mirror of https://github.com/ArduPilot/ardupilot
305 lines
7.6 KiB
C++
305 lines
7.6 KiB
C++
// -*- tab-width: 4; Mode: C++; c-basic-offset: 3; indent-tabs-mode: t -*-
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/*
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AP_Compass_HMC5843.cpp - Arduino Library for HMC5843 I2C magnetometer
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Code by Jordi Muñoz and Jose Julio. DIYDrones.com
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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Sensor is conected to I2C port
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Sensor is initialized in Continuos mode (10Hz)
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*/
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// AVR LibC Includes
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#include <math.h>
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#include <FastSerial.h>
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#if defined(ARDUINO) && ARDUINO >= 100
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#include "Arduino.h"
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#else
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#include "WConstants.h"
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#endif
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#include <I2C.h>
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#include "AP_Compass_HMC5843.h"
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#define COMPASS_ADDRESS 0x1E
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#define ConfigRegA 0x00
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#define ConfigRegB 0x01
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#define magGain 0x20
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#define PositiveBiasConfig 0x11
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#define NegativeBiasConfig 0x12
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#define NormalOperation 0x10
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#define ModeRegister 0x02
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#define ContinuousConversion 0x00
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#define SingleConversion 0x01
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// ConfigRegA valid sample averaging for 5883L
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#define SampleAveraging_1 0x00
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#define SampleAveraging_2 0x01
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#define SampleAveraging_4 0x02
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#define SampleAveraging_8 0x03
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// ConfigRegA valid data output rates for 5883L
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#define DataOutputRate_0_75HZ 0x00
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#define DataOutputRate_1_5HZ 0x01
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#define DataOutputRate_3HZ 0x02
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#define DataOutputRate_7_5HZ 0x03
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#define DataOutputRate_15HZ 0x04
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#define DataOutputRate_30HZ 0x05
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#define DataOutputRate_75HZ 0x06
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// read_register - read a register value
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bool AP_Compass_HMC5843::read_register(uint8_t address, uint8_t *value)
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{
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if (I2c.read((uint8_t)COMPASS_ADDRESS, address, 1, value) != 0) {
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healthy = false;
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return false;
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}
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return true;
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}
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// write_register - update a register value
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bool AP_Compass_HMC5843::write_register(uint8_t address, byte value)
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{
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if (I2c.write((uint8_t)COMPASS_ADDRESS, address, value) != 0) {
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healthy = false;
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return false;
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}
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return true;
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}
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/*
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the 5883L has a different orientation to the 5843. This allows us to
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use a single MAG_ORIENTATION for both
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*/
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static void rotate_for_5883L(AP_Matrix3f *_orientation_matrix)
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{
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_orientation_matrix->set_and_save(_orientation_matrix->get() * Matrix3f(ROTATION_YAW_90));
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}
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// Read Sensor data
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bool AP_Compass_HMC5843::read_raw()
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{
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uint8_t buff[6];
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if (I2c.read(COMPASS_ADDRESS, 0x03, 6, buff) != 0) {
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healthy = false;
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return false;
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}
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int16_t rx, ry, rz;
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rx = (int16_t)(buff[0] << 8) | buff[1];
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if (product_id == AP_COMPASS_TYPE_HMC5883L) {
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rz = (int16_t)(buff[2] << 8) | buff[3];
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ry = (int16_t)(buff[4] << 8) | buff[5];
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} else {
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ry = (int16_t)(buff[2] << 8) | buff[3];
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rz = (int16_t)(buff[4] << 8) | buff[5];
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}
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if (rx == -4096 || ry == -4096 || rz == -4096) {
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// no valid data available
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return false;
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}
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mag_x = -rx;
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mag_y = ry;
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mag_z = -rz;
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return true;
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}
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/*
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re-initialise after a IO error
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*/
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bool AP_Compass_HMC5843::re_initialise()
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{
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if (! write_register(ConfigRegA, _base_config) ||
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! write_register(ConfigRegB, magGain) ||
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! write_register(ModeRegister, ContinuousConversion))
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return false;
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return true;
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}
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// Public Methods //////////////////////////////////////////////////////////////
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bool
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AP_Compass_HMC5843::init()
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{
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int numAttempts = 0, good_count = 0;
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bool success = false;
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byte calibration_gain = 0x20;
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uint16_t expected_x = 715;
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uint16_t expected_yz = 715;
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float gain_multiple = 1.0;
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delay(10);
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// determine if we are using 5843 or 5883L
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if (! write_register(ConfigRegA, SampleAveraging_8<<5 | DataOutputRate_75HZ<<2 | NormalOperation) ||
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! read_register(ConfigRegA, &_base_config)) {
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healthy = false;
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return false;
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}
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if ( _base_config == (SampleAveraging_8<<5 | DataOutputRate_75HZ<<2 | NormalOperation)) {
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// a 5883L supports the sample averaging config
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int old_product_id = product_id;
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product_id = AP_COMPASS_TYPE_HMC5883L;
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calibration_gain = 0x60;
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expected_x = 766;
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expected_yz = 713;
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gain_multiple = 660.0 / 1090; // adjustment for runtime vs calibration gain
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if (old_product_id != product_id) {
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/* now we know the compass type we need to rotate the
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* orientation matrix that we were given
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*/
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rotate_for_5883L(&_orientation_matrix);
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}
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} else if (_base_config == (NormalOperation | DataOutputRate_75HZ<<2)) {
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product_id = AP_COMPASS_TYPE_HMC5843;
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} else {
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// not behaving like either supported compass type
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return false;
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}
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calibration[0] = 0;
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calibration[1] = 0;
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calibration[2] = 0;
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while ( success == 0 && numAttempts < 20 && good_count < 5)
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{
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// record number of attempts at initialisation
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numAttempts++;
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// force positiveBias (compass should return 715 for all channels)
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if (! write_register(ConfigRegA, PositiveBiasConfig))
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continue; // compass not responding on the bus
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delay(50);
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// set gains
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if (! write_register(ConfigRegB, calibration_gain) ||
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! write_register(ModeRegister, SingleConversion))
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continue;
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// read values from the compass
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delay(50);
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if (!read_raw())
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continue; // we didn't read valid values
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delay(10);
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float cal[3];
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cal[0] = fabs(expected_x / (float)mag_x);
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cal[1] = fabs(expected_yz / (float)mag_y);
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cal[2] = fabs(expected_yz / (float)mag_z);
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if (cal[0] > 0.7 && cal[0] < 1.3 &&
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cal[1] > 0.7 && cal[1] < 1.3 &&
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cal[2] > 0.7 && cal[2] < 1.3) {
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good_count++;
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calibration[0] += cal[0];
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calibration[1] += cal[1];
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calibration[2] += cal[2];
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}
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#if 0
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/* useful for debugging */
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Serial.print("mag_x: ");
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Serial.print(mag_x);
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Serial.print(" mag_y: ");
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Serial.print(mag_y);
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Serial.print(" mag_z: ");
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Serial.println(mag_z);
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Serial.print("CalX: ");
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Serial.print(calibration[0]/good_count);
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Serial.print(" CalY: ");
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Serial.print(calibration[1]/good_count);
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Serial.print(" CalZ: ");
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Serial.println(calibration[2]/good_count);
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#endif
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}
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if (good_count >= 5) {
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calibration[0] = calibration[0] * gain_multiple / good_count;
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calibration[1] = calibration[1] * gain_multiple / good_count;
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calibration[2] = calibration[2] * gain_multiple / good_count;
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success = true;
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} else {
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/* best guess */
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calibration[0] = 1.0;
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calibration[1] = 1.0;
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calibration[2] = 1.0;
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}
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// leave test mode
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if (!re_initialise()) {
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return false;
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}
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_initialised = true;
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return success;
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}
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// Read Sensor data
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bool AP_Compass_HMC5843::read()
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{
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if (!_initialised) {
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// someone has tried to enable a compass for the first time
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// mid-flight .... we can't do that yet (especially as we won't
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// have the right orientation!)
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return false;
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}
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if (!healthy) {
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if (millis() < _retry_time) {
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return false;
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}
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if (!re_initialise()) {
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_retry_time = millis() + 1000;
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return false;
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}
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}
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if (!read_raw()) {
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// try again in 1 second, and set I2c clock speed slower
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_retry_time = millis() + 1000;
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I2c.setSpeed(false);
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return false;
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}
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mag_x *= calibration[0];
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mag_y *= calibration[1];
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mag_z *= calibration[2];
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last_update = millis(); // record time of update
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// rotate and offset the magnetometer values
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// XXX this could well be done in common code...
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Vector3f rot_mag = _orientation_matrix.get() * Vector3f(mag_x,mag_y,mag_z);
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rot_mag = rot_mag + _offset.get();
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mag_x = rot_mag.x;
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mag_y = rot_mag.y;
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mag_z = rot_mag.z;
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healthy = true;
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return true;
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}
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// set orientation
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void
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AP_Compass_HMC5843::set_orientation(const Matrix3f &rotation_matrix)
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{
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_orientation_matrix.set_and_save(rotation_matrix);
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if (product_id == AP_COMPASS_TYPE_HMC5883L) {
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rotate_for_5883L(&_orientation_matrix);
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}
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}
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