AP_Baro_BMP581.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_BMP581.h"

#if AP_BARO_BMP581_ENABLED

#include <AP_Math/AP_Math.h>

extern const AP_HAL::HAL &hal;

#define BMP581_ID                     0x50

#define BMP581_REG_CHIP_ID            0x01
#define BMP581_REG_REV_ID             0x02
#define BMP581_REG_CHIP_STATUS        0x11
#define BMP581_REG_DRIVE_CONFIG       0x13
#define BMP581_REG_INT_CONFIG         0x14
#define BMP581_REG_INT_SOURCE         0x15
#define BMP581_REG_FIFO_CONFIG        0x16
#define BMP581_REG_FIFO_COUNT         0x17
#define BMP581_REG_FIFO_SEL           0x18
#define BMP581_REG_TEMP_DATA_XLSB     0x1D
#define BMP581_REG_TEMP_DATA_LSB      0x1E
#define BMP581_REG_TEMP_DATA_MSB      0x1F
#define BMP581_REG_PRESS_DATA_XLSB    0x20
#define BMP581_REG_PRESS_DATA_LSB     0x21
#define BMP581_REG_PRESS_DATA_MSB     0x22
#define BMP581_REG_INT_STATUS         0x27
#define BMP581_REG_STATUS             0x28
#define BMP581_REG_FIFO_DATA          0x29
#define BMP581_REG_NVM_ADDR           0x2B
#define BMP581_REG_NVM_DATA_LSB       0x2C
#define BMP581_REG_NVM_DATA_MSB       0x2D
#define BMP581_REG_DSP_CONFIG         0x30
#define BMP581_REG_DSP_IIR            0x31
#define BMP581_REG_OOR_THR_P_LSB      0x32
#define BMP581_REG_OOR_THR_P_MSB      0x33
#define BMP581_REG_OOR_RANGE          0x34
#define BMP581_REG_OOR_CONFIG         0x35
#define BMP581_REG_OSR_CONFIG         0x36
#define BMP581_REG_ODR_CONFIG         0x37
#define BMP581_REG_OSR_EFF            0x38
#define BMP581_REG_CMD                0x7E

AP_Baro_BMP581::AP_Baro_BMP581(AP_Baro &baro, AP_HAL::Device &dev)
    : AP_Baro_Backend(baro)
    , _dev(&dev)
{
}

AP_Baro_Backend *AP_Baro_BMP581::probe(AP_Baro &baro, AP_HAL::Device &dev)
{
    AP_Baro_BMP581 *sensor = NEW_NOTHROW AP_Baro_BMP581(baro, dev);
    if (!sensor || !sensor->init()) {
        delete sensor;
        return nullptr;
    }
    return sensor;
}

bool AP_Baro_BMP581::init()
{
    if (!_dev) {
        return false;
    }

    WITH_SEMAPHORE(_dev->get_semaphore());

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

    uint8_t whoami;

    // setup to allow reads on SPI
    if (_dev->bus_type() == AP_HAL::Device::BUS_TYPE_SPI) {
        _dev->set_read_flag(0x80);

        if (!_dev->read_registers(BMP581_REG_CHIP_ID, &whoami, 1)) {
            return false;
        }
    }

    if (!_dev->read_registers(BMP581_REG_CHIP_ID, &whoami, 1)) {
        return false;
    }

    switch (whoami) {
    case BMP581_ID:
        _dev->set_device_type(DEVTYPE_BARO_BMP581);
        break;
    default:
        return false;
    }

    uint8_t status;
    if (!_dev->read_registers(BMP581_REG_STATUS, &status, 1)) {
        return false;
    }

    if ((status & 0b10) == 0 || (status & 0b100)) {
        return false;
    }

    uint8_t int_status;
    if (!_dev->read_registers(BMP581_REG_INT_STATUS, &int_status, 1)) {
        return false;
    }

    if ((int_status & 0x10) == 0) {
        return false;
    }

    _dev->setup_checked_registers(4);

    // Standby mode
    _dev->write_register(BMP581_REG_ODR_CONFIG, 0, true);

    // Press EN | osr_p 64X | osr_t 4X
    _dev->write_register(BMP581_REG_OSR_CONFIG, 0b01110010, true);

    // ORD 50Hz | Normal Mode
    _dev->write_register(BMP581_REG_ODR_CONFIG, 0b0111101, true);

    instance = _frontend.register_sensor();

    set_bus_id(instance, _dev->get_bus_id());

    // request 50Hz update
    _dev->register_periodic_callback(20 * AP_USEC_PER_MSEC, FUNCTOR_BIND_MEMBER(&AP_Baro_BMP581::timer, void));

    return true;
}

// acumulate a new sensor reading
void AP_Baro_BMP581::timer(void)
{
    uint8_t buf[6];

    if (!_dev->read_registers(BMP581_REG_TEMP_DATA_XLSB, buf, sizeof(buf))) {
        return;
    }

    WITH_SEMAPHORE(_sem);

    if (buf[0] != 0x7f || buf[1] != 0x7f || buf[2] != 0x7f) {
        // we have temperature data
        temperature = (float)((int32_t)(((uint32_t)buf[2] << 24) | ((uint32_t)buf[1] << 16) | ((uint32_t)buf[0] << 8)) >> 8) * (1.0f / 65536.0f);
    }

    if (buf[3] != 0x7f || buf[4] != 0x7f || buf[5] != 0x7f) {
        // we have pressure data
        pressure_sum += (float)(((uint32_t)buf[5] << 16) | ((uint32_t)buf[4] << 8) | (uint32_t)buf[3]) * (1.0f / 64.0f);
        pressure_count++;
    }

    _dev->check_next_register();
}

// transfer data to the frontend
void AP_Baro_BMP581::update(void)
{
    WITH_SEMAPHORE(_sem);

    if (pressure_count == 0) {
        return;
    }

    _copy_to_frontend(instance,
                      pressure_sum/pressure_count,
                      temperature);

    pressure_sum = 0;
    pressure_count = 0;
}

#endif  // AP_BARO_BMP581_ENABLED