ETS_AIRSPEED", AIRSPEED_DEVICE_PATH, bus, address, 100000), + _num_reports(0), + _next_report(0), + _oldest_report(0), + _reports(nullptr), + _sensor_ok(false), + _measure_ticks(0), + _collect_phase(false), + _differential_pressure_topic(-1), + _sample_perf(perf_alloc(PC_ELAPSED, "ETS_AIRSPEED_read")), + _comms_errors(perf_alloc(PC_COUNT, "ETS_AIRSPEED_comms_errors")), + _buffer_overflows(perf_alloc(PC_COUNT, "ETS_AIRSPEED_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)); +} + +ETS_AIRSPEED::~ETS_AIRSPEED() +{ + /* make sure we are truly inactive */ + stop(); + + /* free any existing reports */ + if (_reports != nullptr) + delete[] _reports; +} + +int +ETS_AIRSPEED::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 airspeed_report[_num_reports]; + + if (_reports == nullptr) + goto out; + + _oldest_report = _next_report = 0; + + /* get a publish handle on the airspeed topic */ + memset(&_reports[0], 0, sizeof(_reports[0])); + _differential_pressure_topic = orb_advertise(ORB_ID(sensor_differential_pressure), &_reports[0]); + + if (_differential_pressure_topic < 0) + debug("failed to create airspeed sensor object. Did you start uOrb?"); + + ret = OK; + /* sensor is ok, but we don't really know if it is within range */ + _sensor_ok = true; +out: + return ret; +} + +int +ETS_AIRSPEED::probe() +{ + return measure(); +} + +int +ETS_AIRSPEED::ioctl(struct file *filp, int cmd, unsigned long arg) +{ + switch (cmd) { + + case SENSORIOCSPOLLRATE: { + switch (arg) { + + /* switching to manual polling */ + case SENSOR_POLLRATE_MANUAL: + stop(); + _measure_ticks = 0; + return OK; + + /* external signalling (DRDY) 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(ETS_AIRSPEED_CONVERSION_INTERVAL); + + /* if we need to start the poll state machine, do it */ + if (want_start) + start(); + + 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(ETS_AIRSPEED_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(); + + 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 airspeed_report *buf = new struct airspeed_report[arg]; + + if (nullptr == buf) + return -ENOMEM; + + /* reset the measurement state machine with the new buffer, free the old */ + stop(); + delete[] _reports; + _num_reports = arg; + _reports = buf; + start(); + + return OK; + } + + case SENSORIOCGQUEUEDEPTH: + return _num_reports - 1; + + case SENSORIOCRESET: + /* XXX implement this */ + return -EINVAL; + + default: + /* give it to the superclass */ + return I2C::ioctl(filp, cmd, arg); + } +} + +ssize_t +ETS_AIRSPEED::read(struct file *filp, char *buffer, size_t buflen) +{ + unsigned count = buflen / sizeof(struct airspeed_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 { + _oldest_report = _next_report = 0; + + /* trigger a measurement */ + if (OK != measure()) { + ret = -EIO; + break; + } + + /* wait for it to complete */ + usleep(ETS_AIRSPEED_CONVERSION_INTERVAL); + + /* run the collection phase */ + 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 +ETS_AIRSPEED::measure() +{ + int ret; + + /* + * Send the command to begin a measurement. + */ + uint8_t cmd = ETS_AIRSPEED_READ_CMD; + ret = transfer(&cmd, 1, nullptr, 0); + + if (OK != ret) + { + perf_count(_comms_errors); + log("i2c::transfer returned %d", ret); + return ret; + } + ret = OK; + + return ret; +} + +int +ETS_AIRSPEED::collect() +{ + int ret = -EIO; + + /* read from the sensor */ + uint8_t val[2] = {0, 0}; + + perf_begin(_sample_perf); + + ret = transfer(nullptr, 0, &val[0], 2); + + if (ret < 0) + { + log("error reading from sensor: %d", ret); + return ret; + } + + uint16_t distance = val[0] << 8 | val[1]; + float si_units = (distance * 1.0f)/ 100.0f; /* cm to m */ + /* this should be fairly close to the end of the measurement, so the best approximation of the time */ + _reports[_next_report].timestamp = hrt_absolute_time(); + _reports[_next_report].speed = si_units; + + /* publish it */ + orb_publish(ORB_ID(sensor_differential_pressure), _differential_pressure_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); + + ret = OK; + +out: + perf_end(_sample_perf); + return ret; + + return ret; +} + +void +ETS_AIRSPEED::start() +{ + /* reset the report ring and state machine */ + _collect_phase = false; + _oldest_report = _next_report = 0; + + /* schedule a cycle to start things */ + work_queue(HPWORK, &_work, (worker_t)&ETS_AIRSPEED::cycle_trampoline, this, 1); + + /* notify about state change */ + struct subsystem_info_s info = { + true, + true, + true, + SUBSYSTEM_TYPE_DIFFPRESSURE}; + static orb_advert_t pub = -1; + + if (pub > 0) { + orb_publish(ORB_ID(subsystem_info), pub, &info); + } else { + pub = orb_advertise(ORB_ID(subsystem_info), &info); + } +} + +void +ETS_AIRSPEED::stop() +{ + work_cancel(HPWORK, &_work); +} + +void +ETS_AIRSPEED::cycle_trampoline(void *arg) +{ + ETS_AIRSPEED *dev = (ETS_AIRSPEED *)arg; + + dev->cycle(); +} + +void +ETS_AIRSPEED::cycle() +{ + /* collection phase? */ + if (_collect_phase) { + + /* perform collection */ + if (OK != collect()) { + log("collection error"); + /* restart the measurement state machine */ + start(); + return; + } + + /* next phase is measurement */ + _collect_phase = false; + + /* + * Is there a collect->measure gap? + */ + if (_measure_ticks > USEC2TICK(ETS_AIRSPEED_CONVERSION_INTERVAL)) { + + /* schedule a fresh cycle call when we are ready to measure again */ + work_queue(HPWORK, + &_work, + (worker_t)&ETS_AIRSPEED::cycle_trampoline, + this, + _measure_ticks - USEC2TICK(ETS_AIRSPEED_CONVERSION_INTERVAL)); + + return; + } + } + + /* measurement phase */ + if (OK != measure()) + log("measure error"); + + /* next phase is collection */ + _collect_phase = true; + + /* schedule a fresh cycle call when the measurement is done */ + work_queue(HPWORK, + &_work, + (worker_t)&ETS_AIRSPEED::cycle_trampoline, + this, + USEC2TICK(ETS_AIRSPEED_CONVERSION_INTERVAL)); +} + +void +ETS_AIRSPEED::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); +} + +/** + * Local functions in support of the shell command. + */ +namespace ets_airspeed +{ + +/* oddly, ERROR is not defined for c++ */ +#ifdef ERROR +# undef ERROR +#endif +const int ERROR = -1; + +ETS_AIRSPEED *g_dev; + +void start(); +void stop(); +void test(); +void reset(); +void info(); + +/** + * Start the driver. + */ +void +start() +{ + int fd; + + if (g_dev != nullptr) + errx(1, "already started"); + + /* create the driver */ + g_dev = new ETS_AIRSPEED(ETS_AIRSPEED_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(AIRSPEED_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"); +} + +/** + * Stop the driver + */ +void stop() +{ + if (g_dev != nullptr) + { + delete g_dev; + g_dev = nullptr; + } + else + { + errx(1, "driver not running"); + } + 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() +{ + struct airspeed_report report; + ssize_t sz; + int ret; + + int fd = open(AIRSPEED_DEVICE_PATH, O_RDONLY); + + if (fd < 0) + err(1, "%s open failed (try 'ets_airspeed start' if the driver is not running", AIRSPEED_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("measurement: %0.2f m", (double)report.speed); + warnx("time: %lld", report.timestamp); + + /* 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("measurement: %0.3f", (double)report.speed); + warnx("time: %lld", report.timestamp); + } + + errx(0, "PASS"); +} + +/** + * Reset the driver. + */ +void +reset() +{ + int fd = open(AIRSPEED_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); +} + +} // namespace + +int +ets_airspeed_main(int argc, char *argv[]) +{ + /* + * Start/load the driver. + */ + if (!strcmp(argv[1], "start")) + ets_airspeed::start(); + + /* + * Stop the driver + */ + if (!strcmp(argv[1], "stop")) + ets_airspeed::stop(); + + /* + * Test the driver/device. + */ + if (!strcmp(argv[1], "test")) + ets_airspeed::test(); + + /* + * Reset the driver. + */ + if (!strcmp(argv[1], "reset")) + ets_airspeed::reset(); + + /* + * Print driver information. + */ + if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status")) + ets_airspeed::info(); + + errx(1, "unrecognized command, try 'start', 'test', 'reset' or 'info'"); +} -- cgit v1.2.3