ardupilot/libraries/AP_InertialSensor/AP_InertialSensor_L3G4200D.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/>.
 */
/*
  This is an INS driver for the combination L3G4200D gyro and ADXL345 accelerometer.
  This combination is available as a cheap 10DOF sensor on ebay

  This sensor driver is an example only - it should not be used in any
  serious autopilot as the latencies on I2C prevent good timing at
  high sample rates. It is useful when doing an initial port of
  ardupilot to a board where only I2C is available, and a cheap sensor
  can be used.

Datasheets:
  ADXL345 Accelerometer http://www.analog.com/static/imported-files/data_sheets/ADXL345.pdf
  L3G4200D gyro http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00265057.pdf
*/

#include <AP_HAL/AP_HAL.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_LINUX

#include "AP_InertialSensor_L3G4200D.h"

#include <inttypes.h>
#include <utility>



const extern AP_HAL::HAL& hal;

///////
/// Accelerometer ADXL345 register definitions
#define ADXL345_ACCELEROMETER_ADDRESS                  0x53
#define ADXL345_ACCELEROMETER_XL345_DEVID              0xe5
#define ADXL345_ACCELEROMETER_ADXLREG_BW_RATE          0x2c
#define ADXL345_ACCELEROMETER_ADXLREG_POWER_CTL        0x2d
#define ADXL345_ACCELEROMETER_ADXLREG_DATA_FORMAT      0x31
#define ADXL345_ACCELEROMETER_ADXLREG_DEVID            0x00
#define ADXL345_ACCELEROMETER_ADXLREG_DATAX0           0x32
#define ADXL345_ACCELEROMETER_ADXLREG_FIFO_CTL         0x38
#define ADXL345_ACCELEROMETER_ADXLREG_FIFO_CTL_STREAM  0x9F // 32 sample before triggering
#define ADXL345_ACCELEROMETER_ADXLREG_FIFO_STATUS      0x39

#define ADXL345_ACCELEROMETER_BW_RATE_0_10HZ                       0x00
#define ADXL345_ACCELEROMETER_BW_RATE_0_20HZ                       0x01
#define ADXL345_ACCELEROMETER_BW_RATE_0_39HZ                       0x02
#define ADXL345_ACCELEROMETER_BW_RATE_0_78HZ                       0x03
#define ADXL345_ACCELEROMETER_BW_RATE_1_56HZ                       0x04
#define ADXL345_ACCELEROMETER_BW_RATE_3_13HZ                       0x05
#define ADXL345_ACCELEROMETER_BW_RATE_6_25HZ                       0x06
#define ADXL345_ACCELEROMETER_BW_RATE_12_5HZ                       0x07
#define ADXL345_ACCELEROMETER_BW_RATE_25HZ                         0x08
#define ADXL345_ACCELEROMETER_BW_RATE_50HZ                         0x09
#define ADXL345_ACCELEROMETER_BW_RATE_100HZ                        0x0A 
#define ADXL345_ACCELEROMETER_BW_RATE_200HZ                        0x0B
#define ADXL345_ACCELEROMETER_BW_RATE_400HZ                        0x0C
#define ADXL345_ACCELEROMETER_BW_RATE_800HZ                        0x0D
#define ADXL345_ACCELEROMETER_BW_RATE_1600HZ                       0x0E
#define ADXL345_ACCELEROMETER_BW_RATE_3200HZ                       0x0F



#define ADXL345_ACCELEROMETER_ENABLE                   0x08

#define ADXL345_ACCELEROMETER_MEASURE_MODE             0x08

#define ADXL345_ACCELEROMETER_RANGE_2G                 0x00
#define ADXL345_ACCELEROMETER_RANGE_4G                 0x01
#define ADXL345_ACCELEROMETER_RANGE_8G                 0x02
#define ADXL345_ACCELEROMETER_RANGE_16G                0x03


// ADXL345 accelerometer scaling
// Result will be scaled to 1m/s/s
// ADXL345 in Full resolution mode (any g scaling) is 256 counts/g, so scale by 9.81/256 = 0.038320312
#define ADXL345_ACCELEROMETER_SCALE_M_S    (GRAVITY_MSS / 256.0f)

/// Gyro ITG3205 register definitions
#define L3G4200D_I2C_ADDRESS                            0x69

#define L3G4200D_REG_WHO_AM_I                           0x0f
#define L3G4200D_REG_WHO_AM_I_VALUE                     0xd3

#define L3G4200D_REG_CTRL_REG1                          0x20
#define L3G4200D_REG_CTRL_REG1_DRBW_800_110             0xf0
#define L3G4200D_REG_CTRL_REG1_PD                       0x08
#define L3G4200D_REG_CTRL_REG1_XYZ_ENABLE               0x07

#define L3G4200D_REG_CTRL_REG4                          0x23
#define L3G4200D_REG_CTRL_REG4_FS_2000                  0x30

#define L3G4200D_REG_CTRL_REG5                          0x24
#define L3G4200D_REG_CTRL_REG5_FIFO_EN                  0x40
#define L3G4200D_REG_FIFO_CTL                           0x2e
#define L3G4200D_REG_FIFO_CTL_STREAM                    0x40

#define L3G4200D_REG_FIFO_SRC                           0x2f
#define L3G4200D_REG_FIFO_SRC_ENTRIES_MASK              0x1f
#define L3G4200D_REG_FIFO_SRC_EMPTY                     0x20
#define L3G4200D_REG_FIFO_SRC_OVERRUN                   0x40

#define L3G4200D_REG_XL                                 0x28

// this bit is ORd into the register to enable auto-increment mode
#define L3G4200D_REG_AUTO_INCREMENT		                0x80

// L3G4200D Gyroscope scaling
// running at 2000 DPS full range, 16 bit signed data, datasheet
// specifies 70 mdps per bit
#define L3G4200D_GYRO_SCALE_R_S (DEG_TO_RAD * 70.0f * 0.001f)

// constructor
AP_InertialSensor_L3G4200D::AP_InertialSensor_L3G4200D(AP_InertialSensor &imu,
                                                    AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev_gyro,
                                                    AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev_accel)
    : AP_InertialSensor_Backend(imu)
    , _dev_gyro(std::move(dev_gyro))
    , _dev_accel(std::move(dev_accel))
{
}


AP_InertialSensor_L3G4200D::~AP_InertialSensor_L3G4200D()
{
}

/*
  detect the sensor
 */
AP_InertialSensor_Backend *AP_InertialSensor_L3G4200D::probe(AP_InertialSensor &imu,
                                                            AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev_gyro,
                                                            AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev_accel)
{
    if ((!dev_accel) || (!dev_gyro)){
        return nullptr;
    }
    AP_InertialSensor_L3G4200D *sensor
        = new AP_InertialSensor_L3G4200D(imu, std::move(dev_gyro), std::move(dev_accel));
    if (!sensor || !sensor->_init_sensor()) {
        delete sensor;
        return nullptr;
    }

    return sensor;
}



bool AP_InertialSensor_L3G4200D::_accel_init()
{
    _dev_accel->get_semaphore()->take_blocking();

    // Init the accelerometer
    uint8_t data = 0;
    _dev_accel->read_registers(ADXL345_ACCELEROMETER_ADXLREG_DEVID, &data, 1);
    if (data != ADXL345_ACCELEROMETER_XL345_DEVID) {
        AP_HAL::panic("AP_InertialSensor_L3G4200D: could not find ADXL345 accelerometer sensor");
    }
    // Full resolution, 8g:
    // Caution, this must agree with ADXL345_ACCELEROMETER_SCALE_1G
    // In full resoution mode, the scale factor need not change
    _dev_accel->write_register(ADXL345_ACCELEROMETER_ADXLREG_DATA_FORMAT, ADXL345_ACCELEROMETER_RANGE_2G);
    hal.scheduler->delay(5);

    // Normal power, 800Hz Output Data Rate, 400Hz bandwidth:
    _dev_accel->write_register(ADXL345_ACCELEROMETER_ADXLREG_BW_RATE, ADXL345_ACCELEROMETER_BW_RATE_400HZ);
    hal.scheduler->delay(5);

    // enable FIFO in stream mode. This will allow us to read the gyros much less frequently
    _dev_accel->write_register(ADXL345_ACCELEROMETER_ADXLREG_FIFO_CTL,
                                ADXL345_ACCELEROMETER_ADXLREG_FIFO_CTL_STREAM);
    hal.scheduler->delay(5);

    // Measure mode:
    _dev_accel->write_register(ADXL345_ACCELEROMETER_ADXLREG_POWER_CTL, 
                                ADXL345_ACCELEROMETER_MEASURE_MODE);
    hal.scheduler->delay(5);

    // Set up the filter desired
    _set_filter_frequency(_accel_filter_cutoff());

    _dev_accel->get_semaphore()->give();
    
    return true;
}

bool AP_InertialSensor_L3G4200D::_gyro_init()
{
    uint8_t data = 0;
    // Init the Gyro

    _dev_gyro->get_semaphore()->take_blocking();

    _dev_gyro->read_registers(L3G4200D_REG_WHO_AM_I, &data, 1);
    if (data != L3G4200D_REG_WHO_AM_I_VALUE) {
        AP_HAL::panic("AP_InertialSensor_L3G4200D: could not find L3G4200D gyro sensor");
    }
    
    // setup for 800Hz sampling with 110Hz filter 
    _dev_gyro->write_register(L3G4200D_REG_CTRL_REG1,           // CTRL_REG1   400Hz ODR, 20hz filter, run!
                         L3G4200D_REG_CTRL_REG1_DRBW_800_110 |
                         L3G4200D_REG_CTRL_REG1_PD |
                         L3G4200D_REG_CTRL_REG1_XYZ_ENABLE);
    hal.scheduler->delay(5);


    // setup for 2000 degrees/sec full range
    _dev_gyro->write_register(L3G4200D_REG_CTRL_REG4,
                         L3G4200D_REG_CTRL_REG4_FS_2000);
    hal.scheduler->delay(5);

    // enable FIFO
    _dev_gyro->write_register(L3G4200D_REG_CTRL_REG5,
                         L3G4200D_REG_CTRL_REG5_FIFO_EN);
    hal.scheduler->delay(5);

    // enable FIFO in stream mode. This will allow us to read the gyros much less frequently
    _dev_gyro->write_register(L3G4200D_REG_FIFO_CTL,
                         L3G4200D_REG_FIFO_CTL_STREAM);
    hal.scheduler->delay(5);

    _dev_gyro->get_semaphore()->give();

    return true;
}

bool AP_InertialSensor_L3G4200D::_init_sensor(void)
{
    
    _accel_init();

    _gyro_init();

    return true;
}

/*
  startup the sensor
 */
void AP_InertialSensor_L3G4200D::start(void)
{
    if (!_imu.register_gyro(_gyro_instance, 800, _dev_gyro->get_bus_id_devtype(DEVTYPE_L3G4200D)) ||
        !_imu.register_accel(_accel_instance, 800, _dev_accel->get_bus_id_devtype(DEVTYPE_L3G4200D))) {
        return;
    }

    // start the timer process to read samples
    _dev_accel->register_periodic_callback(1250, FUNCTOR_BIND_MEMBER(&AP_InertialSensor_L3G4200D::_accumulate_accel, void));
    _dev_gyro->register_periodic_callback(1250, FUNCTOR_BIND_MEMBER(&AP_InertialSensor_L3G4200D::_accumulate_gyro, void));
}


/*
  set the filter frequency
 */
void AP_InertialSensor_L3G4200D::_set_filter_frequency(uint8_t filter_hz)
{
    _accel_filter.set_cutoff_frequency(800, filter_hz);
    _gyro_filter.set_cutoff_frequency(800, filter_hz);
}


/*
  copy filtered data to the frontend
 */
bool AP_InertialSensor_L3G4200D::update(void)
{
    update_gyro(_gyro_instance);
    update_accel(_accel_instance);

    return true;
}

// Accumulate values from accels and gyros
void AP_InertialSensor_L3G4200D::_accumulate_gyro (void)
{
    uint8_t num_samples_available;
    uint8_t fifo_status = 0;

    // Read gyro FIFO status
    fifo_status = 0;
    _dev_gyro->read_registers(L3G4200D_REG_FIFO_SRC, &fifo_status, 1);
    if (fifo_status & L3G4200D_REG_FIFO_SRC_OVERRUN) {
        // FIFO is full
        num_samples_available = 32;
    } else if (fifo_status & L3G4200D_REG_FIFO_SRC_EMPTY) {
        // FIFO is empty
        num_samples_available = 0;
    } else {
        // FIFO is partly full
        num_samples_available = fifo_status & L3G4200D_REG_FIFO_SRC_ENTRIES_MASK;
    }

    // read the samples and apply the filter
    if (num_samples_available > 0) {
        // read all the entries in one go, using AUTO_INCREMENT. This saves a lot of time on I2C setup
        int16_t buffer[num_samples_available][3];
        if (_dev_gyro->read_registers(L3G4200D_REG_XL | L3G4200D_REG_AUTO_INCREMENT,
                                  (uint8_t *)&buffer, sizeof(buffer))) {
            for (uint8_t i=0; i < num_samples_available; i++) {
                Vector3f gyro = Vector3f(buffer[i][0], -buffer[i][1], -buffer[i][2]);
                // Adjust for chip scaling to get radians/sec
                //hal.console->printf("gyro %f \r\n",gyro.x); 
                gyro *= L3G4200D_GYRO_SCALE_R_S;
                _rotate_and_correct_gyro(_gyro_instance, gyro);
                _notify_new_gyro_raw_sample(_gyro_instance, gyro);
            }
        }
    }
}

void AP_InertialSensor_L3G4200D::_accumulate_accel (void)
{
    uint8_t num_samples_available;
    uint8_t fifo_status = 0;

    // Read accelerometer FIFO to find out how many samples are available
    _dev_accel->read_registers(ADXL345_ACCELEROMETER_ADXLREG_FIFO_STATUS,
                         &fifo_status, 1);
    num_samples_available = fifo_status & 0x3F;

    // read the samples and apply the filter
    if (num_samples_available > 0) {
        int16_t buffer[num_samples_available][3];
        for (uint8_t i=0; i<num_samples_available; i++) 
        {
            if (_dev_accel->read_registers(ADXL345_ACCELEROMETER_ADXLREG_DATAX0,
                                           (uint8_t *)buffer[i], sizeof(buffer[0])))
            {
                Vector3f accel = Vector3f(buffer[i][0], -buffer[i][1], -buffer[i][2]);
                // Adjust for chip scaling to get m/s/s
                accel *= ADXL345_ACCELEROMETER_SCALE_M_S;
                _rotate_and_correct_accel(_accel_instance, accel);
                _notify_new_accel_raw_sample(_accel_instance, accel);
            }
        }
    } 
}

#endif