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ardupilot/libraries/AP_InertialSensor/AP_InertialSensor_L3G4200D.cpp

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/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
/*
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
*/
// 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.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_LINUX
#include <AP_Math.h>
#include "AP_InertialSensor_L3G4200D.h"
#include <stdio.h>
#include <unistd.h>
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
#define ADXL345_ACCELEROMETER_ADXLREG_FIFO_STATUS 0x39
// 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(),
_accel_filter_x(800, 10),
_accel_filter_y(800, 10),
_accel_filter_z(800, 10),
_gyro_filter_x(800, 10),
_gyro_filter_y(800, 10),
_gyro_filter_z(800, 10)
{}
uint16_t AP_InertialSensor_L3G4200D::_init_sensor( Sample_rate sample_rate )
{
switch (sample_rate) {
case RATE_50HZ:
_default_filter_hz = 10;
_sample_period_usec = (1000*1000) / 50;
_gyro_samples_needed = 16;
break;
case RATE_100HZ:
_default_filter_hz = 20;
_sample_period_usec = (1000*1000) / 100;
_gyro_samples_needed = 8;
break;
case RATE_200HZ:
default:
_default_filter_hz = 20;
_sample_period_usec = (1000*1000) / 200;
_gyro_samples_needed = 4;
break;
}
// get pointer to i2c bus semaphore
AP_HAL::Semaphore* i2c_sem = hal.i2c->get_semaphore();
// take i2c bus sempahore
if (!i2c_sem->take(HAL_SEMAPHORE_BLOCK_FOREVER))
return false;
// Init the accelerometer
uint8_t data = 0;
hal.i2c->readRegister(ADXL345_ACCELEROMETER_ADDRESS, ADXL345_ACCELEROMETER_ADXLREG_DEVID, &data);
if (data != ADXL345_ACCELEROMETER_XL345_DEVID) {
hal.scheduler->panic(PSTR("AP_InertialSensor_L3G4200D: could not find ADXL345 accelerometer sensor"));
}
hal.i2c->writeRegister(ADXL345_ACCELEROMETER_ADDRESS, ADXL345_ACCELEROMETER_ADXLREG_POWER_CTL, 0x00);
hal.scheduler->delay(5);
hal.i2c->writeRegister(ADXL345_ACCELEROMETER_ADDRESS, ADXL345_ACCELEROMETER_ADXLREG_POWER_CTL, 0xff);
hal.scheduler->delay(5);
// Measure mode:
hal.i2c->writeRegister(ADXL345_ACCELEROMETER_ADDRESS, ADXL345_ACCELEROMETER_ADXLREG_POWER_CTL, 0x08);
hal.scheduler->delay(5);
// Full resolution, 8g:
// Caution, this must agree with ADXL345_ACCELEROMETER_SCALE_1G
// In full resoution mode, the scale factor need not change
hal.i2c->writeRegister(ADXL345_ACCELEROMETER_ADDRESS, ADXL345_ACCELEROMETER_ADXLREG_DATA_FORMAT, 0x08);
hal.scheduler->delay(5);
// Normal power, 800Hz Output Data Rate, 400Hz bandwidth:
hal.i2c->writeRegister(ADXL345_ACCELEROMETER_ADDRESS, ADXL345_ACCELEROMETER_ADXLREG_BW_RATE, 0x0d);
hal.scheduler->delay(5);
// enable FIFO in stream mode. This will allow us to read the accelerometers much less frequently
hal.i2c->writeRegister(ADXL345_ACCELEROMETER_ADDRESS,
ADXL345_ACCELEROMETER_ADXLREG_FIFO_CTL,
ADXL345_ACCELEROMETER_ADXLREG_FIFO_CTL_STREAM);
// Init the Gyro
// Expect to read the right 'WHO_AM_I' value
hal.i2c->readRegister(L3G4200D_I2C_ADDRESS, L3G4200D_REG_WHO_AM_I, &data);
if (data != L3G4200D_REG_WHO_AM_I_VALUE)
hal.scheduler->panic(PSTR("AP_InertialSensor_L3G4200D: could not find L3G4200D gyro sensor"));
// setup for 800Hz sampling with 110Hz filter
hal.i2c->writeRegister(L3G4200D_I2C_ADDRESS,
L3G4200D_REG_CTRL_REG1,
L3G4200D_REG_CTRL_REG1_DRBW_800_110 |
L3G4200D_REG_CTRL_REG1_PD |
L3G4200D_REG_CTRL_REG1_XYZ_ENABLE);
hal.scheduler->delay(1);
hal.i2c->writeRegister(L3G4200D_I2C_ADDRESS,
L3G4200D_REG_CTRL_REG1,
L3G4200D_REG_CTRL_REG1_DRBW_800_110 |
L3G4200D_REG_CTRL_REG1_PD |
L3G4200D_REG_CTRL_REG1_XYZ_ENABLE);
hal.scheduler->delay(1);
hal.i2c->writeRegister(L3G4200D_I2C_ADDRESS,
L3G4200D_REG_CTRL_REG1,
L3G4200D_REG_CTRL_REG1_DRBW_800_110 |
L3G4200D_REG_CTRL_REG1_PD |
L3G4200D_REG_CTRL_REG1_XYZ_ENABLE);
hal.scheduler->delay(1);
// setup for 2000 degrees/sec full range
hal.i2c->writeRegister(L3G4200D_I2C_ADDRESS,
L3G4200D_REG_CTRL_REG4,
L3G4200D_REG_CTRL_REG4_FS_2000);
hal.scheduler->delay(1);
// enable FIFO
hal.i2c->writeRegister(L3G4200D_I2C_ADDRESS,
L3G4200D_REG_CTRL_REG5,
L3G4200D_REG_CTRL_REG5_FIFO_EN);
hal.scheduler->delay(1);
// enable FIFO in stream mode. This will allow us to read the gyros much less frequently
hal.i2c->writeRegister(L3G4200D_I2C_ADDRESS,
L3G4200D_REG_FIFO_CTL,
L3G4200D_REG_FIFO_CTL_STREAM);
hal.scheduler->delay(1);
// Set up the filter desired
_set_filter_frequency(_mpu6000_filter);
// give back i2c semaphore
i2c_sem->give();
// start the timer process to read samples
hal.scheduler->register_timer_process(AP_HAL_MEMBERPROC(&AP_InertialSensor_L3G4200D::_accumulate));
return AP_PRODUCT_ID_L3G4200D;
}
/*
set the filter frequency
*/
void AP_InertialSensor_L3G4200D::_set_filter_frequency(uint8_t filter_hz)
{
if (filter_hz == 0)
filter_hz = _default_filter_hz;
_accel_filter_x.set_cutoff_frequency(800, filter_hz);
_accel_filter_y.set_cutoff_frequency(800, filter_hz);
_accel_filter_z.set_cutoff_frequency(800, filter_hz);
_gyro_filter_x.set_cutoff_frequency(800, filter_hz);
_gyro_filter_y.set_cutoff_frequency(800, filter_hz);
_gyro_filter_z.set_cutoff_frequency(800, filter_hz);
}
/*================ AP_INERTIALSENSOR PUBLIC INTERFACE ==================== */
bool AP_InertialSensor_L3G4200D::update(void)
{
if (!wait_for_sample(1000)) {
return false;
}
Vector3f accel_scale = _accel_scale.get();
_previous_accel = _accel;
hal.scheduler->suspend_timer_procs();
_accel = _accel_filtered;
_gyro = _gyro_filtered;
_gyro_samples_available = 0;
hal.scheduler->resume_timer_procs();
// add offsets and rotation
_accel.rotate(_board_orientation);
// Adjust for chip scaling to get m/s/s
_accel *= ADXL345_ACCELEROMETER_SCALE_M_S;
// Now the calibration scale factor
_accel.x *= accel_scale.x;
_accel.y *= accel_scale.y;
_accel.z *= accel_scale.z;
_accel -= _accel_offset;
_gyro.rotate(_board_orientation);
// Adjust for chip scaling to get radians/sec
_gyro *= L3G4200D_GYRO_SCALE_R_S;
_gyro -= _gyro_offset;
if (_last_filter_hz != _mpu6000_filter) {
_set_filter_frequency(_mpu6000_filter);
_last_filter_hz = _mpu6000_filter;
}
return true;
}
float AP_InertialSensor_L3G4200D::get_delta_time(void)
{
return _sample_period_usec * 1.0e-6f;
}
float AP_InertialSensor_L3G4200D::get_gyro_drift_rate(void)
{
// 0.5 degrees/second/minute (a guess)
return ToRad(0.5/60);
}
// Accumulate values from accels and gyros
void AP_InertialSensor_L3G4200D::_accumulate(void)
{
// get pointer to i2c bus semaphore
AP_HAL::Semaphore* i2c_sem = hal.i2c->get_semaphore();
// take i2c bus sempahore
if (!i2c_sem->take_nonblocking())
return;
// Read accelerometer FIFO to find out how many samples are available
uint8_t num_samples_available;
uint8_t fifo_status = 0;
hal.i2c->readRegister(ADXL345_ACCELEROMETER_ADDRESS,
ADXL345_ACCELEROMETER_ADXLREG_FIFO_STATUS,
&fifo_status);
num_samples_available = fifo_status & 0x3F;
// read the samples and apply the filter
for (uint8_t i=0; i<num_samples_available; i++) {
int16_t buffer[3];
if (hal.i2c->readRegisters(ADXL345_ACCELEROMETER_ADDRESS,
ADXL345_ACCELEROMETER_ADXLREG_DATAX0, sizeof(buffer), (uint8_t *)buffer) == 0) {
_accel_filtered = Vector3f(_accel_filter_x.apply(buffer[0]),
_accel_filter_y.apply(-buffer[1]),
_accel_filter_z.apply(-buffer[2]));
}
}
// Read gyro FIFO status
fifo_status = 0;
hal.i2c->readRegister(L3G4200D_I2C_ADDRESS,
L3G4200D_REG_FIFO_SRC,
&fifo_status);
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;
}
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 (hal.i2c->readRegisters(L3G4200D_I2C_ADDRESS, L3G4200D_REG_XL | L3G4200D_REG_AUTO_INCREMENT,
sizeof(buffer), (uint8_t *)&buffer[0][0]) == 0) {
for (uint8_t i=0; i<num_samples_available; i++) {
_gyro_filtered = Vector3f(_gyro_filter_x.apply(buffer[i][0]),
_gyro_filter_y.apply(-buffer[i][1]),
_gyro_filter_z.apply(-buffer[i][2]));
_gyro_samples_available++;
}
}
}
// give back i2c semaphore
i2c_sem->give();
}
bool AP_InertialSensor_L3G4200D::sample_available(void)
{
return (_gyro_samples_available >= _gyro_samples_needed);
}
bool AP_InertialSensor_L3G4200D::wait_for_sample(uint16_t timeout_ms)
{
if (sample_available()) {
_last_sample_time = hal.scheduler->micros();
return true;
}
uint32_t start = hal.scheduler->millis();
while ((hal.scheduler->millis() - start) < timeout_ms) {
hal.scheduler->delay_microseconds(100);
_accumulate();
if (sample_available()) {
_last_sample_time = hal.scheduler->micros();
return true;
}
}
return false;
}
#endif // CONFIG_HAL_BOARD
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