Joseph Roberts
10DOF FreeIMU port for FreeIMU v4 board and GY-86. This library was modified extensively to specifically suit the Mbed platform. Used threads and interrupts to achieve async mode.
Dependencies: HMC58X3 MODI2C MPU6050 MS561101BA
Fork of
FreeIMU
by 
Yifei Teng
FreeIMU.cpp@1:794e9cdbc2a0, 2013-11-05 (annotated)
- Committer:
- tyftyftyf
- Date:
- Tue Nov 05 11:31:39 2013 +0000
- Revision:
- 1:794e9cdbc2a0
- Parent:
- 0:21840c01d3d7
- Child:
- 2:5c419926dcd7
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| tyftyftyf | 0:21840c01d3d7 | 1 | /* |
| tyftyftyf | 0:21840c01d3d7 | 2 | FreeIMU.cpp - A libre and easy to use orientation sensing library for Arduino |
| tyftyftyf | 0:21840c01d3d7 | 3 | Copyright (C) 2011-2012 Fabio Varesano <fabio at varesano dot net> |
| tyftyftyf | 0:21840c01d3d7 | 4 | |
| tyftyftyf | 0:21840c01d3d7 | 5 | Development of this code has been supported by the Department of Computer Science, |
| tyftyftyf | 0:21840c01d3d7 | 6 | Universita' degli Studi di Torino, Italy within the Piemonte Project |
| tyftyftyf | 0:21840c01d3d7 | 7 | http://www.piemonte.di.unito.it/ |
| tyftyftyf | 0:21840c01d3d7 | 8 | |
| tyftyftyf | 0:21840c01d3d7 | 9 | |
| tyftyftyf | 0:21840c01d3d7 | 10 | This program is free software: you can redistribute it and/or modify |
| tyftyftyf | 0:21840c01d3d7 | 11 | it under the terms of the version 3 GNU General Public License as |
| tyftyftyf | 0:21840c01d3d7 | 12 | published by the Free Software Foundation. |
| tyftyftyf | 0:21840c01d3d7 | 13 | |
| tyftyftyf | 0:21840c01d3d7 | 14 | This program is distributed in the hope that it will be useful, |
| tyftyftyf | 0:21840c01d3d7 | 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| tyftyftyf | 0:21840c01d3d7 | 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| tyftyftyf | 0:21840c01d3d7 | 17 | GNU General Public License for more details. |
| tyftyftyf | 0:21840c01d3d7 | 18 | |
| tyftyftyf | 0:21840c01d3d7 | 19 | You should have received a copy of the GNU General Public License |
| tyftyftyf | 0:21840c01d3d7 | 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| tyftyftyf | 0:21840c01d3d7 | 21 | |
| tyftyftyf | 0:21840c01d3d7 | 22 | 02/20/2013 - Modified by Aloïs Wolff for MBED with MPU6050 only (wolffalois@gmail.com) |
| tyftyftyf | 0:21840c01d3d7 | 23 | */ |
| tyftyftyf | 0:21840c01d3d7 | 24 | |
| tyftyftyf | 0:21840c01d3d7 | 25 | //#include <inttypes.h> |
| tyftyftyf | 0:21840c01d3d7 | 26 | //#include <stdint.h> |
| tyftyftyf | 0:21840c01d3d7 | 27 | //#define DEBUG |
| tyftyftyf | 0:21840c01d3d7 | 28 | #include "FreeIMU.h" |
| tyftyftyf | 0:21840c01d3d7 | 29 | #define M_PI 3.1415926535897932384626433832795 |
| tyftyftyf | 0:21840c01d3d7 | 30 | |
| tyftyftyf | 0:21840c01d3d7 | 31 | #ifdef DEBUG |
| tyftyftyf | 0:21840c01d3d7 | 32 | #define DEBUG_PRINT(x) Serial.println(x) |
| tyftyftyf | 0:21840c01d3d7 | 33 | #else |
| tyftyftyf | 0:21840c01d3d7 | 34 | #define DEBUG_PRINT(x) |
| tyftyftyf | 0:21840c01d3d7 | 35 | #endif |
| tyftyftyf | 0:21840c01d3d7 | 36 | // #include "WireUtils.h" |
| tyftyftyf | 0:21840c01d3d7 | 37 | //#include "DebugUtils.h" |
| tyftyftyf | 0:21840c01d3d7 | 38 | |
| tyftyftyf | 0:21840c01d3d7 | 39 | //#include "vector_math.h" |
| tyftyftyf | 0:21840c01d3d7 | 40 | |
| tyftyftyf | 0:21840c01d3d7 | 41 | I2C i2c(I2C_SDA,I2C_SCL); |
| tyftyftyf | 0:21840c01d3d7 | 42 | |
| tyftyftyf | 1:794e9cdbc2a0 | 43 | FreeIMU::FreeIMU() : accgyro(MPU6050(i2c)), magn(HMC58X3(i2c)), baro(MS561101BA(i2c)){ |
| tyftyftyf | 0:21840c01d3d7 | 44 | |
| tyftyftyf | 0:21840c01d3d7 | 45 | i2c.frequency(400000); |
| tyftyftyf | 0:21840c01d3d7 | 46 | |
| tyftyftyf | 0:21840c01d3d7 | 47 | // initialize quaternion |
| tyftyftyf | 0:21840c01d3d7 | 48 | q0 = 1.0f; |
| tyftyftyf | 0:21840c01d3d7 | 49 | q1 = 0.0f; |
| tyftyftyf | 0:21840c01d3d7 | 50 | q2 = 0.0f; |
| tyftyftyf | 0:21840c01d3d7 | 51 | q3 = 0.0f; |
| tyftyftyf | 0:21840c01d3d7 | 52 | exInt = 0.0; |
| tyftyftyf | 0:21840c01d3d7 | 53 | eyInt = 0.0; |
| tyftyftyf | 0:21840c01d3d7 | 54 | ezInt = 0.0; |
| tyftyftyf | 0:21840c01d3d7 | 55 | twoKp = twoKpDef; |
| tyftyftyf | 0:21840c01d3d7 | 56 | twoKi = twoKiDef; |
| tyftyftyf | 0:21840c01d3d7 | 57 | integralFBx = 0.0f, integralFBy = 0.0f, integralFBz = 0.0f; |
| tyftyftyf | 0:21840c01d3d7 | 58 | |
| tyftyftyf | 0:21840c01d3d7 | 59 | update.start(); |
| tyftyftyf | 0:21840c01d3d7 | 60 | dt_us=0; |
| tyftyftyf | 0:21840c01d3d7 | 61 | /* |
| tyftyftyf | 0:21840c01d3d7 | 62 | lastUpdate = 0; |
| tyftyftyf | 0:21840c01d3d7 | 63 | now = 0; |
| tyftyftyf | 0:21840c01d3d7 | 64 | */ |
| tyftyftyf | 0:21840c01d3d7 | 65 | #ifndef CALIBRATION_H |
| tyftyftyf | 0:21840c01d3d7 | 66 | // initialize scale factors to neutral values |
| tyftyftyf | 0:21840c01d3d7 | 67 | acc_scale_x = 1; |
| tyftyftyf | 0:21840c01d3d7 | 68 | acc_scale_y = 1; |
| tyftyftyf | 0:21840c01d3d7 | 69 | acc_scale_z = 1; |
| tyftyftyf | 0:21840c01d3d7 | 70 | magn_scale_x = 1; |
| tyftyftyf | 0:21840c01d3d7 | 71 | magn_scale_y = 1; |
| tyftyftyf | 0:21840c01d3d7 | 72 | magn_scale_z = 1; |
| tyftyftyf | 0:21840c01d3d7 | 73 | #else |
| tyftyftyf | 0:21840c01d3d7 | 74 | // get values from global variables of same name defined in calibration.h |
| tyftyftyf | 0:21840c01d3d7 | 75 | acc_off_x = ::acc_off_x; |
| tyftyftyf | 0:21840c01d3d7 | 76 | acc_off_y = ::acc_off_y; |
| tyftyftyf | 0:21840c01d3d7 | 77 | acc_off_z = ::acc_off_z; |
| tyftyftyf | 0:21840c01d3d7 | 78 | acc_scale_x = ::acc_scale_x; |
| tyftyftyf | 0:21840c01d3d7 | 79 | acc_scale_y = ::acc_scale_y; |
| tyftyftyf | 0:21840c01d3d7 | 80 | acc_scale_z = ::acc_scale_z; |
| tyftyftyf | 0:21840c01d3d7 | 81 | magn_off_x = ::magn_off_x; |
| tyftyftyf | 0:21840c01d3d7 | 82 | magn_off_y = ::magn_off_y; |
| tyftyftyf | 0:21840c01d3d7 | 83 | magn_off_z = ::magn_off_z; |
| tyftyftyf | 0:21840c01d3d7 | 84 | magn_scale_x = ::magn_scale_x; |
| tyftyftyf | 0:21840c01d3d7 | 85 | magn_scale_y = ::magn_scale_y; |
| tyftyftyf | 0:21840c01d3d7 | 86 | magn_scale_z = ::magn_scale_z; |
| tyftyftyf | 0:21840c01d3d7 | 87 | #endif |
| tyftyftyf | 0:21840c01d3d7 | 88 | } |
| tyftyftyf | 0:21840c01d3d7 | 89 | |
| tyftyftyf | 0:21840c01d3d7 | 90 | void FreeIMU::init() { |
| tyftyftyf | 0:21840c01d3d7 | 91 | |
| tyftyftyf | 0:21840c01d3d7 | 92 | init(FIMU_ACCGYRO_ADDR, false); |
| tyftyftyf | 0:21840c01d3d7 | 93 | |
| tyftyftyf | 0:21840c01d3d7 | 94 | } |
| tyftyftyf | 0:21840c01d3d7 | 95 | |
| tyftyftyf | 0:21840c01d3d7 | 96 | void FreeIMU::init(bool fastmode) { |
| tyftyftyf | 0:21840c01d3d7 | 97 | |
| tyftyftyf | 0:21840c01d3d7 | 98 | init(FIMU_ACCGYRO_ADDR, fastmode); |
| tyftyftyf | 0:21840c01d3d7 | 99 | |
| tyftyftyf | 0:21840c01d3d7 | 100 | } |
| tyftyftyf | 0:21840c01d3d7 | 101 | |
| tyftyftyf | 0:21840c01d3d7 | 102 | |
| tyftyftyf | 0:21840c01d3d7 | 103 | /** |
| tyftyftyf | 0:21840c01d3d7 | 104 | * Initialize the FreeIMU I2C bus, sensors and performs gyro offsets calibration |
| tyftyftyf | 0:21840c01d3d7 | 105 | */ |
| tyftyftyf | 0:21840c01d3d7 | 106 | |
| tyftyftyf | 0:21840c01d3d7 | 107 | void FreeIMU::init(int accgyro_addr, bool fastmode) { |
| tyftyftyf | 0:21840c01d3d7 | 108 | |
| tyftyftyf | 1:794e9cdbc2a0 | 109 | wait_ms(10); |
| tyftyftyf | 1:794e9cdbc2a0 | 110 | |
| tyftyftyf | 0:21840c01d3d7 | 111 | accgyro = MPU6050(0x68); |
| tyftyftyf | 0:21840c01d3d7 | 112 | accgyro.initialize(); |
| tyftyftyf | 0:21840c01d3d7 | 113 | accgyro.setI2CMasterModeEnabled(0); |
| tyftyftyf | 0:21840c01d3d7 | 114 | accgyro.setI2CBypassEnabled(1); |
| tyftyftyf | 1:794e9cdbc2a0 | 115 | accgyro.setFullScaleGyroRange(MPU6050_GYRO_FS_1000); |
| tyftyftyf | 1:794e9cdbc2a0 | 116 | accgyro.setDLPFMode(1); |
| tyftyftyf | 1:794e9cdbc2a0 | 117 | accgyro.setRate(0); |
| tyftyftyf | 1:794e9cdbc2a0 | 118 | wait_ms(10); |
| tyftyftyf | 0:21840c01d3d7 | 119 | |
| tyftyftyf | 0:21840c01d3d7 | 120 | |
| tyftyftyf | 0:21840c01d3d7 | 121 | // init HMC5843 |
| tyftyftyf | 0:21840c01d3d7 | 122 | magn.init(false); // Don't set mode yet, we'll do that later on. |
| tyftyftyf | 1:794e9cdbc2a0 | 123 | magn.setGain(0); |
| tyftyftyf | 0:21840c01d3d7 | 124 | // Calibrate HMC using self test, not recommended to change the gain after calibration. |
| tyftyftyf | 1:794e9cdbc2a0 | 125 | magn.calibrate(0, 8); // Use gain 1=default, valid 0-7, 7 not recommended. |
| tyftyftyf | 0:21840c01d3d7 | 126 | // Single mode conversion was used in calibration, now set continuous mode |
| tyftyftyf | 0:21840c01d3d7 | 127 | magn.setMode(0); |
| tyftyftyf | 1:794e9cdbc2a0 | 128 | wait_ms(20); |
| tyftyftyf | 0:21840c01d3d7 | 129 | magn.setDOR(6); |
| tyftyftyf | 0:21840c01d3d7 | 130 | |
| tyftyftyf | 0:21840c01d3d7 | 131 | baro.init(FIMU_BARO_ADDR); |
| tyftyftyf | 0:21840c01d3d7 | 132 | |
| tyftyftyf | 0:21840c01d3d7 | 133 | // zero gyro |
| tyftyftyf | 0:21840c01d3d7 | 134 | zeroGyro(); |
| tyftyftyf | 0:21840c01d3d7 | 135 | |
| tyftyftyf | 0:21840c01d3d7 | 136 | #ifndef CALIBRATION_H |
| tyftyftyf | 0:21840c01d3d7 | 137 | // load calibration from eeprom |
| tyftyftyf | 0:21840c01d3d7 | 138 | calLoad(); |
| tyftyftyf | 0:21840c01d3d7 | 139 | #endif |
| tyftyftyf | 0:21840c01d3d7 | 140 | getQ_simple(NULL); |
| tyftyftyf | 0:21840c01d3d7 | 141 | } |
| tyftyftyf | 0:21840c01d3d7 | 142 | |
| tyftyftyf | 0:21840c01d3d7 | 143 | void FreeIMU::getQ_simple(float* q) |
| tyftyftyf | 0:21840c01d3d7 | 144 | { |
| tyftyftyf | 0:21840c01d3d7 | 145 | float values[9]; |
| tyftyftyf | 0:21840c01d3d7 | 146 | getValues(values); |
| tyftyftyf | 0:21840c01d3d7 | 147 | |
| tyftyftyf | 0:21840c01d3d7 | 148 | float pitch = atan2(values[0], sqrt(values[1]*values[1]+values[2]*values[2])); |
| tyftyftyf | 0:21840c01d3d7 | 149 | float roll = -atan2(values[1], sqrt(values[0]*values[0]+values[2]*values[2])); |
| tyftyftyf | 0:21840c01d3d7 | 150 | |
| tyftyftyf | 0:21840c01d3d7 | 151 | float xh = values[6]*cos(pitch)+values[7]*sin(roll)*sin(pitch)-values[8]*cos(roll)*sin(pitch); |
| tyftyftyf | 0:21840c01d3d7 | 152 | float yh = values[7]*cos(roll)+values[8]*sin(roll); |
| tyftyftyf | 0:21840c01d3d7 | 153 | float yaw = atan2(yh, xh); |
| tyftyftyf | 0:21840c01d3d7 | 154 | |
| tyftyftyf | 0:21840c01d3d7 | 155 | float rollOver2 = roll * 0.5f; |
| tyftyftyf | 0:21840c01d3d7 | 156 | float sinRollOver2 = (float)sin(rollOver2); |
| tyftyftyf | 0:21840c01d3d7 | 157 | float cosRollOver2 = (float)cos(rollOver2); |
| tyftyftyf | 0:21840c01d3d7 | 158 | float pitchOver2 = pitch * 0.5f; |
| tyftyftyf | 0:21840c01d3d7 | 159 | float sinPitchOver2 = (float)sin(pitchOver2); |
| tyftyftyf | 0:21840c01d3d7 | 160 | float cosPitchOver2 = (float)cos(pitchOver2); |
| tyftyftyf | 0:21840c01d3d7 | 161 | float yawOver2 = yaw * 0.5f; |
| tyftyftyf | 0:21840c01d3d7 | 162 | float sinYawOver2 = (float)sin(yawOver2); |
| tyftyftyf | 0:21840c01d3d7 | 163 | float cosYawOver2 = (float)cos(yawOver2); |
| tyftyftyf | 0:21840c01d3d7 | 164 | |
| tyftyftyf | 0:21840c01d3d7 | 165 | q0 = cosYawOver2 * sinPitchOver2 * cosRollOver2 + sinYawOver2 * cosPitchOver2 * sinRollOver2; |
| tyftyftyf | 0:21840c01d3d7 | 166 | q1 = sinYawOver2 * cosPitchOver2 * cosRollOver2 - cosYawOver2 * sinPitchOver2 * sinRollOver2; |
| tyftyftyf | 0:21840c01d3d7 | 167 | q2 = - cosYawOver2 * cosPitchOver2 * cosRollOver2 - sinYawOver2 * sinPitchOver2 * sinRollOver2; |
| tyftyftyf | 0:21840c01d3d7 | 168 | q3 = cosYawOver2 * cosPitchOver2 * sinRollOver2 - sinYawOver2 * sinPitchOver2 * cosRollOver2; |
| tyftyftyf | 0:21840c01d3d7 | 169 | |
| tyftyftyf | 0:21840c01d3d7 | 170 | if (q!=NULL){ |
| tyftyftyf | 0:21840c01d3d7 | 171 | q[0] = q0; |
| tyftyftyf | 0:21840c01d3d7 | 172 | q[1] = q1; |
| tyftyftyf | 0:21840c01d3d7 | 173 | q[2] = q2; |
| tyftyftyf | 0:21840c01d3d7 | 174 | q[3] = q3; |
| tyftyftyf | 0:21840c01d3d7 | 175 | } |
| tyftyftyf | 0:21840c01d3d7 | 176 | } |
| tyftyftyf | 0:21840c01d3d7 | 177 | |
| tyftyftyf | 0:21840c01d3d7 | 178 | /** |
| tyftyftyf | 0:21840c01d3d7 | 179 | * Populates raw_values with the raw_values from the sensors |
| tyftyftyf | 0:21840c01d3d7 | 180 | */ |
| tyftyftyf | 0:21840c01d3d7 | 181 | void FreeIMU::getRawValues(int16_t * raw_values) { |
| tyftyftyf | 0:21840c01d3d7 | 182 | |
| tyftyftyf | 0:21840c01d3d7 | 183 | accgyro.getMotion6(&raw_values[0], &raw_values[1], &raw_values[2], &raw_values[3], &raw_values[4], &raw_values[5]); |
| tyftyftyf | 0:21840c01d3d7 | 184 | magn.getValues(&raw_values[6], &raw_values[7], &raw_values[8]); |
| tyftyftyf | 0:21840c01d3d7 | 185 | |
| tyftyftyf | 0:21840c01d3d7 | 186 | int temp, press; |
| tyftyftyf | 0:21840c01d3d7 | 187 | //TODO: possible loss of precision |
| tyftyftyf | 0:21840c01d3d7 | 188 | temp = baro.rawTemperature(MS561101BA_OSR_4096); |
| tyftyftyf | 0:21840c01d3d7 | 189 | raw_values[9] = temp; |
| tyftyftyf | 0:21840c01d3d7 | 190 | press = baro.rawPressure(MS561101BA_OSR_4096); |
| tyftyftyf | 0:21840c01d3d7 | 191 | raw_values[10] = press; |
| tyftyftyf | 0:21840c01d3d7 | 192 | } |
| tyftyftyf | 0:21840c01d3d7 | 193 | |
| tyftyftyf | 0:21840c01d3d7 | 194 | |
| tyftyftyf | 0:21840c01d3d7 | 195 | /** |
| tyftyftyf | 0:21840c01d3d7 | 196 | * Populates values with calibrated readings from the sensors |
| tyftyftyf | 0:21840c01d3d7 | 197 | */ |
| tyftyftyf | 0:21840c01d3d7 | 198 | void FreeIMU::getValues(float * values) { |
| tyftyftyf | 0:21840c01d3d7 | 199 | |
| tyftyftyf | 0:21840c01d3d7 | 200 | // MPU6050 |
| tyftyftyf | 0:21840c01d3d7 | 201 | int16_t accgyroval[6]; |
| tyftyftyf | 0:21840c01d3d7 | 202 | accgyro.getMotion6(&accgyroval[0], &accgyroval[1], &accgyroval[2], &accgyroval[3], &accgyroval[4], &accgyroval[5]); |
| tyftyftyf | 0:21840c01d3d7 | 203 | |
| tyftyftyf | 0:21840c01d3d7 | 204 | // remove offsets from the gyroscope |
| tyftyftyf | 0:21840c01d3d7 | 205 | accgyroval[3] = accgyroval[3] - gyro_off_x; |
| tyftyftyf | 0:21840c01d3d7 | 206 | accgyroval[4] = accgyroval[4] - gyro_off_y; |
| tyftyftyf | 0:21840c01d3d7 | 207 | accgyroval[5] = accgyroval[5] - gyro_off_z; |
| tyftyftyf | 0:21840c01d3d7 | 208 | |
| tyftyftyf | 0:21840c01d3d7 | 209 | for(int i = 0; i<6; i++) { |
| tyftyftyf | 0:21840c01d3d7 | 210 | if(i < 3) { |
| tyftyftyf | 0:21840c01d3d7 | 211 | values[i] = (float) accgyroval[i]; |
| tyftyftyf | 0:21840c01d3d7 | 212 | } |
| tyftyftyf | 0:21840c01d3d7 | 213 | else { |
| tyftyftyf | 1:794e9cdbc2a0 | 214 | values[i] = ((float) accgyroval[i]) / 32.8f; // NOTE: this depends on the sensitivity chosen |
| tyftyftyf | 0:21840c01d3d7 | 215 | } |
| tyftyftyf | 0:21840c01d3d7 | 216 | } |
| tyftyftyf | 0:21840c01d3d7 | 217 | |
| tyftyftyf | 0:21840c01d3d7 | 218 | |
| tyftyftyf | 0:21840c01d3d7 | 219 | |
| tyftyftyf | 0:21840c01d3d7 | 220 | #warning Accelerometer calibration active: have you calibrated your device? |
| tyftyftyf | 0:21840c01d3d7 | 221 | // remove offsets and scale accelerometer (calibration) |
| tyftyftyf | 0:21840c01d3d7 | 222 | values[0] = (values[0] - acc_off_x) / acc_scale_x; |
| tyftyftyf | 0:21840c01d3d7 | 223 | values[1] = (values[1] - acc_off_y) / acc_scale_y; |
| tyftyftyf | 0:21840c01d3d7 | 224 | values[2] = (values[2] - acc_off_z) / acc_scale_z; |
| tyftyftyf | 0:21840c01d3d7 | 225 | |
| tyftyftyf | 0:21840c01d3d7 | 226 | magn.getValues(&values[6]); |
| tyftyftyf | 0:21840c01d3d7 | 227 | // calibration |
| tyftyftyf | 0:21840c01d3d7 | 228 | #warning Magnetometer calibration active: have you calibrated your device? |
| tyftyftyf | 0:21840c01d3d7 | 229 | values[6] = (values[6] - magn_off_x) / magn_scale_x; |
| tyftyftyf | 0:21840c01d3d7 | 230 | values[7] = (values[7] - magn_off_y) / magn_scale_y; |
| tyftyftyf | 0:21840c01d3d7 | 231 | values[8] = (values[8] - magn_off_z) / magn_scale_z; |
| tyftyftyf | 0:21840c01d3d7 | 232 | |
| tyftyftyf | 0:21840c01d3d7 | 233 | } |
| tyftyftyf | 0:21840c01d3d7 | 234 | |
| tyftyftyf | 0:21840c01d3d7 | 235 | |
| tyftyftyf | 0:21840c01d3d7 | 236 | /** |
| tyftyftyf | 0:21840c01d3d7 | 237 | * Computes gyro offsets |
| tyftyftyf | 0:21840c01d3d7 | 238 | */ |
| tyftyftyf | 0:21840c01d3d7 | 239 | void FreeIMU::zeroGyro() { |
| tyftyftyf | 0:21840c01d3d7 | 240 | const int totSamples = 3; |
| tyftyftyf | 0:21840c01d3d7 | 241 | int16_t raw[11]; |
| tyftyftyf | 0:21840c01d3d7 | 242 | float tmpOffsets[] = {0,0,0}; |
| tyftyftyf | 0:21840c01d3d7 | 243 | |
| tyftyftyf | 0:21840c01d3d7 | 244 | for (int i = 0; i < totSamples; i++){ |
| tyftyftyf | 0:21840c01d3d7 | 245 | getRawValues(raw); |
| tyftyftyf | 0:21840c01d3d7 | 246 | tmpOffsets[0] += raw[3]; |
| tyftyftyf | 0:21840c01d3d7 | 247 | tmpOffsets[1] += raw[4]; |
| tyftyftyf | 0:21840c01d3d7 | 248 | tmpOffsets[2] += raw[5]; |
| tyftyftyf | 0:21840c01d3d7 | 249 | } |
| tyftyftyf | 0:21840c01d3d7 | 250 | |
| tyftyftyf | 0:21840c01d3d7 | 251 | gyro_off_x = tmpOffsets[0] / totSamples; |
| tyftyftyf | 0:21840c01d3d7 | 252 | gyro_off_y = tmpOffsets[1] / totSamples; |
| tyftyftyf | 0:21840c01d3d7 | 253 | gyro_off_z = tmpOffsets[2] / totSamples; |
| tyftyftyf | 0:21840c01d3d7 | 254 | } |
| tyftyftyf | 0:21840c01d3d7 | 255 | |
| tyftyftyf | 0:21840c01d3d7 | 256 | |
| tyftyftyf | 0:21840c01d3d7 | 257 | /** |
| tyftyftyf | 0:21840c01d3d7 | 258 | * Quaternion implementation of the 'DCM filter' [Mayhony et al]. Incorporates the magnetic distortion |
| tyftyftyf | 0:21840c01d3d7 | 259 | * compensation algorithms from Sebastian Madgwick's filter which eliminates the need for a reference |
| tyftyftyf | 0:21840c01d3d7 | 260 | * direction of flux (bx bz) to be predefined and limits the effect of magnetic distortions to yaw |
| tyftyftyf | 0:21840c01d3d7 | 261 | * axis only. |
| tyftyftyf | 0:21840c01d3d7 | 262 | * |
| tyftyftyf | 0:21840c01d3d7 | 263 | * @see: http://www.x-io.co.uk/node/8#open_source_ahrs_and_imu_algorithms |
| tyftyftyf | 0:21840c01d3d7 | 264 | */ |
| tyftyftyf | 0:21840c01d3d7 | 265 | |
| tyftyftyf | 0:21840c01d3d7 | 266 | void FreeIMU::AHRSupdate(float gx, float gy, float gz, float ax, float ay, float az, float mx, float my, float mz) { |
| tyftyftyf | 0:21840c01d3d7 | 267 | |
| tyftyftyf | 0:21840c01d3d7 | 268 | float recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 269 | float q0q0, q0q1, q0q2, q0q3, q1q1, q1q2, q1q3, q2q2, q2q3, q3q3; |
| tyftyftyf | 0:21840c01d3d7 | 270 | float halfex = 0.0f, halfey = 0.0f, halfez = 0.0f; |
| tyftyftyf | 0:21840c01d3d7 | 271 | float qa, qb, qc; |
| tyftyftyf | 0:21840c01d3d7 | 272 | |
| tyftyftyf | 0:21840c01d3d7 | 273 | // Auxiliary variables to avoid repeated arithmetic |
| tyftyftyf | 0:21840c01d3d7 | 274 | q0q0 = q0 * q0; |
| tyftyftyf | 0:21840c01d3d7 | 275 | q0q1 = q0 * q1; |
| tyftyftyf | 0:21840c01d3d7 | 276 | q0q2 = q0 * q2; |
| tyftyftyf | 0:21840c01d3d7 | 277 | q0q3 = q0 * q3; |
| tyftyftyf | 0:21840c01d3d7 | 278 | q1q1 = q1 * q1; |
| tyftyftyf | 0:21840c01d3d7 | 279 | q1q2 = q1 * q2; |
| tyftyftyf | 0:21840c01d3d7 | 280 | q1q3 = q1 * q3; |
| tyftyftyf | 0:21840c01d3d7 | 281 | q2q2 = q2 * q2; |
| tyftyftyf | 0:21840c01d3d7 | 282 | q2q3 = q2 * q3; |
| tyftyftyf | 0:21840c01d3d7 | 283 | q3q3 = q3 * q3; |
| tyftyftyf | 0:21840c01d3d7 | 284 | |
| tyftyftyf | 0:21840c01d3d7 | 285 | // Use magnetometer measurement only when valid (avoids NaN in magnetometer normalisation) |
| tyftyftyf | 0:21840c01d3d7 | 286 | if((mx != 0.0f) && (my != 0.0f) && (mz != 0.0f)) { |
| tyftyftyf | 0:21840c01d3d7 | 287 | float hx, hy, bx, bz; |
| tyftyftyf | 0:21840c01d3d7 | 288 | float halfwx, halfwy, halfwz; |
| tyftyftyf | 0:21840c01d3d7 | 289 | |
| tyftyftyf | 0:21840c01d3d7 | 290 | // Normalise magnetometer measurement |
| tyftyftyf | 0:21840c01d3d7 | 291 | recipNorm = invSqrt(mx * mx + my * my + mz * mz); |
| tyftyftyf | 0:21840c01d3d7 | 292 | mx *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 293 | my *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 294 | mz *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 295 | |
| tyftyftyf | 0:21840c01d3d7 | 296 | // Reference direction of Earth's magnetic field |
| tyftyftyf | 0:21840c01d3d7 | 297 | hx = 2.0f * (mx * (0.5f - q2q2 - q3q3) + my * (q1q2 - q0q3) + mz * (q1q3 + q0q2)); |
| tyftyftyf | 0:21840c01d3d7 | 298 | hy = 2.0f * (mx * (q1q2 + q0q3) + my * (0.5f - q1q1 - q3q3) + mz * (q2q3 - q0q1)); |
| tyftyftyf | 0:21840c01d3d7 | 299 | bx = sqrt(hx * hx + hy * hy); |
| tyftyftyf | 0:21840c01d3d7 | 300 | bz = 2.0f * (mx * (q1q3 - q0q2) + my * (q2q3 + q0q1) + mz * (0.5f - q1q1 - q2q2)); |
| tyftyftyf | 0:21840c01d3d7 | 301 | |
| tyftyftyf | 0:21840c01d3d7 | 302 | // Estimated direction of magnetic field |
| tyftyftyf | 0:21840c01d3d7 | 303 | halfwx = bx * (0.5f - q2q2 - q3q3) + bz * (q1q3 - q0q2); |
| tyftyftyf | 0:21840c01d3d7 | 304 | halfwy = bx * (q1q2 - q0q3) + bz * (q0q1 + q2q3); |
| tyftyftyf | 0:21840c01d3d7 | 305 | halfwz = bx * (q0q2 + q1q3) + bz * (0.5f - q1q1 - q2q2); |
| tyftyftyf | 0:21840c01d3d7 | 306 | |
| tyftyftyf | 0:21840c01d3d7 | 307 | // Error is sum of cross product between estimated direction and measured direction of field vectors |
| tyftyftyf | 0:21840c01d3d7 | 308 | halfex = (my * halfwz - mz * halfwy); |
| tyftyftyf | 0:21840c01d3d7 | 309 | halfey = (mz * halfwx - mx * halfwz); |
| tyftyftyf | 0:21840c01d3d7 | 310 | halfez = (mx * halfwy - my * halfwx); |
| tyftyftyf | 0:21840c01d3d7 | 311 | } |
| tyftyftyf | 0:21840c01d3d7 | 312 | |
| tyftyftyf | 0:21840c01d3d7 | 313 | // Compute feedback only if accelerometer measurement valid (avoids NaN in accelerometer normalisation) |
| tyftyftyf | 0:21840c01d3d7 | 314 | if((ax != 0.0f) && (ay != 0.0f) && (az != 0.0f)) { |
| tyftyftyf | 0:21840c01d3d7 | 315 | float halfvx, halfvy, halfvz; |
| tyftyftyf | 0:21840c01d3d7 | 316 | |
| tyftyftyf | 0:21840c01d3d7 | 317 | // Normalise accelerometer measurement |
| tyftyftyf | 0:21840c01d3d7 | 318 | recipNorm = invSqrt(ax * ax + ay * ay + az * az); |
| tyftyftyf | 0:21840c01d3d7 | 319 | ax *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 320 | ay *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 321 | az *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 322 | |
| tyftyftyf | 0:21840c01d3d7 | 323 | // Estimated direction of gravity |
| tyftyftyf | 0:21840c01d3d7 | 324 | halfvx = q1q3 - q0q2; |
| tyftyftyf | 0:21840c01d3d7 | 325 | halfvy = q0q1 + q2q3; |
| tyftyftyf | 0:21840c01d3d7 | 326 | halfvz = q0q0 - 0.5f + q3q3; |
| tyftyftyf | 0:21840c01d3d7 | 327 | |
| tyftyftyf | 0:21840c01d3d7 | 328 | // Error is sum of cross product between estimated direction and measured direction of field vectors |
| tyftyftyf | 0:21840c01d3d7 | 329 | halfex += (ay * halfvz - az * halfvy); |
| tyftyftyf | 0:21840c01d3d7 | 330 | halfey += (az * halfvx - ax * halfvz); |
| tyftyftyf | 0:21840c01d3d7 | 331 | halfez += (ax * halfvy - ay * halfvx); |
| tyftyftyf | 0:21840c01d3d7 | 332 | } |
| tyftyftyf | 0:21840c01d3d7 | 333 | |
| tyftyftyf | 0:21840c01d3d7 | 334 | // Apply feedback only when valid data has been gathered from the accelerometer or magnetometer |
| tyftyftyf | 0:21840c01d3d7 | 335 | if(halfex != 0.0f && halfey != 0.0f && halfez != 0.0f) { |
| tyftyftyf | 0:21840c01d3d7 | 336 | // Compute and apply integral feedback if enabled |
| tyftyftyf | 0:21840c01d3d7 | 337 | if(twoKi > 0.0f) { |
| tyftyftyf | 0:21840c01d3d7 | 338 | integralFBx += twoKi * halfex * (1.0f / sampleFreq); // integral error scaled by Ki |
| tyftyftyf | 0:21840c01d3d7 | 339 | integralFBy += twoKi * halfey * (1.0f / sampleFreq); |
| tyftyftyf | 0:21840c01d3d7 | 340 | integralFBz += twoKi * halfez * (1.0f / sampleFreq); |
| tyftyftyf | 0:21840c01d3d7 | 341 | gx += integralFBx; // apply integral feedback |
| tyftyftyf | 0:21840c01d3d7 | 342 | gy += integralFBy; |
| tyftyftyf | 0:21840c01d3d7 | 343 | gz += integralFBz; |
| tyftyftyf | 0:21840c01d3d7 | 344 | } |
| tyftyftyf | 0:21840c01d3d7 | 345 | else { |
| tyftyftyf | 0:21840c01d3d7 | 346 | integralFBx = 0.0f; // prevent integral windup |
| tyftyftyf | 0:21840c01d3d7 | 347 | integralFBy = 0.0f; |
| tyftyftyf | 0:21840c01d3d7 | 348 | integralFBz = 0.0f; |
| tyftyftyf | 0:21840c01d3d7 | 349 | } |
| tyftyftyf | 0:21840c01d3d7 | 350 | |
| tyftyftyf | 0:21840c01d3d7 | 351 | // Apply proportional feedback |
| tyftyftyf | 0:21840c01d3d7 | 352 | gx += twoKp * halfex; |
| tyftyftyf | 0:21840c01d3d7 | 353 | gy += twoKp * halfey; |
| tyftyftyf | 0:21840c01d3d7 | 354 | gz += twoKp * halfez; |
| tyftyftyf | 0:21840c01d3d7 | 355 | } |
| tyftyftyf | 0:21840c01d3d7 | 356 | |
| tyftyftyf | 0:21840c01d3d7 | 357 | // Integrate rate of change of quaternion |
| tyftyftyf | 0:21840c01d3d7 | 358 | gx *= (0.5f * (1.0f / sampleFreq)); // pre-multiply common factors |
| tyftyftyf | 0:21840c01d3d7 | 359 | gy *= (0.5f * (1.0f / sampleFreq)); |
| tyftyftyf | 0:21840c01d3d7 | 360 | gz *= (0.5f * (1.0f / sampleFreq)); |
| tyftyftyf | 0:21840c01d3d7 | 361 | qa = q0; |
| tyftyftyf | 0:21840c01d3d7 | 362 | qb = q1; |
| tyftyftyf | 0:21840c01d3d7 | 363 | qc = q2; |
| tyftyftyf | 0:21840c01d3d7 | 364 | q0 += (-qb * gx - qc * gy - q3 * gz); |
| tyftyftyf | 0:21840c01d3d7 | 365 | q1 += (qa * gx + qc * gz - q3 * gy); |
| tyftyftyf | 0:21840c01d3d7 | 366 | q2 += (qa * gy - qb * gz + q3 * gx); |
| tyftyftyf | 0:21840c01d3d7 | 367 | q3 += (qa * gz + qb * gy - qc * gx); |
| tyftyftyf | 0:21840c01d3d7 | 368 | |
| tyftyftyf | 0:21840c01d3d7 | 369 | // Normalise quaternion |
| tyftyftyf | 0:21840c01d3d7 | 370 | recipNorm = invSqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3); |
| tyftyftyf | 0:21840c01d3d7 | 371 | q0 *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 372 | q1 *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 373 | q2 *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 374 | q3 *= recipNorm; |
| tyftyftyf | 0:21840c01d3d7 | 375 | } |
| tyftyftyf | 0:21840c01d3d7 | 376 | |
| tyftyftyf | 0:21840c01d3d7 | 377 | |
| tyftyftyf | 0:21840c01d3d7 | 378 | /** |
| tyftyftyf | 0:21840c01d3d7 | 379 | * Populates array q with a quaternion representing the IMU orientation with respect to the Earth |
| tyftyftyf | 0:21840c01d3d7 | 380 | * |
| tyftyftyf | 0:21840c01d3d7 | 381 | * @param q the quaternion to populate |
| tyftyftyf | 0:21840c01d3d7 | 382 | */ |
| tyftyftyf | 0:21840c01d3d7 | 383 | void FreeIMU::getQ(float * q) { |
| tyftyftyf | 0:21840c01d3d7 | 384 | float val[9]; |
| tyftyftyf | 0:21840c01d3d7 | 385 | getValues(val); |
| tyftyftyf | 0:21840c01d3d7 | 386 | |
| tyftyftyf | 0:21840c01d3d7 | 387 | DEBUG_PRINT(val[3] * M_PI/180); |
| tyftyftyf | 0:21840c01d3d7 | 388 | DEBUG_PRINT(val[4] * M_PI/180); |
| tyftyftyf | 0:21840c01d3d7 | 389 | DEBUG_PRINT(val[5] * M_PI/180); |
| tyftyftyf | 0:21840c01d3d7 | 390 | DEBUG_PRINT(val[0]); |
| tyftyftyf | 0:21840c01d3d7 | 391 | DEBUG_PRINT(val[1]); |
| tyftyftyf | 0:21840c01d3d7 | 392 | DEBUG_PRINT(val[2]); |
| tyftyftyf | 0:21840c01d3d7 | 393 | DEBUG_PRINT(val[6]); |
| tyftyftyf | 0:21840c01d3d7 | 394 | DEBUG_PRINT(val[7]); |
| tyftyftyf | 0:21840c01d3d7 | 395 | DEBUG_PRINT(val[8]); |
| tyftyftyf | 0:21840c01d3d7 | 396 | |
| tyftyftyf | 0:21840c01d3d7 | 397 | //now = micros(); |
| tyftyftyf | 0:21840c01d3d7 | 398 | dt_us=update.read_us(); |
| tyftyftyf | 0:21840c01d3d7 | 399 | sampleFreq = 1.0 / ((dt_us) / 1000000.0); |
| tyftyftyf | 0:21840c01d3d7 | 400 | update.reset(); |
| tyftyftyf | 0:21840c01d3d7 | 401 | // lastUpdate = now; |
| tyftyftyf | 0:21840c01d3d7 | 402 | // gyro values are expressed in deg/sec, the * M_PI/180 will convert it to radians/sec |
| tyftyftyf | 0:21840c01d3d7 | 403 | |
| tyftyftyf | 0:21840c01d3d7 | 404 | AHRSupdate(val[3] * M_PI/180, val[4] * M_PI/180, val[5] * M_PI/180, val[0], val[1], val[2], val[6], val[7], val[8]); |
| tyftyftyf | 0:21840c01d3d7 | 405 | |
| tyftyftyf | 0:21840c01d3d7 | 406 | if (q!=NULL){ |
| tyftyftyf | 0:21840c01d3d7 | 407 | q[0] = q0; |
| tyftyftyf | 0:21840c01d3d7 | 408 | q[1] = q1; |
| tyftyftyf | 0:21840c01d3d7 | 409 | q[2] = q2; |
| tyftyftyf | 0:21840c01d3d7 | 410 | q[3] = q3; |
| tyftyftyf | 0:21840c01d3d7 | 411 | } |
| tyftyftyf | 0:21840c01d3d7 | 412 | } |
| tyftyftyf | 0:21840c01d3d7 | 413 | |
| tyftyftyf | 0:21840c01d3d7 | 414 | |
| tyftyftyf | 0:21840c01d3d7 | 415 | const float def_sea_press = 1013.25; |
| tyftyftyf | 0:21840c01d3d7 | 416 | |
| tyftyftyf | 0:21840c01d3d7 | 417 | /** |
| tyftyftyf | 0:21840c01d3d7 | 418 | * Returns an altitude estimate from baromether readings only using sea_press as current sea level pressure |
| tyftyftyf | 0:21840c01d3d7 | 419 | */ |
| tyftyftyf | 0:21840c01d3d7 | 420 | float FreeIMU::getBaroAlt(float sea_press) { |
| tyftyftyf | 0:21840c01d3d7 | 421 | float temp = baro.getTemperature(MS561101BA_OSR_4096); |
| tyftyftyf | 0:21840c01d3d7 | 422 | float press = baro.getPressure(MS561101BA_OSR_4096); |
| tyftyftyf | 0:21840c01d3d7 | 423 | return ((pow((float)(sea_press / press), 1.0f/5.257f) - 1.0f) * (temp + 273.15f)) / 0.0065f; |
| tyftyftyf | 0:21840c01d3d7 | 424 | } |
| tyftyftyf | 0:21840c01d3d7 | 425 | |
| tyftyftyf | 0:21840c01d3d7 | 426 | /** |
| tyftyftyf | 0:21840c01d3d7 | 427 | * Returns an altitude estimate from baromether readings only using a default sea level pressure |
| tyftyftyf | 0:21840c01d3d7 | 428 | */ |
| tyftyftyf | 0:21840c01d3d7 | 429 | float FreeIMU::getBaroAlt() { |
| tyftyftyf | 0:21840c01d3d7 | 430 | return getBaroAlt(def_sea_press); |
| tyftyftyf | 0:21840c01d3d7 | 431 | } |
| tyftyftyf | 0:21840c01d3d7 | 432 | |
| tyftyftyf | 0:21840c01d3d7 | 433 | float FreeIMU::getRawPressure() { |
| tyftyftyf | 0:21840c01d3d7 | 434 | return baro.getPressure(MS561101BA_OSR_4096); |
| tyftyftyf | 0:21840c01d3d7 | 435 | } |
| tyftyftyf | 0:21840c01d3d7 | 436 | |
| tyftyftyf | 0:21840c01d3d7 | 437 | |
| tyftyftyf | 0:21840c01d3d7 | 438 | /** |
| tyftyftyf | 0:21840c01d3d7 | 439 | * Compensates the accelerometer readings in the 3D vector acc expressed in the sensor frame for gravity |
| tyftyftyf | 0:21840c01d3d7 | 440 | * @param acc the accelerometer readings to compensate for gravity |
| tyftyftyf | 0:21840c01d3d7 | 441 | * @param q the quaternion orientation of the sensor board with respect to the world |
| tyftyftyf | 0:21840c01d3d7 | 442 | */ |
| tyftyftyf | 0:21840c01d3d7 | 443 | void FreeIMU::gravityCompensateAcc(float * acc, float * q) { |
| tyftyftyf | 0:21840c01d3d7 | 444 | float g[3]; |
| tyftyftyf | 0:21840c01d3d7 | 445 | |
| tyftyftyf | 0:21840c01d3d7 | 446 | // get expected direction of gravity in the sensor frame |
| tyftyftyf | 0:21840c01d3d7 | 447 | g[0] = 2 * (q[1] * q[3] - q[0] * q[2]); |
| tyftyftyf | 0:21840c01d3d7 | 448 | g[1] = 2 * (q[0] * q[1] + q[2] * q[3]); |
| tyftyftyf | 0:21840c01d3d7 | 449 | g[2] = q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]; |
| tyftyftyf | 0:21840c01d3d7 | 450 | |
| tyftyftyf | 0:21840c01d3d7 | 451 | // compensate accelerometer readings with the expected direction of gravity |
| tyftyftyf | 0:21840c01d3d7 | 452 | acc[0] = acc[0] - g[0]; |
| tyftyftyf | 0:21840c01d3d7 | 453 | acc[1] = acc[1] - g[1]; |
| tyftyftyf | 0:21840c01d3d7 | 454 | acc[2] = acc[2] - g[2]; |
| tyftyftyf | 0:21840c01d3d7 | 455 | } |
| tyftyftyf | 0:21840c01d3d7 | 456 | |
| tyftyftyf | 0:21840c01d3d7 | 457 | |
| tyftyftyf | 0:21840c01d3d7 | 458 | /** |
| tyftyftyf | 0:21840c01d3d7 | 459 | * Returns the Euler angles in radians defined in the Aerospace sequence. |
| tyftyftyf | 0:21840c01d3d7 | 460 | * See Sebastian O.H. Madwick report "An efficient orientation filter for |
| tyftyftyf | 0:21840c01d3d7 | 461 | * inertial and intertial/magnetic sensor arrays" Chapter 2 Quaternion representation |
| tyftyftyf | 0:21840c01d3d7 | 462 | * |
| tyftyftyf | 0:21840c01d3d7 | 463 | * @param angles three floats array which will be populated by the Euler angles in radians |
| tyftyftyf | 0:21840c01d3d7 | 464 | */ |
| tyftyftyf | 0:21840c01d3d7 | 465 | void FreeIMU::getEulerRad(float * angles) { |
| tyftyftyf | 0:21840c01d3d7 | 466 | float q[4]; // quaternion |
| tyftyftyf | 0:21840c01d3d7 | 467 | getQ(q); |
| tyftyftyf | 0:21840c01d3d7 | 468 | angles[0] = atan2(2 * q[1] * q[2] - 2 * q[0] * q[3], 2 * q[0]*q[0] + 2 * q[1] * q[1] - 1); // psi |
| tyftyftyf | 0:21840c01d3d7 | 469 | angles[1] = -asin(2 * q[1] * q[3] + 2 * q[0] * q[2]); // theta |
| tyftyftyf | 0:21840c01d3d7 | 470 | angles[2] = atan2(2 * q[2] * q[3] - 2 * q[0] * q[1], 2 * q[0] * q[0] + 2 * q[3] * q[3] - 1); // phi |
| tyftyftyf | 0:21840c01d3d7 | 471 | } |
| tyftyftyf | 0:21840c01d3d7 | 472 | |
| tyftyftyf | 0:21840c01d3d7 | 473 | |
| tyftyftyf | 0:21840c01d3d7 | 474 | /** |
| tyftyftyf | 0:21840c01d3d7 | 475 | * Returns the Euler angles in degrees defined with the Aerospace sequence. |
| tyftyftyf | 0:21840c01d3d7 | 476 | * See Sebastian O.H. Madwick report "An efficient orientation filter for |
| tyftyftyf | 0:21840c01d3d7 | 477 | * inertial and intertial/magnetic sensor arrays" Chapter 2 Quaternion representation |
| tyftyftyf | 0:21840c01d3d7 | 478 | * |
| tyftyftyf | 0:21840c01d3d7 | 479 | * @param angles three floats array which will be populated by the Euler angles in degrees |
| tyftyftyf | 0:21840c01d3d7 | 480 | */ |
| tyftyftyf | 0:21840c01d3d7 | 481 | void FreeIMU::getEuler(float * angles) { |
| tyftyftyf | 0:21840c01d3d7 | 482 | getEulerRad(angles); |
| tyftyftyf | 0:21840c01d3d7 | 483 | arr3_rad_to_deg(angles); |
| tyftyftyf | 0:21840c01d3d7 | 484 | } |
| tyftyftyf | 0:21840c01d3d7 | 485 | |
| tyftyftyf | 0:21840c01d3d7 | 486 | |
| tyftyftyf | 0:21840c01d3d7 | 487 | /** |
| tyftyftyf | 0:21840c01d3d7 | 488 | * Returns the yaw pitch and roll angles, respectively defined as the angles in radians between |
| tyftyftyf | 0:21840c01d3d7 | 489 | * the Earth North and the IMU X axis (yaw), the Earth ground plane and the IMU X axis (pitch) |
| tyftyftyf | 0:21840c01d3d7 | 490 | * and the Earth ground plane and the IMU Y axis. |
| tyftyftyf | 0:21840c01d3d7 | 491 | * |
| tyftyftyf | 0:21840c01d3d7 | 492 | * @note This is not an Euler representation: the rotations aren't consecutive rotations but only |
| tyftyftyf | 0:21840c01d3d7 | 493 | * angles from Earth and the IMU. For Euler representation Yaw, Pitch and Roll see FreeIMU::getEuler |
| tyftyftyf | 0:21840c01d3d7 | 494 | * |
| tyftyftyf | 0:21840c01d3d7 | 495 | * @param ypr three floats array which will be populated by Yaw, Pitch and Roll angles in radians |
| tyftyftyf | 0:21840c01d3d7 | 496 | */ |
| tyftyftyf | 0:21840c01d3d7 | 497 | void FreeIMU::getYawPitchRollRad(float * ypr) { |
| tyftyftyf | 0:21840c01d3d7 | 498 | float q[4]; // quaternion |
| tyftyftyf | 0:21840c01d3d7 | 499 | float gx, gy, gz; // estimated gravity direction |
| tyftyftyf | 0:21840c01d3d7 | 500 | getQ(q); |
| tyftyftyf | 0:21840c01d3d7 | 501 | |
| tyftyftyf | 0:21840c01d3d7 | 502 | gx = 2 * (q[1]*q[3] - q[0]*q[2]); |
| tyftyftyf | 0:21840c01d3d7 | 503 | gy = 2 * (q[0]*q[1] + q[2]*q[3]); |
| tyftyftyf | 0:21840c01d3d7 | 504 | gz = q[0]*q[0] - q[1]*q[1] - q[2]*q[2] + q[3]*q[3]; |
| tyftyftyf | 0:21840c01d3d7 | 505 | |
| tyftyftyf | 0:21840c01d3d7 | 506 | ypr[0] = atan2(2 * q[1] * q[2] - 2 * q[0] * q[3], 2 * q[0]*q[0] + 2 * q[1] * q[1] - 1); |
| tyftyftyf | 0:21840c01d3d7 | 507 | ypr[1] = atan(gx / sqrt(gy*gy + gz*gz)); |
| tyftyftyf | 0:21840c01d3d7 | 508 | ypr[2] = atan(gy / sqrt(gx*gx + gz*gz)); |
| tyftyftyf | 0:21840c01d3d7 | 509 | } |
| tyftyftyf | 0:21840c01d3d7 | 510 | |
| tyftyftyf | 0:21840c01d3d7 | 511 | |
| tyftyftyf | 0:21840c01d3d7 | 512 | /** |
| tyftyftyf | 0:21840c01d3d7 | 513 | * Returns the yaw pitch and roll angles, respectively defined as the angles in degrees between |
| tyftyftyf | 0:21840c01d3d7 | 514 | * the Earth North and the IMU X axis (yaw), the Earth ground plane and the IMU X axis (pitch) |
| tyftyftyf | 0:21840c01d3d7 | 515 | * and the Earth ground plane and the IMU Y axis. |
| tyftyftyf | 0:21840c01d3d7 | 516 | * |
| tyftyftyf | 0:21840c01d3d7 | 517 | * @note This is not an Euler representation: the rotations aren't consecutive rotations but only |
| tyftyftyf | 0:21840c01d3d7 | 518 | * angles from Earth and the IMU. For Euler representation Yaw, Pitch and Roll see FreeIMU::getEuler |
| tyftyftyf | 0:21840c01d3d7 | 519 | * |
| tyftyftyf | 0:21840c01d3d7 | 520 | * @param ypr three floats array which will be populated by Yaw, Pitch and Roll angles in degrees |
| tyftyftyf | 0:21840c01d3d7 | 521 | */ |
| tyftyftyf | 0:21840c01d3d7 | 522 | void FreeIMU::getYawPitchRoll(float * ypr) { |
| tyftyftyf | 0:21840c01d3d7 | 523 | getYawPitchRollRad(ypr); |
| tyftyftyf | 0:21840c01d3d7 | 524 | arr3_rad_to_deg(ypr); |
| tyftyftyf | 0:21840c01d3d7 | 525 | } |
| tyftyftyf | 0:21840c01d3d7 | 526 | |
| tyftyftyf | 0:21840c01d3d7 | 527 | |
| tyftyftyf | 0:21840c01d3d7 | 528 | /** |
| tyftyftyf | 0:21840c01d3d7 | 529 | * Converts a 3 elements array arr of angles expressed in radians into degrees |
| tyftyftyf | 0:21840c01d3d7 | 530 | */ |
| tyftyftyf | 0:21840c01d3d7 | 531 | void arr3_rad_to_deg(float * arr) { |
| tyftyftyf | 0:21840c01d3d7 | 532 | arr[0] *= 180/M_PI; |
| tyftyftyf | 0:21840c01d3d7 | 533 | arr[1] *= 180/M_PI; |
| tyftyftyf | 0:21840c01d3d7 | 534 | arr[2] *= 180/M_PI; |
| tyftyftyf | 0:21840c01d3d7 | 535 | } |
| tyftyftyf | 0:21840c01d3d7 | 536 | |
| tyftyftyf | 0:21840c01d3d7 | 537 | |
| tyftyftyf | 0:21840c01d3d7 | 538 | /** |
| tyftyftyf | 0:21840c01d3d7 | 539 | * Fast inverse square root implementation |
| tyftyftyf | 0:21840c01d3d7 | 540 | * @see http://en.wikipedia.org/wiki/Fast_inverse_square_root |
| tyftyftyf | 0:21840c01d3d7 | 541 | */ |
| tyftyftyf | 0:21840c01d3d7 | 542 | float invSqrt(float number) { |
| tyftyftyf | 0:21840c01d3d7 | 543 | volatile long i; |
| tyftyftyf | 0:21840c01d3d7 | 544 | volatile float x, y; |
| tyftyftyf | 0:21840c01d3d7 | 545 | volatile const float f = 1.5F; |
| tyftyftyf | 0:21840c01d3d7 | 546 | |
| tyftyftyf | 0:21840c01d3d7 | 547 | x = number * 0.5F; |
| tyftyftyf | 0:21840c01d3d7 | 548 | y = number; |
| tyftyftyf | 0:21840c01d3d7 | 549 | i = * ( long * ) &y; |
| tyftyftyf | 0:21840c01d3d7 | 550 | i = 0x5f375a86 - ( i >> 1 ); |
| tyftyftyf | 0:21840c01d3d7 | 551 | y = * ( float * ) &i; |
| tyftyftyf | 0:21840c01d3d7 | 552 | y = y * ( f - ( x * y * y ) ); |
| tyftyftyf | 0:21840c01d3d7 | 553 | return y; |
| tyftyftyf | 0:21840c01d3d7 | 554 | } |
| tyftyftyf | 0:21840c01d3d7 | 555 | |
| tyftyftyf | 0:21840c01d3d7 | 556 |