From df9547e9d36b4fd167f746dff1b809d2f4bfac3d Mon Sep 17 00:00:00 2001 From: Randy Mackay Date: Tue, 25 Nov 2014 15:03:44 +0900 Subject: batt_smbus: driver for smart battery --- src/drivers/batt_smbus/batt_smbus.cpp | 438 ++++++++++++++++++++++++++++++++++ 1 file changed, 438 insertions(+) create mode 100644 src/drivers/batt_smbus/batt_smbus.cpp (limited to 'src/drivers/batt_smbus/batt_smbus.cpp') diff --git a/src/drivers/batt_smbus/batt_smbus.cpp b/src/drivers/batt_smbus/batt_smbus.cpp new file mode 100644 index 000000000..89abcf838 --- /dev/null +++ b/src/drivers/batt_smbus/batt_smbus.cpp @@ -0,0 +1,438 @@ +/**************************************************************************** + * + * Copyright (C) 2012, 2013 PX4 Development Team. All rights reserved. + * Author: Randy Mackay + * + * 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 batt_smbus.cpp + * + * Driver for a battery monitor connected via SMBus (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 + +#include + +#include +#include +#include +#include + +#define BATT_SMBUS_I2C_BUS PX4_I2C_BUS_EXPANSION +#define BATT_SMBUS_ADDR 0x0B /* I2C address */ +#define BATT_SMBUS_TEMP 0x08 /* temperature register */ +#define BATT_SMBUS_VOLTAGE 0x09 /* voltage register */ +#define BATT_SMBUS_DESIGN_CAPACITY 0x18 /* design capacity register */ +#define BATT_SMBUS_DESIGN_VOLTAGE 0x19 /* design voltage register */ +#define BATT_SMBUS_SERIALNUM 0x1c /* serial number register */ +#define BATT_SMBUS_MANUFACTURE_INFO 0x25 /* cell voltage register */ +#define BATT_SMBUS_CURRENT 0x2a /* current register */ +#define BATT_SMBUS_MEASUREMENT_INTERVAL_MS (1000000 / 10) /* time in microseconds, measure at 10hz */ + +#ifndef CONFIG_SCHED_WORKQUEUE +# error This requires CONFIG_SCHED_WORKQUEUE. +#endif + +class BATT_SMBUS : public device::I2C +{ +public: + BATT_SMBUS(int bus = PX4_I2C_BUS_EXPANSION, uint16_t batt_smbus_addr = BATT_SMBUS_ADDR); + virtual ~BATT_SMBUS(); + + virtual int init(); + virtual int test(); + +protected: + virtual int probe(); // check if the device can be contacted + +private: + + // start periodic reads from the battery + void start(); + + // stop periodic reads from the battery + void stop(); + + // static function that is called by worker queue + static void cycle_trampoline(void *arg); + + // perform a read from the battery + void cycle(); + + // read_reg - read a word from specified register + int read_reg(uint8_t reg, uint16_t &val); + + // read_block - returns number of characters read if successful, zero if unsuccessful + uint8_t read_block(uint8_t reg, uint8_t* data, uint8_t max_len, bool append_zero); + + // internal variables + work_s _work; // work queue for scheduling reads + RingBuffer *_reports; // buffer of recorded voltages, currents + struct battery_status_s _last_report; // last published report, used for test() + orb_advert_t _batt_topic; + orb_id_t _batt_orb_id; +}; + +/* for now, we only support one BATT_SMBUS */ +namespace +{ +BATT_SMBUS *g_batt_smbus; +} + +void batt_smbus_usage(); + +extern "C" __EXPORT int batt_smbus_main(int argc, char *argv[]); + +// constructor +BATT_SMBUS::BATT_SMBUS(int bus, uint16_t batt_smbus_addr) : + I2C("batt_smbus", BATT_SMBUS_DEVICE_PATH, bus, batt_smbus_addr, 400000), + _work{}, + _reports(nullptr), + _batt_topic(-1), + _batt_orb_id(nullptr) +{ + // work_cancel in the dtor will explode if we don't do this... + memset(&_work, 0, sizeof(_work)); +} + +// destructor +BATT_SMBUS::~BATT_SMBUS() +{ + /* make sure we are truly inactive */ + stop(); + + if (_reports != nullptr) { + delete _reports; + } +} + +int +BATT_SMBUS::init() +{ + int ret = ENOTTY; + + // attempt to initialise I2C bus + ret = I2C::init(); + + if (ret != OK) { + errx(1,"failed to init I2C"); + return ret; + } else { + /* allocate basic report buffers */ + _reports = new RingBuffer(2, sizeof(struct battery_status_s)); + if (_reports == nullptr) { + ret = ENOTTY; + } else { + // start work queue + start(); + } + } + + // init orb id + _batt_orb_id = ORB_ID(battery_status); + + return ret; +} + +int +BATT_SMBUS::test() +{ + int sub = orb_subscribe(ORB_ID(battery_status)); + bool updated = false; + struct battery_status_s status; + uint64_t start_time = hrt_absolute_time(); + + // loop for 5 seconds + while ((hrt_absolute_time() - start_time) < 5000000) { + + // display new info that has arrived from the orb + orb_check(sub, &updated); + if (updated) { + if (orb_copy(ORB_ID(battery_status), sub, &status) == OK) { + warnx("V=%4.2f C=%4.2f", status.voltage_v, status.current_a); + } + } + + // sleep for 0.05 seconds + usleep(50000); + } + + return OK; +} + +int +BATT_SMBUS::probe() +{ + // always return OK to ensure device starts + return OK; +} + +// start periodic reads from the battery +void +BATT_SMBUS::start() +{ + /* reset the report ring and state machine */ + _reports->flush(); + + /* schedule a cycle to start things */ + work_queue(HPWORK, &_work, (worker_t)&BATT_SMBUS::cycle_trampoline, this, 1); +} + +// stop periodic reads from the battery +void +BATT_SMBUS::stop() +{ + work_cancel(HPWORK, &_work); +} + +// static function that is called by worker queue +void +BATT_SMBUS::cycle_trampoline(void *arg) +{ + BATT_SMBUS *dev = (BATT_SMBUS *)arg; + + dev->cycle(); +} + +// perform a read from the battery +void +BATT_SMBUS::cycle() +{ + // read data from sensor + struct battery_status_s new_report; + + // set time of reading + new_report.timestamp = hrt_absolute_time(); + + // read voltage + uint16_t tmp; + if (read_reg(BATT_SMBUS_VOLTAGE, tmp) == OK) { + // initialise new_report + memset(&new_report, 0, sizeof(new_report)); + + // convert millivolts to volts + new_report.voltage_v = ((float)tmp) / 1000.0f; + + // To-Do: read current as block from BATT_SMBUS_CURRENT register + + // publish to orb + if (_batt_topic != -1) { + orb_publish(_batt_orb_id, _batt_topic, &new_report); + } else { + _batt_topic = orb_advertise(_batt_orb_id, &new_report); + if (_batt_topic < 0) { + errx(1, "ADVERT FAIL"); + } + } + + // copy report for test() + _last_report = new_report; + + /* post a report to the ring */ + _reports->force(&new_report); + + /* notify anyone waiting for data */ + poll_notify(POLLIN); + } + + /* schedule a fresh cycle call when the measurement is done */ + work_queue(HPWORK, &_work, (worker_t)&BATT_SMBUS::cycle_trampoline, this, USEC2TICK(BATT_SMBUS_MEASUREMENT_INTERVAL_MS)); +} + +int +BATT_SMBUS::read_reg(uint8_t reg, uint16_t &val) +{ + uint8_t buff[2]; + + // short sleep to improve reliability in cases of two consecutive reads + usleep(1); + + // read from register + int ret = transfer(®, 1, buff, 2); + if (ret == OK) { + val = (uint16_t)buff[1] << 8 | (uint16_t)buff[0]; + } + + // return success or failure + return ret; +} + +// read_block - returns number of characters read if successful, zero if unsuccessful +uint8_t BATT_SMBUS::read_block(uint8_t reg, uint8_t* data, uint8_t max_len, bool append_zero) +{ + uint8_t buff[max_len+1]; // buffer to hold results + + usleep(1); + + // read bytes + int ret = transfer(®, 1,buff, max_len+1); + + // return zero on failure + if (ret != OK) { + return 0; + } + + // get length + uint8_t bufflen = buff[0]; + + // sanity check length returned by smbus + if (bufflen == 0 || bufflen > max_len) { + return 0; + } + + // copy data + memcpy(data, &buff[1], bufflen); + + // optionally add zero to end + if (append_zero) { + data[bufflen] = '\0'; + } + + // return success + return bufflen; +} + +///////////////////////// shell functions /////////////////////// + +void +batt_smbus_usage() +{ + warnx("missing command: try 'start', 'test', 'stop'"); + warnx("options:"); + warnx(" -b i2cbus (%d)", BATT_SMBUS_I2C_BUS); + warnx(" -a addr (0x%x)", BATT_SMBUS_ADDR); +} + +int +batt_smbus_main(int argc, char *argv[]) +{ + int i2cdevice = BATT_SMBUS_I2C_BUS; + int batt_smbusadr = BATT_SMBUS_ADDR; /* 7bit */ + + int ch; + + /* jump over start/off/etc and look at options first */ + while ((ch = getopt(argc, argv, "a:b:")) != EOF) { + switch (ch) { + case 'a': + batt_smbusadr = strtol(optarg, NULL, 0); + break; + + case 'b': + i2cdevice = strtol(optarg, NULL, 0); + break; + + default: + batt_smbus_usage(); + exit(0); + } + } + + if (optind >= argc) { + batt_smbus_usage(); + exit(1); + } + + const char *verb = argv[optind]; + + if (!strcmp(verb, "start")) { + if (g_batt_smbus != nullptr) { + errx(1, "already started"); + } else { + // create new global object + g_batt_smbus = new BATT_SMBUS(i2cdevice, batt_smbusadr); + + if (g_batt_smbus == nullptr) { + errx(1, "new failed"); + } + + if (OK != g_batt_smbus->init()) { + delete g_batt_smbus; + g_batt_smbus = nullptr; + errx(1, "init failed"); + } + } + + exit(0); + } + + /* need the driver past this point */ + if (g_batt_smbus == nullptr) { + warnx("not started"); + batt_smbus_usage(); + exit(1); + } + + if (!strcmp(verb, "test")) { + g_batt_smbus->test(); + exit(0); + } + + if (!strcmp(verb, "stop")) { + delete g_batt_smbus; + g_batt_smbus = nullptr; + exit(0); + } + + batt_smbus_usage(); + exit(0); +} -- cgit v1.2.3