Exemplo n.º 1
0
void
L3GD20::measure()
{
#if L3GD20_USE_DRDY
	// if the gyro doesn't have any data ready then re-schedule
	// for 100 microseconds later. This ensures we don't double
	// read a value and then miss the next value
	if (_bus == PX4_SPI_BUS_SENSORS && stm32_gpioread(GPIO_EXTI_GYRO_DRDY) == 0) {
		perf_count(_reschedules);
		hrt_call_delay(&_call, 100);
		return;
	}
#endif

	/* status register and data as read back from the device */
#pragma pack(push, 1)
	struct {
		uint8_t		cmd;
		uint8_t		temp;
		uint8_t		status;
		int16_t		x;
		int16_t		y;
		int16_t		z;
	} raw_report;
#pragma pack(pop)

	gyro_report report;

	/* start the performance counter */
	perf_begin(_sample_perf);

	/* fetch data from the sensor */
	memset(&raw_report, 0, sizeof(raw_report));
	raw_report.cmd = ADDR_OUT_TEMP | DIR_READ | ADDR_INCREMENT;
	transfer((uint8_t *)&raw_report, (uint8_t *)&raw_report, sizeof(raw_report));

#if L3GD20_USE_DRDY
        if ((raw_report.status & 0xF) != 0xF) {
            /*
              we waited for DRDY, but did not see DRDY on all axes
              when we captured. That means a transfer error of some sort
             */
            perf_count(_errors);            
            return;
        }
#endif
	/*
	 * 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.
	 */
	report.timestamp = hrt_absolute_time();
        report.error_count = 0; // not recorded
	
	switch (_orientation) {

		case SENSOR_BOARD_ROTATION_000_DEG:
			/* keep axes in place */
			report.x_raw = raw_report.x;
			report.y_raw = raw_report.y;
			break;

		case SENSOR_BOARD_ROTATION_090_DEG:
			/* swap x and y */
			report.x_raw = raw_report.y;
			report.y_raw = raw_report.x;
			break;

		case SENSOR_BOARD_ROTATION_180_DEG:
			/* swap x and y and negate both */
			report.x_raw = ((raw_report.x == -32768) ? 32767 : -raw_report.x);
			report.y_raw = ((raw_report.y == -32768) ? 32767 : -raw_report.y);
			break;

		case SENSOR_BOARD_ROTATION_270_DEG:
			/* swap x and y and negate y */
			report.x_raw = raw_report.y;
			report.y_raw = ((raw_report.x == -32768) ? 32767 : -raw_report.x);
			break;
	}

	report.z_raw = raw_report.z;

	report.x = ((report.x_raw * _gyro_range_scale) - _gyro_scale.x_offset) * _gyro_scale.x_scale;
	report.y = ((report.y_raw * _gyro_range_scale) - _gyro_scale.y_offset) * _gyro_scale.y_scale;
	report.z = ((report.z_raw * _gyro_range_scale) - _gyro_scale.z_offset) * _gyro_scale.z_scale;

	report.x = _gyro_filter_x.apply(report.x);
	report.y = _gyro_filter_y.apply(report.y);
	report.z = _gyro_filter_z.apply(report.z);

	// apply user specified rotation
	rotate_3f(_rotation, report.x, report.y, report.z);

	report.scaling = _gyro_range_scale;
	report.range_rad_s = _gyro_range_rad_s;

	_reports->force(&report);

	/* notify anyone waiting for data */
	poll_notify(POLLIN);

	/* publish for subscribers */
	if (!(_pub_blocked)) {
		/* publish it */
		orb_publish(_orb_id, _gyro_topic, &report);
	}

	_read++;

	/* stop the perf counter */
	perf_end(_sample_perf);
}
Exemplo n.º 2
0
void
LSM303D::measure()
{
	// if the accel doesn't have any data ready then re-schedule
	// for 100 microseconds later. This ensures we don't double
	// read a value and then miss the next value
	if (stm32_gpioread(GPIO_EXTI_ACCEL_DRDY) == 0) {
		perf_count(_accel_reschedules);
		hrt_call_delay(&_accel_call, 100);
		return;
	}
	if (read_reg(ADDR_CTRL_REG1) != _reg1_expected) {
		perf_count(_reg1_resets);
		reset();
		return;
	}

	/* status register and data as read back from the device */

#pragma pack(push, 1)
	struct {
		uint8_t		cmd;
		uint8_t		status;
		int16_t		x;
		int16_t		y;
		int16_t		z;
	} raw_accel_report;
#pragma pack(pop)

	accel_report accel_report;

	/* start the performance counter */
	perf_begin(_accel_sample_perf);

	/* fetch data from the sensor */
	memset(&raw_accel_report, 0, sizeof(raw_accel_report));
	raw_accel_report.cmd = ADDR_STATUS_A | DIR_READ | ADDR_INCREMENT;
	transfer((uint8_t *)&raw_accel_report, (uint8_t *)&raw_accel_report, sizeof(raw_accel_report));

	/*
	 * 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.
	 */


	accel_report.timestamp = hrt_absolute_time();
        accel_report.error_count = 0; // not reported

	accel_report.x_raw = raw_accel_report.x;
	accel_report.y_raw = raw_accel_report.y;
	accel_report.z_raw = raw_accel_report.z;

	float x_in_new = ((accel_report.x_raw * _accel_range_scale) - _accel_scale.x_offset) * _accel_scale.x_scale;
	float y_in_new = ((accel_report.y_raw * _accel_range_scale) - _accel_scale.y_offset) * _accel_scale.y_scale;
	float z_in_new = ((accel_report.z_raw * _accel_range_scale) - _accel_scale.z_offset) * _accel_scale.z_scale;

	accel_report.x = _accel_filter_x.apply(x_in_new);
	accel_report.y = _accel_filter_y.apply(y_in_new);
	accel_report.z = _accel_filter_z.apply(z_in_new);

	accel_report.scaling = _accel_range_scale;
	accel_report.range_m_s2 = _accel_range_m_s2;

	_accel_reports->force(&accel_report);

	/* notify anyone waiting for data */
	poll_notify(POLLIN);

	if (_accel_topic > 0 && !(_pub_blocked)) {
		/* publish it */
		orb_publish(ORB_ID(sensor_accel), _accel_topic, &accel_report);
	}

	_accel_read++;

	/* stop the perf counter */
	perf_end(_accel_sample_perf);
}