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Driver debugging (scaling, ranges, endianess) MPU-6000 needs more love

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This commit is contained in:
Lorenz Meier 2012-08-26 23:48:16 +02:00
parent 56e66a80cd
commit 2963dc679a
5 changed files with 129 additions and 60 deletions
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6
apps/drivers/drv_accel.h
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@ -57,9 +57,9 @@ struct accel_report {
float z;
float range_m_s2;
float scaling;
uint16_t x_raw;
uint16_t y_raw;
uint16_t z_raw;
int16_t x_raw;
int16_t y_raw;
int16_t z_raw;
};
/** accel scaling factors; Vout = (Vin * Vscale) + Voffset */

6
apps/drivers/drv_mag.h
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@ -60,9 +60,9 @@ struct mag_report {
float range_ga;
float scaling;
uint16_t x_raw;
uint16_t y_raw;
uint16_t z_raw;
int16_t x_raw;
int16_t y_raw;
int16_t z_raw;
};
/** mag scaling factors; Vout = (Vin * Vscale) + Voffset */

19
apps/drivers/hmc5883/hmc5883.cpp
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@ -649,9 +649,9 @@ HMC5883::collect()
}
/* swap the data we just received */
report.x = ((int16_t)hmc_report.x[0] << 8) + hmc_report.x[1];
report.y = ((int16_t)hmc_report.y[0] << 8) + hmc_report.y[1];
report.z = ((int16_t)hmc_report.z[0] << 8) + hmc_report.z[1];
report.x = (((int16_t)hmc_report.x[0]) << 8) + hmc_report.x[1];
report.y = (((int16_t)hmc_report.y[0]) << 8) + hmc_report.y[1];
report.z = (((int16_t)hmc_report.z[0]) << 8) + hmc_report.z[1];
/*
* If any of the values are -4096, there was an internal math error in the sensor.
@ -662,10 +662,14 @@ HMC5883::collect()
(abs(report.z) > 2048))
goto out;
/* raw outputs */
/* to align the sensor axes with the board, x and y need to be flipped */
/*
* RAW outputs
*
* to align the sensor axes with the board, x and y need to be flipped
* and y needs to be negated
*/
_reports[_next_report].x_raw = report.y;
_reports[_next_report].y_raw = report.x;
_reports[_next_report].y_raw = ((report.x == -32768) ? 32767 : -report.x);
/* z remains z */
_reports[_next_report].z_raw = report.z;
@ -688,7 +692,8 @@ HMC5883::collect()
/* to align the sensor axes with the board, x and y need to be flipped */
_reports[_next_report].x = ((report.y * _range_scale) - _scale.x_offset) * _scale.x_scale;
_reports[_next_report].y = ((report.x * _range_scale) - _scale.y_offset) * _scale.y_scale;
/* flip axes and negate value for y */
_reports[_next_report].y = ((((report.x == -32768) ? 32767 : -report.x) * _range_scale) - _scale.y_offset) * _scale.y_scale;
/* z remains z */
_reports[_next_report].z = ((report.z * _range_scale) - _scale.z_offset) * _scale.z_scale;

154
apps/drivers/mpu6000/mpu6000.cpp
View File

@ -386,7 +386,7 @@ MPU6000::init()
_gyro_scale.y_scale = 1.0f;
_gyro_scale.z_offset = 0;
_gyro_scale.z_scale = 1.0f;
_gyro_range_scale = 1.0f / (32768.0f * (2000.0f / 180.0f) * M_PI_F);
_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;
// product-specific scaling
@ -421,7 +421,7 @@ MPU6000::init()
_accel_scale.y_scale = 1.0f;
_accel_scale.z_offset = 0;
_accel_scale.z_scale = 1.0f;
_accel_range_scale = 1.0f / (4096.0f / 9.81f);
_accel_range_scale = (9.81f / 4096.0f);
_accel_range_m_s2 = 8.0f * 9.81f;
usleep(1000);
@ -595,6 +595,9 @@ MPU6000::ioctl(struct file *filp, int cmd, unsigned long arg)
case ACCELIOCSRANGE:
case ACCELIOCGRANGE:
/* XXX not implemented */
// XXX change these two values on set:
// _accel_range_scale = (9.81f / 4096.0f);
// _accel_range_rad_s = 8.0f * 9.81f;
return -EINVAL;
default:
@ -634,6 +637,9 @@ MPU6000::gyro_ioctl(struct file *filp, int cmd, unsigned long arg)
case GYROIOCSRANGE:
case GYROIOCGRANGE:
/* XXX not implemented */
// XXX change these two values on set:
// _gyro_range_scale = xx
// _gyro_range_m_s2 = xx
return -EINVAL;
default:
@ -755,6 +761,20 @@ MPU6000::measure_trampoline(void *arg)
dev->measure();
}
int16_t
int16_t_from_bytes(uint8_t bytes[])
{
union {
uint8_t b[2];
int16_t w;
} u;
u.b[1] = bytes[0];
u.b[0] = bytes[1];
return u.w;
}
void
MPU6000::measure()
{
@ -763,40 +783,80 @@ MPU6000::measure()
* Report conversation within the MPU6000, including command byte and
* interrupt status.
*/
struct Report {
struct MPUReport {
uint8_t cmd;
uint8_t status;
uint16_t accel_x;
uint16_t accel_y;
uint16_t accel_z;
uint16_t temp;
uint16_t gyro_x;
uint16_t gyro_y;
uint16_t gyro_z;
} report;
uint8_t accel_x[2];
uint8_t accel_y[2];
uint8_t accel_z[2];
uint8_t temp[2];
uint8_t gyro_x[2];
uint8_t gyro_y[2];
uint8_t gyro_z[2];
} mpu_report;
#pragma pack(pop)
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 MPU6000 in one pass.
*/
report.cmd = DIR_READ | MPUREG_INT_STATUS;
transfer((uint8_t *)&report, (uint8_t *)&report, sizeof(report));
mpu_report.cmd = DIR_READ | MPUREG_INT_STATUS;
transfer((uint8_t *)&mpu_report, ((uint8_t *)&mpu_report), sizeof(mpu_report));
/*
* Adjust and scale results to mg.
* Convert from big to little endian
*/
// report.accel_x = ((int16_t)(mpu_report.accel_x[0]) << 8);
// report.accel_x |= mpu_report.accel_x[1];
// report.accel_y = ((int16_t)(mpu_report.accel_y[0]) << 8);
// report.accel_y |= mpu_report.accel_y[1];
// report.accel_z = ((int16_t)(mpu_report.accel_z[0]) << 8);
// report.accel_z |= mpu_report.accel_z[1];
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)mpu_report.temp[0]) << 8) | mpu_report.temp[1];
report.gyro_x = ((int16_t)(mpu_report.gyro_x[0]) << 8) | mpu_report.gyro_x[1];
report.gyro_y = ((int16_t)(mpu_report.gyro_y[0]) << 8) | mpu_report.gyro_y[1];
report.gyro_z = ((int16_t)(mpu_report.gyro_z[0]) << 8) | mpu_report.gyro_z[1];
/*
* 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;
/*
* Adjust and scale results to m/s^2.
*/
_gyro_report.timestamp = _accel_report.timestamp = hrt_absolute_time();
/* to align the sensor axes with the board, x and y need to be flipped */
_accel_report.x_raw = report.accel_y;
_accel_report.y_raw = report.accel_x;
/* z remains z and has the right sign */
_accel_report.z_raw = report.accel_z;
/* to align the sensor axes with the board, x and y need to be flipped */
/*
* 1) Scale raw value to SI units using scaling from datasheet.
@ -812,22 +872,26 @@ MPU6000::measure()
* the offset is 74 from the origin and subtracting
* 74 from all measurements centers them around zero.
*/
_accel_report.x = ((report.accel_y * _accel_range_scale) - _accel_scale.x_offset) * _accel_scale.x_scale;
_accel_report.y = ((report.accel_x * _accel_range_scale) - _accel_scale.y_offset) * _accel_scale.y_scale;
/* z remains z and has the right sign */
/* NOTE: Axes have been swapped to match the board a few lines above. */
_accel_report.x_raw = report.accel_x;
_accel_report.y_raw = report.accel_y;
_accel_report.z_raw = report.accel_z;
_accel_report.x = ((report.accel_x * _accel_range_scale) - _accel_scale.x_offset) * _accel_scale.x_scale;
_accel_report.y = ((report.accel_y * _accel_range_scale) - _accel_scale.y_offset) * _accel_scale.y_scale;
_accel_report.z = ((report.accel_z * _accel_range_scale) - _accel_scale.z_offset) * _accel_scale.z_scale;
_accel_report.scaling = _accel_range_scale;
_accel_report.range_m_s2 = _accel_range_m_s2;
/* to align the sensor axes with the board, x and y need to be flipped */
_gyro_report.x_raw = report.gyro_y;
_gyro_report.y_raw = report.gyro_x;
/* z remains z and has the right sign */
_gyro_report.x_raw = report.gyro_x;
_gyro_report.y_raw = report.gyro_y;
_gyro_report.z_raw = report.gyro_z;
_gyro_report.x = ((report.gyro_y * _gyro_range_scale) - _gyro_scale.x_offset) * _gyro_scale.x_scale;
_gyro_report.y = ((report.gyro_x * _gyro_range_scale) - _gyro_scale.y_offset) * _gyro_scale.y_scale;
/* z remains z and has the right sign */
_gyro_report.x = ((report.gyro_x * _gyro_range_scale) - _gyro_scale.x_offset) * _gyro_scale.x_scale;
_gyro_report.y = ((report.gyro_y * _gyro_range_scale) - _gyro_scale.y_offset) * _gyro_scale.y_scale;
_gyro_report.z = ((report.gyro_z * _gyro_range_scale) - _gyro_scale.z_offset) * _gyro_scale.z_scale;
_gyro_report.scaling = _gyro_range_scale;
_gyro_report.range_rad_s = _gyro_range_rad_s;
@ -963,12 +1027,12 @@ test()
warnx("single read");
warnx("time: %lld", a_report.timestamp);
warnx("acc x: \t% 8.4f\tm/s^2", (double)a_report.x);
warnx("acc y: \t% 8.4f\tm/s^2", (double)a_report.y);
warnx("acc z: \t% 8.4f\tm/s^2", (double)a_report.z);
warnx("acc x: \t%d\traw", a_report.x_raw);
warnx("acc y: \t%d\traw", a_report.y_raw);
warnx("acc z: \t%d\traw", a_report.z_raw);
warnx("acc x: \t%8.4f\tm/s^2", (double)a_report.x);
warnx("acc y: \t%8.4f\tm/s^2", (double)a_report.y);
warnx("acc z: \t%8.4f\tm/s^2", (double)a_report.z);
warnx("acc x: \t%d\traw", (int)a_report.x_raw);
warnx("acc y: \t%d\traw", (int)a_report.y_raw);
warnx("acc z: \t%d\traw", (int)a_report.z_raw);
warnx("acc range: %8.4f m/s^2 (%8.4f g)", (double)a_report.range_m_s2,
(double)(a_report.range_m_s2 / 9.81f));
@ -977,14 +1041,14 @@ test()
if (sz != sizeof(g_report))
err(1, "immediate gyro read failed");
warnx("gyro x: \t% 8.4f\trad/s", (double)g_report.x);
warnx("gyro y: \t% 8.4f\trad/s", (double)g_report.y);
warnx("gyro z: \t% 8.4f\trad/s", (double)g_report.z);
warnx("gyro x: \t%d\traw", g_report.x_raw);
warnx("gyro y: \t%d\traw", g_report.y_raw);
warnx("gyro z: \t%d\traw", g_report.z_raw);
warnx("gyro range: %8.4f rad/s (%8.2f deg/s)", (double)g_report.range_rad_s,
(double)((g_report.range_rad_s / M_PI_F) * 180.0f));
warnx("gyro x: \t% 9.5f\trad/s", (double)g_report.x);
warnx("gyro y: \t% 9.5f\trad/s", (double)g_report.y);
warnx("gyro z: \t% 9.5f\trad/s", (double)g_report.z);
warnx("gyro x: \t%d\traw", (int)g_report.x_raw);
warnx("gyro y: \t%d\traw", (int)g_report.y_raw);
warnx("gyro z: \t%d\traw", (int)g_report.z_raw);
warnx("gyro range: %8.4f rad/s (%d deg/s)", (double)g_report.range_rad_s,
(int)((g_report.range_rad_s / M_PI_F) * 180.0f+0.5f));
/* XXX add poll-rate tests here too */

4
apps/sensors/sensors.cpp
View File

@ -641,9 +641,9 @@ Sensors::gyro_poll(struct sensor_combined_s &raw)
gyro_report.timestamp = hrt_absolute_time();
gyro_report.x_raw = ((buf[1] == -32768) ? -32768 : buf[1]);
gyro_report.x_raw = buf[1];
gyro_report.y_raw = ((buf[0] == -32768) ? 32767 : -buf[0]);
gyro_report.z_raw = ((buf[2] == -32768) ? -32768 : buf[2]);
gyro_report.z_raw = buf[2];
/* scaling calculated as: raw * (1/(32768*(500/180*PI))) */
gyro_report.x = (gyro_report.x_raw - _parameters.gyro_offset[0]) * 0.000266316109f;