mirror of https://github.com/ArduPilot/ardupilot
235 lines
6.2 KiB
C++
235 lines
6.2 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 "WConstants.h"
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#include <Wire.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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static bool
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read_register(int address, byte *value)
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{
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bool ret = false;
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*value = 0;
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Wire.beginTransmission(COMPASS_ADDRESS);
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Wire.send(address); //sends address to read from
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if (0 != Wire.endTransmission())
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return false;
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Wire.requestFrom(COMPASS_ADDRESS, 1); // request 1 byte from device
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if( Wire.available() ) {
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*value = Wire.receive(); // receive one byte
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ret = true;
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}
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if (0 != Wire.endTransmission())
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return false;
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return ret;
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}
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// write_register - update a register value
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static bool
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write_register(int address, byte value)
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{
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Wire.beginTransmission(COMPASS_ADDRESS);
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Wire.send(address);
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Wire.send(value);
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if (0 != Wire.endTransmission())
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return false;
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delay(10);
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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;
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bool success = false;
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byte base_config; // used to test compass type
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byte calibration_gain = 0x20;
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uint16_t expected_xy = 715;
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uint16_t expected_z = 715;
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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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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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product_id = AP_COMPASS_TYPE_HMC5883L;
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calibration_gain = 0x60;
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expected_xy = 766;
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expected_z = 713;
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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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while( success == 0 && numAttempts < 5 )
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{
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unsigned long update_stamp = last_update;
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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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// calibration initialisation
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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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// read values from the compass
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read();
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if (last_update == update_stamp)
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continue; // we didn't read valid values
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delay(10);
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// calibrate
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if( abs(mag_x) > 500 && abs(mag_x) < 2000 && abs(mag_y) > 500 && abs(mag_y) < 2000 && abs(mag_z) > 500 && abs(mag_z) < 2000)
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{
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calibration[0] = fabs(expected_xy / (float)mag_x);
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calibration[1] = fabs(expected_xy / (float)mag_y);
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calibration[2] = fabs(expected_z / (float)mag_z);
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// mark success
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success = true;
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}
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}
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// leave test mode
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if (! write_register(ConfigRegA, base_config))
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return false;
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delay(50);
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if (! write_register(ConfigRegB, magGain) ||
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! write_register(ModeRegister, ContinuousConversion))
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return false;
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delay(50);
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return success;
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}
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// Read Sensor data
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void
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AP_Compass_HMC5843::read()
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{
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int i = 0;
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byte buff[6];
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Vector3f rot_mag;
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Wire.beginTransmission(COMPASS_ADDRESS);
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Wire.send(0x03); //sends address to read from
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if (0 != Wire.endTransmission())
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return;
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//Wire.beginTransmission(COMPASS_ADDRESS);
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Wire.requestFrom(COMPASS_ADDRESS, 6); // request 6 bytes from device
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while(Wire.available())
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{
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buff[i] = Wire.receive(); // receive one byte
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i++;
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}
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if (0 != Wire.endTransmission())
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return;
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if (i==6) // All bytes received?
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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, last_update is not updated
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return;
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}
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mag_x = -rx * calibration[0];
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mag_y = ry * calibration[1];
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mag_z = -rz * 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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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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}
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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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if( product_id == AP_COMPASS_TYPE_HMC5883L ) {
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_orientation_matrix.set_and_save(rotation_matrix * Matrix3f(ROTATION_YAW_90));
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}else{
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_orientation_matrix.set_and_save(rotation_matrix);
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}
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}
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