ardupilot/libraries/AP_Baro/AP_Baro_LPS2XH.cpp

/*
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "AP_Baro_LPS2XH.h"

#if AP_BARO_LPS2XH_ENABLED

#include <utility>
#include <stdio.h>

#include <AP_InertialSensor/AP_InertialSensor_Invensense_registers.h>

extern const AP_HAL::HAL &hal;

// WHOAMI values
#define LPS22HB_WHOAMI 0xB1
#define LPS25HB_WHOAMI 0xBD

#define REG_ID                     0x0F

#define LPS22H_ID                  0xB1
#define LPS22H_CTRL_REG1           0x10
#define LPS22H_CTRL_REG2           0x11
#define LPS22H_CTRL_REG3           0x12

#define LPS22H_CTRL_REG1_SIM       (1 << 0)
#define LPS22H_CTRL_REG1_BDU       (1 << 1)
#define LPS22H_CTRL_REG1_LPFP_CFG  (1 << 2)
#define LPS22H_CTRL_REG1_EN_LPFP   (1 << 3)
#define LPS22H_CTRL_REG1_PD        (0 << 4)
#define LPS22H_CTRL_REG1_ODR_1H    (1 << 4)
#define LPS22H_CTRL_REG1_ODR_10HZ  (2 << 4)
#define LPS22H_CTRL_REG1_ODR_25HZ  (3 << 4)
#define LPS22H_CTRL_REG1_ODR_50HZ  (4 << 4)
#define LPS22H_CTRL_REG1_ODR_75HZ  (5 << 4)

#define LPS25H_CTRL_REG1_ADDR      0x20
#define LPS25H_CTRL_REG2_ADDR      0x21
#define LPS25H_CTRL_REG3_ADDR      0x22
#define LPS25H_CTRL_REG4_ADDR      0x23
#define LPS25H_FIFO_CTRL           0x2E
#define TEMP_OUT_ADDR      		   0x2B
#define PRESS_OUT_XL_ADDR		   0x28
#define STATUS_ADDR		  		   0x27

//putting 1 in the MSB of those two registers turns on Auto increment for faster reading.

AP_Baro_LPS2XH::AP_Baro_LPS2XH(AP_Baro &baro, AP_HAL::OwnPtr<AP_HAL::Device> dev)
    : AP_Baro_Backend(baro)
    , _dev(std::move(dev))
{
}

AP_Baro_Backend *AP_Baro_LPS2XH::probe(AP_Baro &baro,
                                       AP_HAL::OwnPtr<AP_HAL::Device> dev)
{
    if (!dev) {
        return nullptr;
    }

    AP_Baro_LPS2XH *sensor = new AP_Baro_LPS2XH(baro, std::move(dev));
    if (!sensor || !sensor->_init()) {
        delete sensor;
        return nullptr;
    }

    return sensor;
}

AP_Baro_Backend *AP_Baro_LPS2XH::probe_InvensenseIMU(AP_Baro &baro,
                                                     AP_HAL::OwnPtr<AP_HAL::Device> dev,
                                                     uint8_t imu_address)
{
    if (!dev) {
        return nullptr;
    }

    AP_Baro_LPS2XH *sensor = new AP_Baro_LPS2XH(baro, std::move(dev));
    if (sensor) {
        if (!sensor->_imu_i2c_init(imu_address)) {
            delete sensor;
            return nullptr;
        }
    }

    if (!sensor || !sensor->_init()) {
        delete sensor;
        return nullptr;
    }

    return sensor;
}

/*
  setup invensense IMU to enable barometer, assuming both IMU and baro
  on the same i2c bus
*/
bool AP_Baro_LPS2XH::_imu_i2c_init(uint8_t imu_address)
{
    _dev->get_semaphore()->take_blocking();

    // as the baro device is already locked we need to re-use it,
    // changing its address to match the IMU address
    uint8_t old_address = _dev->get_bus_address();
    _dev->set_address(imu_address);

    _dev->set_retries(4);

    uint8_t whoami=0;
    _dev->read_registers(MPUREG_WHOAMI, &whoami, 1);
    DEV_PRINTF("IMU: whoami 0x%02x old_address=%02x\n", whoami, old_address);

    _dev->write_register(MPUREG_FIFO_EN, 0x00);
    _dev->write_register(MPUREG_PWR_MGMT_1, BIT_PWR_MGMT_1_CLK_XGYRO);

    // wait for sensor to settle
    hal.scheduler->delay(10);

    _dev->write_register(MPUREG_INT_PIN_CFG, BIT_BYPASS_EN);

    _dev->set_address(old_address);

    _dev->get_semaphore()->give();

    return true;
}

bool AP_Baro_LPS2XH::_init()
{
    if (!_dev) {
        return false;
    }
    _dev->get_semaphore()->take_blocking();

    _dev->set_speed(AP_HAL::Device::SPEED_HIGH);

    // top bit is for read on SPI
    if (_dev->bus_type() == AP_HAL::Device::BUS_TYPE_SPI) {
        _dev->set_read_flag(0x80);
    }

    if (!_check_whoami()) {
        _dev->get_semaphore()->give();
        return false;
    }

    //init control registers.
    if (_lps2xh_type == BARO_LPS25H) {
    	_dev->write_register(LPS25H_CTRL_REG1_ADDR,0x00); // turn off for config
    	_dev->write_register(LPS25H_CTRL_REG2_ADDR,0x00); //FIFO Disabled
    	_dev->write_register(LPS25H_FIFO_CTRL, 0x01);
    	_dev->write_register(LPS25H_CTRL_REG1_ADDR,0xc0);

    	// request 25Hz update (maximum refresh Rate according to datasheet)
    	CallTime = 40 * AP_USEC_PER_MSEC;
    }

    if (_lps2xh_type == BARO_LPS22H) {
        _dev->write_register(LPS22H_CTRL_REG1, 0x00); // turn off for config
        _dev->write_register(LPS22H_CTRL_REG1, LPS22H_CTRL_REG1_ODR_75HZ|LPS22H_CTRL_REG1_BDU|LPS22H_CTRL_REG1_EN_LPFP|LPS22H_CTRL_REG1_LPFP_CFG);
        if (_dev->bus_type() == AP_HAL::Device::BUS_TYPE_SPI) {
            _dev->write_register(LPS22H_CTRL_REG2, 0x18);  // disable i2c
        } else {
            _dev->write_register(LPS22H_CTRL_REG2, 0x10);
        }

        // request 75Hz update
        CallTime = 1000000/75;
    }

    _instance = _frontend.register_sensor();

    _dev->set_device_type(DEVTYPE_BARO_LPS2XH);
    set_bus_id(_instance, _dev->get_bus_id());
    
    _dev->get_semaphore()->give();

    _dev->register_periodic_callback(CallTime, FUNCTOR_BIND_MEMBER(&AP_Baro_LPS2XH::_timer, void));

    return true;
}

//check ID
bool AP_Baro_LPS2XH::_check_whoami(void)
{
    uint8_t whoami;
    if (!_dev->read_registers(REG_ID, &whoami, 1)) {
	   return false;
    }
    DEV_PRINTF("LPS2XH whoami 0x%02x\n", whoami);

    switch(whoami){
    case LPS22HB_WHOAMI:
        _lps2xh_type = BARO_LPS22H;
        return true;
    case LPS25HB_WHOAMI:
        _lps2xh_type = BARO_LPS25H;
        return true;
    }

    return false;
}

//  accumulate a new sensor reading
void AP_Baro_LPS2XH::_timer(void)
{
    uint8_t status;
    // use status to check if data is available
    if (!_dev->read_registers(STATUS_ADDR, &status, 1)) {
        return;
    }

    if (status & 0x02) {
        _update_temperature();
    }

    if (status & 0x01) {
        _update_pressure();
    }
}

// transfer data to the frontend
void AP_Baro_LPS2XH::update(void)
{
    if (_pressure_count == 0) {
        return;
    }

    WITH_SEMAPHORE(_sem);
    _copy_to_frontend(_instance, _pressure_sum/_pressure_count, _temperature);
    _pressure_sum = 0;
    _pressure_count = 0;
}

// calculate temperature
void AP_Baro_LPS2XH::_update_temperature(void)
{
    uint8_t pu8[2];
    if (!_dev->read_registers(TEMP_OUT_ADDR, pu8, 2)) {
        return;
    }
    int16_t Temp_Reg_s16 = (uint16_t)(pu8[1]<<8) | pu8[0];

    WITH_SEMAPHORE(_sem);

    if (_lps2xh_type == BARO_LPS25H) {
        _temperature = (Temp_Reg_s16 * (1.0/480)) + 42.5;
    }

    if (_lps2xh_type == BARO_LPS22H) {
        _temperature = Temp_Reg_s16 * 0.01;
    }
}

// calculate pressure
void AP_Baro_LPS2XH::_update_pressure(void)
{
    uint8_t pressure[3];
    if (!_dev->read_registers(PRESS_OUT_XL_ADDR, pressure, 3)) {
        return;
    }

    int32_t Pressure_Reg_s32 = ((uint32_t)pressure[2]<<16)|((uint32_t)pressure[1]<<8)|(uint32_t)pressure[0];
    int32_t Pressure_mb = Pressure_Reg_s32 * (100.0f / 4096); // scale for pa

    WITH_SEMAPHORE(_sem);
    _pressure_sum += Pressure_mb;
    _pressure_count++;
}

#endif  // AP_BARO_LPS2XH_ENABLED