ardupilot/libraries/AP_Quaternion/examples/Quaternion/Quaternion.pde

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: t -*-

//
// Simple test for the AP_Quaternion library
//

#include <FastSerial.h>
#include <SPI.h>
#include <I2C.h>
#include <Arduino_Mega_ISR_Registry.h>
#include <AP_PeriodicProcess.h>
#include <AP_InertialSensor.h>
#include <AP_ADC.h>
#include <AP_IMU.h>
#include <AP_GPS.h>
#include <AP_Quaternion.h>
#include <AP_Math.h>
#include <AP_Common.h>
#include <AP_Compass.h>
#include <AP_Baro.h>
#include <DataFlash.h>
#include <APM_RC.h>
#include <GCS_MAVLink.h>

// uncomment this for a APM2 board
//#define APM2_HARDWARE

FastSerialPort(Serial, 0);

Arduino_Mega_ISR_Registry isr_registry;
AP_TimerProcess  scheduler;

#ifdef DESKTOP_BUILD
AP_Compass_HIL     compass;
#else
AP_Compass_HMC5843 compass;
#endif

#ifdef APM2_HARDWARE
  AP_InertialSensor_MPU6000 ins( 53 );
# else
  AP_ADC_ADS7844          adc;
  AP_InertialSensor_Oilpan ins( &adc );
#endif // CONFIG_IMU_TYPE

static GPS         *g_gps;

AP_IMU_INS imu(&ins);
AP_Quaternion  quaternion(&imu, g_gps);

AP_Baro_BMP085_HIL      barometer;


#ifdef APM2_HARDWARE
# define A_LED_PIN        27
# define C_LED_PIN        25
# define LED_ON           LOW
# define LED_OFF          HIGH
# define MAG_ORIENTATION  AP_COMPASS_APM2_SHIELD
#else
# define A_LED_PIN        37
# define C_LED_PIN        35
# define LED_ON           HIGH
# define LED_OFF          LOW
# define MAG_ORIENTATION  AP_COMPASS_COMPONENTS_DOWN_PINS_FORWARD
#endif


static void flash_leds(bool on)
{
    digitalWrite(A_LED_PIN, on?LED_OFF:LED_ON);
    digitalWrite(C_LED_PIN, on?LED_ON:LED_OFF);
}

void setup(void)
{
	Serial.begin(115200);
	Serial.println("Starting up...");

#ifndef DESKTOP_BUILD
	I2c.begin();
	I2c.timeOut(5);
	I2c.setSpeed(true);
#endif

	SPI.begin();
	SPI.setClockDivider(SPI_CLOCK_DIV16);

#ifdef APM2_HARDWARE
	// we need to stop the barometer from holding the SPI bus
	pinMode(40, OUTPUT);
	digitalWrite(40, HIGH);
#endif

	isr_registry.init();
	scheduler.init(&isr_registry);

	imu.init(IMU::COLD_START, delay, flash_leds, &scheduler);
	imu.init_accel(delay, flash_leds);

	compass.set_orientation(MAG_ORIENTATION);
	if (compass.init()) {
		Serial.printf("Enabling compass\n");
		compass.null_offsets_enable();
		quaternion.set_compass(&compass);
	}
}

void loop(void)
{
	static uint16_t counter;
	static uint32_t last_t, last_print, last_compass;
	uint32_t now = micros();
	float deltat;
	static uint32_t compass_reads;
	static uint32_t compass_time;

	if (last_t == 0) {
		last_t = now;
		return;
	}
	deltat = (now - last_t) * 1.0e-6;
	last_t = now;

	if (now - last_compass > 100*1000UL) {
		// read compass at 10Hz
		compass.read();
		last_compass = now;
	}

	quaternion.update(deltat);
	counter++;

	if (now - last_print >= 0.5e6) {
		Vector3f accel = imu.get_accel();
		Vector3f gyro  = imu.get_gyro();
		Serial.printf_P(PSTR("r:%4.1f  p:%4.1f y:%4.1f g=(%5.1f %5.1f %5.1f) a=(%5.1f %5.1f %5.1f) rate=%.1f\n"),
				ToDeg(quaternion.roll),
				ToDeg(quaternion.pitch),
				ToDeg(quaternion.yaw),
				gyro.x, gyro.y, gyro.z,
				accel.x, accel.y, accel.z,
				(1.0e6*counter)/(now-last_print));
		last_print = now;
		counter = 0;
		compass_reads=0;
		compass_time = 0;
	}
}