void
MPU9250::write_reg(unsigned reg, uint8_t value)
{
// general register transfer at low clock speed
if (_whoami == ICM_WHOAMI_20948) {
select_register_bank(REG_BANK(reg));
_interface->write(MPU9250_LOW_SPEED_OP(REG_ADDRESS(reg)), &value, 1);
} else {
_interface->write(MPU9250_LOW_SPEED_OP(reg), &value, 1);
}
}
uint8_t
MPU9250::read_reg(unsigned reg, uint32_t speed)
{
uint8_t buf;
if (_whoami == ICM_WHOAMI_20948) {
select_register_bank(REG_BANK(reg));
_interface->read(MPU9250_SET_SPEED(REG_ADDRESS(reg), speed), &buf, 1);
} else {
_interface->read(MPU9250_SET_SPEED(REG_ADDRESS(reg), speed), &buf, 1);
}
return buf;
}
uint16_t
MPU9250::read_reg16(unsigned reg)
{
uint8_t buf[2];
// general register transfer at low clock speed
if (_whoami == ICM_WHOAMI_20948) {
select_register_bank(REG_BANK(reg));
_interface->read(MPU9250_LOW_SPEED_OP(REG_ADDRESS(reg)), &buf, arraySize(buf));
} else {
_interface->read(MPU9250_LOW_SPEED_OP(reg), &buf, arraySize(buf));
}
return (uint16_t)(buf[0] << 8) | buf[1];
}
uint8_t
MPU9250::read_reg_range(unsigned start_reg, uint32_t speed, uint8_t *buf, uint16_t count)
{
uint8_t ret;
if (buf == NULL) { return PX4_ERROR; }
if (_whoami == ICM_WHOAMI_20948) {
select_register_bank(REG_BANK(start_reg));
ret = _interface->read(MPU9250_SET_SPEED(REG_ADDRESS(start_reg), speed), buf, count);
} else {
ret = _interface->read(MPU9250_SET_SPEED(REG_ADDRESS(start_reg), speed), buf, count);
}
return ret;
}
int
MPU9250::probe()
{
int ret = PX4_ERROR;
// Try first for mpu9250/6500
_whoami = read_reg(MPUREG_WHOAMI);
// If it's not an MPU it must be an ICM
if ((_whoami != MPU_WHOAMI_9250) && (_whoami != MPU_WHOAMI_6500)) {
// Make sure selected register bank is bank 0 (which contains WHOAMI)
select_register_bank(REG_BANK(ICMREG_20948_WHOAMI));
_whoami = read_reg(ICMREG_20948_WHOAMI);
}
if (_whoami == MPU_WHOAMI_9250 || _whoami == MPU_WHOAMI_6500) {
_num_checked_registers = MPU9250_NUM_CHECKED_REGISTERS;
_checked_registers = _mpu9250_checked_registers;
memset(_checked_values, 0, MPU9250_NUM_CHECKED_REGISTERS);
memset(_checked_bad, 0, MPU9250_NUM_CHECKED_REGISTERS);
ret = PX4_OK;
} else if (_whoami == ICM_WHOAMI_20948) {
_num_checked_registers = ICM20948_NUM_CHECKED_REGISTERS;
_checked_registers = _icm20948_checked_registers;
memset(_checked_values, 0, ICM20948_NUM_CHECKED_REGISTERS);
memset(_checked_bad, 0, ICM20948_NUM_CHECKED_REGISTERS);
ret = PX4_OK;
}
_checked_values[0] = _whoami;
_checked_bad[0] = _whoami;
if (ret != PX4_OK) {
PX4_DEBUG("unexpected whoami 0x%02x", _whoami);
}
return ret;
}
int MPU9250::reset_mpu()
{
uint8_t retries;
switch (_whoami) {
case MPU_WHOAMI_9250:
case MPU_WHOAMI_6500:
write_reg(MPUREG_PWR_MGMT_1, BIT_H_RESET);
write_checked_reg(MPUREG_PWR_MGMT_1, MPU_CLK_SEL_AUTO);
write_checked_reg(MPUREG_PWR_MGMT_2, 0);
usleep(1000);
break;
}
// Enable I2C bus or Disable I2C bus (recommended on data sheet)
write_checked_reg(MPUREG_USER_CTRL, is_i2c() ? 0 : BIT_I2C_IF_DIS);
// SAMPLE RATE
_set_sample_rate(_sample_rate);
_set_dlpf_filter(MPU9250_DEFAULT_ONCHIP_FILTER_FREQ);
// Gyro scale 2000 deg/s ()
switch (_whoami) {
case MPU_WHOAMI_9250:
case MPU_WHOAMI_6500:
write_checked_reg(MPUREG_GYRO_CONFIG, BITS_FS_2000DPS);
break;
}
// correct gyro scale factors
// scale to rad/s in SI units
// 2000 deg/s = (2000/180)*PI = 34.906585 rad/s
// scaling factor:
// 1/(2^15)*(2000/180)*PI
_gyro_range_scale = (0.0174532 / 16.4);//1.0f / (32768.0f * (2000.0f / 180.0f) * M_PI_F);
_gyro_range_rad_s = (2000.0f / 180.0f) * M_PI_F;
set_accel_range(ACCEL_RANGE_G);
// INT CFG => Interrupt on Data Ready
write_checked_reg(MPUREG_INT_ENABLE, BIT_RAW_RDY_EN); // INT: Raw data ready
#ifdef USE_I2C
bool bypass = !_mag->is_passthrough();
#else
bool bypass = false;
#endif
/* INT: Clear on any read.
* If this instance is for a device is on I2C bus the Mag will have an i2c interface
* that it will use to access the either: a) the internal mag device on the internal I2C bus
* or b) it could be used to access a downstream I2C devices connected to the chip on
* it's AUX_{ASD|SCL} pins. In either case we need to disconnect (bypass) the internal master
* controller that chip provides as a SPI to I2C bridge.
* so bypass is true if the mag has an i2c non null interfaces.
*/
write_checked_reg(MPUREG_INT_PIN_CFG, BIT_INT_ANYRD_2CLEAR | (bypass ? BIT_INT_BYPASS_EN : 0));
write_checked_reg(MPUREG_ACCEL_CONFIG2, BITS_ACCEL_CONFIG2_41HZ);
retries = 3;
bool all_ok = false;
while (!all_ok && retries--) {
// Assume all checked values are as expected
all_ok = true;
uint8_t reg;
uint8_t bankcheck = 0;
for (uint8_t i = 0; i < _num_checked_registers; i++) {
if ((reg = read_reg(_checked_registers[i])) != _checked_values[i]) {
write_reg(_checked_registers[i], _checked_values[i]);
PX4_ERR("Reg %d is:%d s/b:%d Tries:%d - bank s/b %d, is %d", _checked_registers[i], reg, _checked_values[i], retries,
REG_BANK(_checked_registers[i]), bankcheck);
all_ok = false;
}
}
}
return all_ok ? OK : -EIO;
}
void
MPU9250::measure()
{
if (hrt_absolute_time() < _reset_wait) {
// we're waiting for a reset to complete
return;
}
struct MPUReport mpu_report;
struct ICMReport icm_report;
struct Report {
int16_t accel_x;
int16_t accel_y;
int16_t accel_z;
int16_t temp;
int16_t gyro_x;
int16_t gyro_y;
int16_t gyro_z;
} report;
/* start measuring */
perf_begin(_sample_perf);
/*
* Fetch the full set of measurements from the MPU9250 in one pass
*/
if ((!_magnetometer_only || _mag->is_passthrough()) && _register_wait == 0) {
if (_whoami == MPU_WHOAMI_9250 || _whoami == MPU_WHOAMI_6500) {
if (OK != read_reg_range(MPUREG_INT_STATUS, MPU9250_HIGH_BUS_SPEED, (uint8_t *)&mpu_report, sizeof(mpu_report))) {
perf_end(_sample_perf);
return;
}
} else { // ICM20948
select_register_bank(REG_BANK(ICMREG_20948_ACCEL_XOUT_H));
if (OK != read_reg_range(ICMREG_20948_ACCEL_XOUT_H, MPU9250_HIGH_BUS_SPEED, (uint8_t *)&icm_report,
sizeof(icm_report))) {
perf_end(_sample_perf);
return;
}
}
check_registers();
if (check_duplicate(MPU_OR_ICM(&mpu_report.accel_x[0], &icm_report.accel_x[0]))) {
return;
}
}
/*
* In case of a mag passthrough read, hand the magnetometer data over to _mag. Else,
* try to read a magnetometer report.
*/
# ifdef USE_I2C
if (_mag->is_passthrough()) {
# endif
_mag->_measure(mpu_report.mag);
# ifdef USE_I2C
} else {
_mag->measure();
}
# endif
/*
* Continue evaluating gyro and accelerometer results
*/
if (!_magnetometer_only && _register_wait == 0) {
/*
* Convert from big to little endian
*/
if (_whoami == ICM_WHOAMI_20948) {
report.accel_x = int16_t_from_bytes(icm_report.accel_x);
report.accel_y = int16_t_from_bytes(icm_report.accel_y);
report.accel_z = int16_t_from_bytes(icm_report.accel_z);
report.temp = int16_t_from_bytes(icm_report.temp);
report.gyro_x = int16_t_from_bytes(icm_report.gyro_x);
report.gyro_y = int16_t_from_bytes(icm_report.gyro_y);
report.gyro_z = int16_t_from_bytes(icm_report.gyro_z);
} else { // MPU9250/MPU6500
report.accel_x = int16_t_from_bytes(mpu_report.accel_x);
report.accel_y = int16_t_from_bytes(mpu_report.accel_y);
report.accel_z = int16_t_from_bytes(mpu_report.accel_z);
report.temp = int16_t_from_bytes(mpu_report.temp);
report.gyro_x = int16_t_from_bytes(mpu_report.gyro_x);
report.gyro_y = int16_t_from_bytes(mpu_report.gyro_y);
report.gyro_z = int16_t_from_bytes(mpu_report.gyro_z);
}
if (check_null_data((uint16_t *)&report, sizeof(report) / 2)) {
return;
}
}
if (_register_wait != 0) {
/*
* We are waiting for some good transfers before using the sensor again.
* We still increment _good_transfers, but don't return any data yet.
*
*/
_register_wait--;
return;
}
/*
* Get sensor temperature
*/
_last_temperature = (report.temp) / 333.87f + 21.0f;
/*
* Convert and publish accelerometer and gyrometer data.
*/
if (!_magnetometer_only) {
/*
* Keeping the axes as they are for ICM20948 so orientation will match the actual chip orientation
*/
if (_whoami != ICM_WHOAMI_20948) {
/*
* Swap axes and negate y
*/
int16_t accel_xt = report.accel_y;
int16_t accel_yt = ((report.accel_x == -32768) ? 32767 : -report.accel_x);
int16_t gyro_xt = report.gyro_y;
int16_t gyro_yt = ((report.gyro_x == -32768) ? 32767 : -report.gyro_x);
/*
* Apply the swap
*/
report.accel_x = accel_xt;
report.accel_y = accel_yt;
report.gyro_x = gyro_xt;
report.gyro_y = gyro_yt;
}
/*
* Report buffers.
*/
sensor_accel_s arb;
sensor_gyro_s grb;
/*
* Adjust and scale results to m/s^2.
*/
grb.timestamp = arb.timestamp = hrt_absolute_time();
// report the error count as the sum of the number of bad
// transfers and bad register reads. This allows the higher
// level code to decide if it should use this sensor based on
// whether it has had failures
grb.error_count = arb.error_count = perf_event_count(_bad_transfers) + perf_event_count(_bad_registers);
/*
* 1) Scale raw value to SI units using scaling from datasheet.
* 2) Subtract static offset (in SI units)
* 3) Scale the statically calibrated values with a linear
* dynamically obtained factor
*
* Note: the static sensor offset is the number the sensor outputs
* at a nominally 'zero' input. Therefore the offset has to
* be subtracted.
*
* Example: A gyro outputs a value of 74 at zero angular rate
* the offset is 74 from the origin and subtracting
* 74 from all measurements centers them around zero.
*/
/* NOTE: Axes have been swapped to match the board a few lines above. */
arb.x_raw = report.accel_x;
arb.y_raw = report.accel_y;
arb.z_raw = report.accel_z;
float xraw_f = report.accel_x;
float yraw_f = report.accel_y;
float zraw_f = report.accel_z;
// apply user specified rotation
rotate_3f(_rotation, xraw_f, yraw_f, zraw_f);
float x_in_new = ((xraw_f * _accel_range_scale) - _accel_scale.x_offset) * _accel_scale.x_scale;
float y_in_new = ((yraw_f * _accel_range_scale) - _accel_scale.y_offset) * _accel_scale.y_scale;
float z_in_new = ((zraw_f * _accel_range_scale) - _accel_scale.z_offset) * _accel_scale.z_scale;
arb.x = _accel_filter_x.apply(x_in_new);
arb.y = _accel_filter_y.apply(y_in_new);
arb.z = _accel_filter_z.apply(z_in_new);
matrix::Vector3f aval(x_in_new, y_in_new, z_in_new);
matrix::Vector3f aval_integrated;
bool accel_notify = _accel_int.put(arb.timestamp, aval, aval_integrated, arb.integral_dt);
arb.x_integral = aval_integrated(0);
arb.y_integral = aval_integrated(1);
arb.z_integral = aval_integrated(2);
arb.scaling = _accel_range_scale;
arb.temperature = _last_temperature;
/* return device ID */
arb.device_id = _accel->_device_id.devid;
grb.x_raw = report.gyro_x;
grb.y_raw = report.gyro_y;
grb.z_raw = report.gyro_z;
xraw_f = report.gyro_x;
yraw_f = report.gyro_y;
zraw_f = report.gyro_z;
// apply user specified rotation
rotate_3f(_rotation, xraw_f, yraw_f, zraw_f);
float x_gyro_in_new = ((xraw_f * _gyro_range_scale) - _gyro_scale.x_offset) * _gyro_scale.x_scale;
float y_gyro_in_new = ((yraw_f * _gyro_range_scale) - _gyro_scale.y_offset) * _gyro_scale.y_scale;
float z_gyro_in_new = ((zraw_f * _gyro_range_scale) - _gyro_scale.z_offset) * _gyro_scale.z_scale;
grb.x = _gyro_filter_x.apply(x_gyro_in_new);
grb.y = _gyro_filter_y.apply(y_gyro_in_new);
grb.z = _gyro_filter_z.apply(z_gyro_in_new);
matrix::Vector3f gval(x_gyro_in_new, y_gyro_in_new, z_gyro_in_new);
matrix::Vector3f gval_integrated;
bool gyro_notify = _gyro_int.put(arb.timestamp, gval, gval_integrated, grb.integral_dt);
grb.x_integral = gval_integrated(0);
grb.y_integral = gval_integrated(1);
grb.z_integral = gval_integrated(2);
grb.scaling = _gyro_range_scale;
grb.temperature = _last_temperature;
/* return device ID */
grb.device_id = _gyro->_device_id.devid;
_accel_reports->force(&arb);
_gyro_reports->force(&grb);
/* notify anyone waiting for data */
if (accel_notify) {
_accel->poll_notify(POLLIN);
}
if (gyro_notify) {
_gyro->parent_poll_notify();
}
if (accel_notify && !(_accel->_pub_blocked)) {
/* publish it */
orb_publish(ORB_ID(sensor_accel), _accel_topic, &arb);
}
if (gyro_notify && !(_gyro->_pub_blocked)) {
/* publish it */
orb_publish(ORB_ID(sensor_gyro), _gyro->_gyro_topic, &grb);
}
}
/* stop measuring */
perf_end(_sample_perf);
}
