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354 lines
9.9 KiB
354 lines
9.9 KiB
/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- |
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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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* |
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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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* |
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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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*/ |
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// AVR LibC Includes |
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#include <AP_Math.h> |
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#include <AP_HAL.h> |
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#include "AP_Compass_HMC5843.h" |
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extern const AP_HAL::HAL& hal; |
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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 (hal.i2c->readRegister((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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// write_register - update a register value |
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bool AP_Compass_HMC5843::write_register(uint8_t address, uint8_t value) |
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{ |
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if (hal.i2c->writeRegister((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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// 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 (hal.i2c->readRegisters(COMPASS_ADDRESS, 0x03, 6, buff) != 0) { |
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if (healthy) { |
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hal.i2c->setHighSpeed(false); |
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} |
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healthy = false; |
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_i2c_sem->give(); |
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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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// accumulate a reading from the magnetometer |
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void AP_Compass_HMC5843::accumulate(void) |
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{ |
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uint32_t tnow = hal.scheduler->micros(); |
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if (healthy && _accum_count != 0 && (tnow - _last_accum_time) < 13333) { |
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// the compass gets new data at 75Hz |
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return; |
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} |
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if (!_i2c_sem->take(5)) { |
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// the bus is busy - try again later |
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return; |
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} |
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bool result = read_raw(); |
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_i2c_sem->give(); |
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if (result) { |
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// the _mag_N values are in the range -2048 to 2047, so we can |
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// accumulate up to 15 of them in an int16_t. Let's make it 14 |
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// for ease of calculation. We expect to do reads at 10Hz, and |
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// we get new data at most 75Hz, so we don't expect to |
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// accumulate more than 8 before a read |
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_mag_x_accum += _mag_x; |
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_mag_y_accum += _mag_y; |
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_mag_z_accum += _mag_z; |
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_accum_count++; |
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if (_accum_count == 14) { |
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_mag_x_accum /= 2; |
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_mag_y_accum /= 2; |
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_mag_z_accum /= 2; |
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_accum_count = 7; |
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} |
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_last_accum_time = tnow; |
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} |
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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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uint8_t 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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hal.scheduler->delay(10); |
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_i2c_sem = hal.i2c->get_semaphore(); |
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if (!_i2c_sem->take(HAL_SEMAPHORE_BLOCK_FOREVER)) { |
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hal.scheduler->panic(PSTR("Failed to get HMC5843 semaphore")); |
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} |
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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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_i2c_sem->give(); |
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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_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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} 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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_i2c_sem->give(); |
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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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hal.scheduler->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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hal.scheduler->delay(50); |
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if (!read_raw()) |
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continue; // we didn't read valid values |
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hal.scheduler->delay(10); |
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float cal[3]; |
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cal[0] = fabsf(expected_x / (float)_mag_x); |
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cal[1] = fabsf(expected_yz / (float)_mag_y); |
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cal[2] = fabsf(expected_yz / (float)_mag_z); |
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if (cal[0] > 0.7f && cal[0] < 1.3f && |
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cal[1] > 0.7f && cal[1] < 1.3f && |
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cal[2] > 0.7f && cal[2] < 1.3f) { |
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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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_i2c_sem->give(); |
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return false; |
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} |
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_i2c_sem->give(); |
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_initialised = true; |
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// perform an initial read |
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healthy = true; |
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read(); |
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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 (hal.scheduler->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 = hal.scheduler->millis() + 1000; |
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hal.i2c->setHighSpeed(false); |
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return false; |
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} |
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} |
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if (_accum_count == 0) { |
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accumulate(); |
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if (!healthy || _accum_count == 0) { |
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// try again in 1 second, and set I2c clock speed slower |
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_retry_time = hal.scheduler->millis() + 1000; |
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hal.i2c->setHighSpeed(false); |
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return false; |
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} |
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} |
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mag_x = _mag_x_accum * calibration[0] / _accum_count; |
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mag_y = _mag_y_accum * calibration[1] / _accum_count; |
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mag_z = _mag_z_accum * calibration[2] / _accum_count; |
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_accum_count = 0; |
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_mag_x_accum = _mag_y_accum = _mag_z_accum = 0; |
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last_update = hal.scheduler->micros(); // record time of update |
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// rotate to the desired orientation |
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Vector3f rot_mag = Vector3f(mag_x,mag_y,mag_z); |
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if (product_id == AP_COMPASS_TYPE_HMC5883L) { |
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rot_mag.rotate(ROTATION_YAW_90); |
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} |
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// apply default board orientation for this compass type. This is |
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// a noop on most boards |
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rot_mag.rotate(MAG_BOARD_ORIENTATION); |
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// add user selectable orientation |
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rot_mag.rotate((enum Rotation)_orientation.get()); |
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// add in board orientation from AHRS |
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rot_mag.rotate(_board_orientation); |
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rot_mag += _offset.get(); |
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// apply motor compensation |
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if(_motor_comp_type != AP_COMPASS_MOT_COMP_DISABLED && _thr_or_curr != 0.0f) { |
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_motor_offset = _motor_compensation.get() * _thr_or_curr; |
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rot_mag += _motor_offset; |
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}else{ |
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_motor_offset.x = 0; |
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_motor_offset.y = 0; |
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_motor_offset.z = 0; |
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} |
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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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