/**************************************************************************** * * 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 mb12xx.cpp * @author Greg Hulands * * Driver for the Maxbotix sonar range finders 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 #include /* Configuration Constants */ #define MB12XX_BUS PX4_I2C_BUS_EXPANSION #define MB12XX_BASEADDR 0x70 /* 7-bit address. 8-bit address is 0xE0 */ /* MB12xx Registers addresses */ #define MB12XX_TAKE_RANGE_REG 0x51 /* Measure range Register */ #define MB12XX_SET_ADDRESS_1 0xAA /* Change address 1 Register */ #define MB12XX_SET_ADDRESS_2 0xA5 /* Change address 2 Register */ /* Device limits */ #define MB12XX_MIN_DISTANCE (0.20f) #define MB12XX_MAX_DISTANCE (7.65f) #define MB12XX_CONVERSION_INTERVAL 60000 /* 60ms */ /* 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 MB12XX : public device::I2C { public: MB12XX(int bus = MB12XX_BUS, int address = MB12XX_BASEADDR); virtual ~MB12XX(); 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: float _min_distance; float _max_distance; work_s _work; RingBuffer *_reports; bool _sensor_ok; int _measure_ticks; bool _collect_phase; orb_advert_t _range_finder_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(); /** * Set the min and max distance thresholds if you want the end points of the sensors * range to be brought in at all, otherwise it will use the defaults MB12XX_MIN_DISTANCE * and MB12XX_MAX_DISTANCE */ void set_minimum_distance(float min); void set_maximum_distance(float max); float get_minimum_distance(); float get_maximum_distance(); /** * 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); }; /* * Driver 'main' command. */ extern "C" __EXPORT int mb12xx_main(int argc, char *argv[]); MB12XX::MB12XX(int bus, int address) : I2C("MB12xx", RANGE_FINDER_DEVICE_PATH, bus, address, 100000), _min_distance(MB12XX_MIN_DISTANCE), _max_distance(MB12XX_MAX_DISTANCE), _reports(nullptr), _sensor_ok(false), _measure_ticks(0), _collect_phase(false), _range_finder_topic(-1), _sample_perf(perf_alloc(PC_ELAPSED, "mb12xx_read")), _comms_errors(perf_alloc(PC_COUNT, "mb12xx_comms_errors")), _buffer_overflows(perf_alloc(PC_COUNT, "mb12xx_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)); } MB12XX::~MB12XX() { /* make sure we are truly inactive */ stop(); /* free any existing reports */ if (_reports != nullptr) delete _reports; } int MB12XX::init() { int ret = ERROR; /* do I2C init (and probe) first */ if (I2C::init() != OK) goto out; /* allocate basic report buffers */ _reports = new RingBuffer(2, sizeof(range_finder_report)); if (_reports == nullptr) goto out; /* get a publish handle on the range finder topic */ struct range_finder_report zero_report; memset(&zero_report, 0, sizeof(zero_report)); _range_finder_topic = orb_advertise(ORB_ID(sensor_range_finder), &zero_report); if (_range_finder_topic < 0) debug("failed to create sensor_range_finder 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 MB12XX::probe() { return measure(); } void MB12XX::set_minimum_distance(float min) { _min_distance = min; } void MB12XX::set_maximum_distance(float max) { _max_distance = max; } float MB12XX::get_minimum_distance() { return _min_distance; } float MB12XX::get_maximum_distance() { return _max_distance; } int MB12XX::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(MB12XX_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(MB12XX_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: { /* lower bound is mandatory, upper bound is a sanity check */ if ((arg < 1) || (arg > 100)) return -EINVAL; irqstate_t flags = irqsave(); if (!_reports->resize(arg)) { irqrestore(flags); return -ENOMEM; } irqrestore(flags); return OK; } case SENSORIOCGQUEUEDEPTH: return _reports->size(); case SENSORIOCRESET: /* XXX implement this */ return -EINVAL; case RANGEFINDERIOCSETMINIUMDISTANCE: { set_minimum_distance(*(float *)arg); return 0; } break; case RANGEFINDERIOCSETMAXIUMDISTANCE: { set_maximum_distance(*(float *)arg); return 0; } break; default: /* give it to the superclass */ return I2C::ioctl(filp, cmd, arg); } } ssize_t MB12XX::read(struct file *filp, char *buffer, size_t buflen) { unsigned count = buflen / sizeof(struct range_finder_report); struct range_finder_report *rbuf = reinterpret_cast(buffer); 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 (_reports->get(rbuf)) { ret += sizeof(*rbuf); rbuf++; } } /* if there was no data, warn the caller */ return ret ? ret : -EAGAIN; } /* manual measurement - run one conversion */ do { _reports->flush(); /* trigger a measurement */ if (OK != measure()) { ret = -EIO; break; } /* wait for it to complete */ usleep(MB12XX_CONVERSION_INTERVAL); /* run the collection phase */ if (OK != collect()) { ret = -EIO; break; } /* state machine will have generated a report, copy it out */ if (_reports->get(rbuf)) { ret = sizeof(*rbuf); } } while (0); return ret; } int MB12XX::measure() { int ret; /* * Send the command to begin a measurement. */ uint8_t cmd = MB12XX_TAKE_RANGE_REG; 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 MB12XX::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); perf_count(_comms_errors); perf_end(_sample_perf); return ret; } uint16_t distance = val[0] << 8 | val[1]; float si_units = (distance * 1.0f)/ 100.0f; /* cm to m */ struct range_finder_report report; /* this should be fairly close to the end of the measurement, so the best approximation of the time */ report.timestamp = hrt_absolute_time(); report.error_count = perf_event_count(_comms_errors); report.distance = si_units; report.valid = si_units > get_minimum_distance() && si_units < get_maximum_distance() ? 1 : 0; /* publish it */ orb_publish(ORB_ID(sensor_range_finder), _range_finder_topic, &report); if (_reports->force(&report)) { perf_count(_buffer_overflows); } /* notify anyone waiting for data */ poll_notify(POLLIN); ret = OK; perf_end(_sample_perf); return ret; } void MB12XX::start() { /* reset the report ring and state machine */ _collect_phase = false; _reports->flush(); /* schedule a cycle to start things */ work_queue(HPWORK, &_work, (worker_t)&MB12XX::cycle_trampoline, this, 1); /* notify about state change */ struct subsystem_info_s info = { true, true, true, SUBSYSTEM_TYPE_RANGEFINDER}; 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 MB12XX::stop() { work_cancel(HPWORK, &_work); } void MB12XX::cycle_trampoline(void *arg) { MB12XX *dev = (MB12XX *)arg; dev->cycle(); } void MB12XX::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(MB12XX_CONVERSION_INTERVAL)) { /* schedule a fresh cycle call when we are ready to measure again */ work_queue(HPWORK, &_work, (worker_t)&MB12XX::cycle_trampoline, this, _measure_ticks - USEC2TICK(MB12XX_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)&MB12XX::cycle_trampoline, this, USEC2TICK(MB12XX_CONVERSION_INTERVAL)); } void MB12XX::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); _reports->print_info("report queue"); } /** * Local functions in support of the shell command. */ namespace mb12xx { /* oddly, ERROR is not defined for c++ */ #ifdef ERROR # undef ERROR #endif const int ERROR = -1; MB12XX *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 MB12XX(MB12XX_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(RANGE_FINDER_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 range_finder_report report; ssize_t sz; int ret; int fd = open(RANGE_FINDER_DEVICE_PATH, O_RDONLY); if (fd < 0) err(1, "%s open failed (try 'mb12xx start' if the driver is not running", RANGE_FINDER_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.distance); 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.distance); warnx("time: %lld", report.timestamp); } errx(0, "PASS"); } /** * Reset the driver. */ void reset() { int fd = open(RANGE_FINDER_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 mb12xx_main(int argc, char *argv[]) { /* * Start/load the driver. */ if (!strcmp(argv[1], "start")) mb12xx::start(); /* * Stop the driver */ if (!strcmp(argv[1], "stop")) mb12xx::stop(); /* * Test the driver/device. */ if (!strcmp(argv[1], "test")) mb12xx::test(); /* * Reset the driver. */ if (!strcmp(argv[1], "reset")) mb12xx::reset(); /* * Print driver information. */ if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status")) mb12xx::info(); errx(1, "unrecognized command, try 'start', 'test', 'reset' or 'info'"); }