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700 killagreg 1
/*
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741 killagreg 3
Copyright 2008, by Killagreg
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This program (files mm3.c and mm3.h) is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation;
7
either version 3 of the License, or (at your option) any later version.
8
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
9
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10
GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License
11
along with this program. If not, see <http://www.gnu.org/licenses/>.
12
 
741 killagreg 13
Please note: The original implementation was done by Niklas Nold.
14
All the other files for the project "Mikrokopter" by H. Buss are under the license (license_buss.txt) published by www.mikrokopter.de
700 killagreg 15
*/
16
#include <stdlib.h>
17
#include <avr/io.h>
18
#include <avr/interrupt.h>
19
 
20
#include "mm3.h"
21
#include "main.h"
22
#include "mymath.h"
23
#include "fc.h"
24
#include "timer0.h"
25
#include "rc.h"
26
#include "eeprom.h"
790 killagreg 27
#include "printf_P.h"
700 killagreg 28
 
29
#define MAX_AXIS_VALUE          500
30
 
31
 
32
typedef struct
33
{
34
        uint8_t STATE;
35
        uint16_t DRDY;
36
        uint8_t AXIS;
37
        int16_t x_axis;
38
        int16_t y_axis;
39
        int16_t z_axis;
40
} MM3_working_t;
41
 
42
 
43
// MM3 State Machine
44
#define MM3_STATE_RESET                         0
45
#define MM3_STATE_START_TRANSFER        1
46
#define MM3_STATE_WAIT_DRDY                     2
47
#define MM3_STATE_DRDY                          3
48
#define MM3_STATE_BYTE2                         4
49
 
50
#define MM3_X_AXIS              0x01
51
#define MM3_Y_AXIS              0x02
52
#define MM3_Z_AXIS              0x03
53
 
54
 
55
#define MM3_PERIOD_32   0x00
56
#define MM3_PERIOD_64   0x10
57
#define MM3_PERIOD_128  0x20
58
#define MM3_PERIOD_256  0x30
59
#define MM3_PERIOD_512  0x40
60
#define MM3_PERIOD_1024 0x50
61
#define MM3_PERIOD_2048 0x60
62
#define MM3_PERIOD_4096 0x70
63
 
64
MM3_calib_t MM3_calib;
65
volatile MM3_working_t MM3;
754 killagreg 66
volatile uint8_t MM3_Timeout = 0;
700 killagreg 67
 
68
 
69
 
70
/*********************************************/
71
/*  Initialize Interface to MM3 Compass      */
72
/*********************************************/
726 killagreg 73
void MM3_Init(void)
700 killagreg 74
{
75
        uint8_t sreg = SREG;
76
 
77
        cli();
78
 
79
        // Configure Pins for SPI
80
        // set SCK (PB7), MOSI (PB5) as output
81
        DDRB |= (1<<DDB7)|(1<<DDB5);
82
        // set MISO (PB6) as input
83
        DDRB &= ~(1<<DDB6);
84
 
781 killagreg 85
#ifdef USE_WALTER_EXT // walthers board
86
        // Output Pins (J9)PC6->MM3_SS ,(J8)PB2->MM3_RESET
87
        DDRB |= (1<<DDB2);
88
        DDRC |= (1<<DDC6);
89
        // set pins permanent to low
90
        PORTB &= ~((1<<PORTB2));
91
        PORTC &= ~((1<<PORTC6));
92
#else // killagregs board
700 killagreg 93
        // Output Pins PC4->MM3_SS ,PC5->MM3_RESET
94
        DDRC |= (1<<DDC4)|(1<<DDC5);
95
        // set pins permanent to low
96
        PORTC &= ~((1<<PORTC4)|(1<<PORTC5));
781 killagreg 97
#endif
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99
        // Initialize SPI-Interface
100
        // Enable interrupt (SPIE=1)
101
        // Enable SPI bus (SPE=1)
102
        // MSB transmitted first (DORD = 0)
103
        // Master SPI Mode (MSTR=1)
781 killagreg 104
        // Clock polarity low when idle (CPOL=0)
105
        // Clock phase sample at leading edge (CPHA=0)
106
        // Clock rate = SYSCLK/128 (SPI2X=0, SPR1=1, SPR0=1) 20MHz/128 = 156.25kHz
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        SPCR = (1<<SPIE)|(1<<SPE)|(0<<DORD)|(1<<MSTR)|(0<<CPOL)|(0<<CPHA)|(1<<SPR1)|(1<<SPR0);
108
        SPSR &= ~(1<<SPI2X);
109
 
110
    // Init Statemachine
111
        MM3.AXIS = MM3_X_AXIS;
112
        MM3.STATE = MM3_STATE_RESET;
113
 
114
        // Read calibration from EEprom
115
        MM3_calib.X_off = (int8_t)GetParamByte(PID_MM3_X_OFF);
116
        MM3_calib.Y_off = (int8_t)GetParamByte(PID_MM3_Y_OFF);
117
        MM3_calib.Z_off = (int8_t)GetParamByte(PID_MM3_Z_OFF);
118
        MM3_calib.X_range = (int16_t)GetParamWord(PID_MM3_X_RANGE);
119
        MM3_calib.Y_range = (int16_t)GetParamWord(PID_MM3_Y_RANGE);
120
        MM3_calib.Z_range = (int16_t)GetParamWord(PID_MM3_Z_RANGE);
121
 
741 killagreg 122
        MM3_Timeout = 0;
123
 
700 killagreg 124
        SREG = sreg;
125
}
126
 
127
 
128
/*********************************************/
129
/*  Get Data from MM3                        */
130
/*********************************************/
754 killagreg 131
void MM3_Update(void) // called every 102.4 µs by timer 0 ISR
700 killagreg 132
{
133
        switch (MM3.STATE)
134
        {
135
        case MM3_STATE_RESET:
781 killagreg 136
                #ifdef USE_WALTER_EXT // walthers board
137
                PORTC &= ~(1<<PORTC6);  // select slave
138
                PORTB |= (1<<PORTB2);   // PB2 to High, MM3 Reset
139
                #else
741 killagreg 140
                PORTC &= ~(1<<PORTC4);  // select slave
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                PORTC |= (1<<PORTC5);   // PC5 to High, MM3 Reset
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                #endif
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                MM3.STATE = MM3_STATE_START_TRANSFER;
144
                return;
145
 
146
        case MM3_STATE_START_TRANSFER:
781 killagreg 147
                #ifdef USE_WALTER_EXT // walthers board
148
                PORTB &= ~(1<<PORTB2);  // PB2 auf Low (was 102.4 µs at high level)
149
                #else
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                PORTC &= ~(1<<PORTC5);  // PC4 auf Low (was 102.4 µs at high level)
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                #endif
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                // write to SPDR triggers automatically the transfer MOSI MISO
153
                // MM3 Period, + AXIS code
741 killagreg 154
                switch(MM3.AXIS)
155
                {
156
                case MM3_X_AXIS:
157
                        SPDR = MM3_PERIOD_256 + MM3_X_AXIS;
158
                        break;
159
                case MM3_Y_AXIS:
160
                        SPDR = MM3_PERIOD_256 + MM3_Y_AXIS;
161
                        break;
162
                case MM3_Z_AXIS:
163
                        SPDR = MM3_PERIOD_256 + MM3_Z_AXIS;
164
                        break;
165
                default:
166
                        MM3.AXIS = MM3_X_AXIS;
167
                        MM3.STATE = MM3_STATE_RESET;
168
                        return;
169
                }
700 killagreg 170
 
171
                // DRDY line is not connected, therefore
172
                // wait before reading data back
173
                MM3.DRDY = SetDelay(8); // wait 8ms for data ready
174
                MM3.STATE = MM3_STATE_WAIT_DRDY;
175
                return;
176
 
177
        case MM3_STATE_WAIT_DRDY:
178
                if (CheckDelay(MM3.DRDY))
179
                {
180
                        // write something into SPDR to trigger data reading
181
                        SPDR = 0x00;
182
                        MM3.STATE = MM3_STATE_DRDY;
183
                }
184
                return;
185
        }
186
}
187
 
188
 
189
/*********************************************/
190
/*  Interrupt SPI transfer complete          */
191
/*********************************************/
192
ISR(SPI_STC_vect)
193
{
194
        static int8_t tmp;
195
        int16_t value;
196
 
197
        switch (MM3.STATE)
198
        {
199
        // 1st byte received
200
        case MM3_STATE_DRDY:
201
                tmp = SPDR;     // store 1st byte
202
                SPDR = 0x00;    // trigger transfer of 2nd byte
203
                MM3.STATE = MM3_STATE_BYTE2;
204
                return;
205
 
206
        case MM3_STATE_BYTE2:           // 2nd byte received
207
                value = (int16_t)tmp;   // combine the 1st and 2nd byte to a word
208
                value <<= 8;            // shift 1st byte to MSB-Position
209
                value |= (int16_t)SPDR; // add 2nd byte
210
 
211
                if(abs(value) < MAX_AXIS_VALUE)         // ignore spikes
212
                {
213
                        switch (MM3.AXIS)
214
                        {
215
                        case MM3_X_AXIS:
216
                                MM3.x_axis = value;
217
                                MM3.AXIS = MM3_Y_AXIS;
218
                                break;
219
                        case MM3_Y_AXIS:
220
                                MM3.y_axis = value;
221
                                MM3.AXIS = MM3_Z_AXIS;
222
                                break;
223
                        case MM3_Z_AXIS:
224
                                MM3.z_axis = value;
225
                                MM3.AXIS = MM3_X_AXIS;
226
                                break;
227
                        default:
228
                                MM3.AXIS = MM3_X_AXIS;
229
                                break;
230
                        }
231
                }
781 killagreg 232
                #ifdef USE_WALTER_EXT // walthers board
233
                PORTC |= (1<<PORTC6); // deselect slave
234
                #else
727 killagreg 235
                PORTC |= (1<<PORTC4); // deselect slave
781 killagreg 236
                #endif
700 killagreg 237
                MM3.STATE = MM3_STATE_RESET;
741 killagreg 238
                // Update timeout is called every 102.4 µs.
239
                // It takes 2 cycles to write a measurement data request for one axis and
240
                // at at least 8 ms / 102.4 µs = 79 cycles to read the requested data back.
241
                // I.e. 81 cycles * 102.4 µs = 8.3ms per axis.
242
                // The two function accessing the MM3 Data - MM3_Calibrate() and MM3_Heading() -
243
                // decremtent the MM3_Timeout every 100 ms.
244
                // incrementing the counter by 1 every 8.3 ms is sufficient to avoid a timeout.
245
                if ((MM3.x_axis != MM3.y_axis) || (MM3.x_axis != MM3.z_axis) || (MM3.y_axis != MM3.z_axis))
246
                {       // if all axis measurements give diffrent readings the data should be valid
247
                        if(MM3_Timeout < 20) MM3_Timeout++;
248
                }
249
                else // something is very strange here
250
                {
251
                        if(MM3_Timeout ) MM3_Timeout--;
252
                }
253
                return;
254
 
255
        default:
256
                return;
700 killagreg 257
        }
258
}
259
 
260
 
261
 
262
/*********************************************/
263
/*  Calibrate Compass                        */
264
/*********************************************/
726 killagreg 265
void MM3_Calibrate(void)
700 killagreg 266
{
790 killagreg 267
        static uint8_t debugcounter = 0;
700 killagreg 268
        int16_t x_min = 0, x_max = 0, y_min = 0, y_max = 0, z_min = 0, z_max = 0;
269
        uint8_t measurement = 50, beeper = 0;
270
        uint16_t timer;
271
 
272
        GRN_ON;
273
        ROT_OFF;
274
 
275
        // get maximum and minimum reading of all axis
773 killagreg 276
        while (measurement)
700 killagreg 277
        {
790 killagreg 278
                // reset range markers if yawstick ist leftmost
279
                if(PPM_in[ParamSet.ChannelAssignment[CH_YAW]] > 100)
280
                {
281
                        x_min = 0;
282
                        x_max = 0;
283
                        y_min = 0;
284
                        y_max = 0;
285
                        z_min = 0;
286
                        z_max = 0;
287
                }
288
 
700 killagreg 289
                if (MM3.x_axis > x_max) x_max = MM3.x_axis;
290
                else if (MM3.x_axis < x_min) x_min = MM3.x_axis;
291
 
292
                if (MM3.y_axis > y_max) y_max = MM3.y_axis;
293
                else if (MM3.y_axis < y_min) y_min = MM3.y_axis;
294
 
295
                if (MM3.z_axis > z_max) z_max = MM3.z_axis;
296
                else if (MM3.z_axis < z_min) z_min = MM3.z_axis;
297
 
298
                if (!beeper)
299
                {
300
                        ROT_FLASH;
301
                        GRN_FLASH;
302
                        BeepTime = 50;
303
                        beeper = 50;
304
                }
305
                beeper--;
306
                // loop with period of 10 ms / 100 Hz
307
                timer = SetDelay(10);
308
                while(!CheckDelay(timer));
309
 
790 killagreg 310
                if(debugcounter++ > 30)
311
                {
312
                        printf("\n\rXMin:%4d, XMax:%4d, YMin:%4d, YMax:%4d, ZMin:%4d, ZMax:%4d",x_min,x_max,y_min,y_max,z_min,z_max);
313
                        debugcounter = 0;
314
                }
315
 
707 killagreg 316
                // If thrust is less than 100, stop calibration with a delay of 0.5 seconds
317
                if (PPM_in[ParamSet.ChannelAssignment[CH_THRUST]] < 100) measurement--;
700 killagreg 318
        }
773 killagreg 319
        // Rage of all axis
320
        MM3_calib.X_range = (x_max - x_min);
321
        MM3_calib.Y_range = (y_max - y_min);
322
        MM3_calib.Z_range = (z_max - z_min);
700 killagreg 323
 
773 killagreg 324
        // Offset of all axis
325
        MM3_calib.X_off = (x_max + x_min) / 2;
326
        MM3_calib.Y_off = (y_max + y_min) / 2;
327
        MM3_calib.Z_off = (z_max + z_min) / 2;
700 killagreg 328
 
773 killagreg 329
        // save to EEProm
330
        SetParamByte(PID_MM3_X_OFF,   (uint8_t)MM3_calib.X_off);
331
        SetParamByte(PID_MM3_Y_OFF,   (uint8_t)MM3_calib.Y_off);
332
        SetParamByte(PID_MM3_Z_OFF,   (uint8_t)MM3_calib.Z_off);
333
        SetParamWord(PID_MM3_X_RANGE, (uint16_t)MM3_calib.X_range);
334
        SetParamWord(PID_MM3_Y_RANGE, (uint16_t)MM3_calib.Y_range);
335
        SetParamWord(PID_MM3_Z_RANGE, (uint16_t)MM3_calib.Z_range);
336
 
700 killagreg 337
}
338
 
339
 
340
/*********************************************/
341
/*  Calculate north direction (heading)      */
342
/*********************************************/
726 killagreg 343
int16_t MM3_Heading(void)
700 killagreg 344
{
701 killagreg 345
        int32_t sin_pitch, cos_pitch, sin_roll, cos_roll, sin_yaw, cos_yaw;
700 killagreg 346
        int32_t  Hx, Hy, Hz, Hx_corr, Hy_corr;
347
        int16_t angle;
348
        uint16_t div_factor;
349
        int16_t heading;
350
 
741 killagreg 351
        if (MM3_Timeout)
352
        {
353
                // Offset correction and normalization (values of H are +/- 512)
354
                Hx = (((int32_t)(MM3.x_axis - MM3_calib.X_off)) * 1024) / (int32_t)MM3_calib.X_range;
355
                Hy = (((int32_t)(MM3.y_axis - MM3_calib.Y_off)) * 1024) / (int32_t)MM3_calib.Y_range;
356
                Hz = (((int32_t)(MM3.z_axis - MM3_calib.Z_off)) * 1024) / (int32_t)MM3_calib.Z_range;
700 killagreg 357
 
741 killagreg 358
                // Compensate the angle of the MM3-arrow to the head of the MK by a yaw rotation transformation
359
                // assuming the MM3 board is mounted parallel to the frame.
360
                // User Param 4 is used to define the positive angle from the MM3-arrow to the MK heading
361
                // in a top view counter clockwise direction.
362
                // North is in opposite direction of the small arrow on the MM3 board.
363
                // Therefore 180 deg must be added to that angle.
364
                angle = ((int16_t)ParamSet.UserParam4 + 180);
365
                // wrap angle to interval of 0°- 359°
366
                angle += 360;
367
                angle %= 360;
368
                sin_yaw = (int32_t)(c_sin_8192(angle));
369
                cos_yaw = (int32_t)(c_cos_8192(angle));
700 killagreg 370
 
741 killagreg 371
                Hx_corr = Hx;
372
                Hy_corr = Hy;
700 killagreg 373
 
741 killagreg 374
                // rotate
375
                Hx = (Hx_corr * cos_yaw - Hy_corr  * sin_yaw) / 8192;
376
                Hy = (Hx_corr * sin_yaw + Hy_corr  * cos_yaw) / 8192;
700 killagreg 377
 
378
 
741 killagreg 379
                // tilt compensation
700 killagreg 380
 
741 killagreg 381
                // calibration factor for transforming Gyro Integrals to angular degrees
382
                div_factor = (uint16_t)ParamSet.UserParam3 * 8;
700 killagreg 383
 
741 killagreg 384
                // calculate sinus cosinus of pitch and tilt angle
385
                angle = (IntegralPitch/div_factor);
386
                sin_pitch = (int32_t)(c_sin_8192(angle));
387
                cos_pitch = (int32_t)(c_cos_8192(angle));
700 killagreg 388
 
741 killagreg 389
                angle = (IntegralRoll/div_factor);
390
                sin_roll = (int32_t)(c_sin_8192(angle));
391
                cos_roll = (int32_t)(c_cos_8192(angle));
700 killagreg 392
 
741 killagreg 393
                Hx_corr = Hx * cos_pitch;
394
                Hx_corr -= Hz * sin_pitch;
395
                Hx_corr /= 8192;
700 killagreg 396
 
741 killagreg 397
                Hy_corr = Hy * cos_roll;
398
                Hy_corr += Hz * sin_roll;
399
                Hy_corr /= 8192;
700 killagreg 400
 
741 killagreg 401
                // calculate Heading
402
                heading = c_atan2(Hy_corr, Hx_corr);
700 killagreg 403
 
741 killagreg 404
                // atan returns angular range from -180 deg to 180 deg in counter clockwise notation
405
                // but the compass course is defined in a range from 0 deg to 360 deg clockwise notation.
406
                if (heading < 0) heading = -heading;
407
                else heading = 360 - heading;
408
        }
409
        else // MM3_Timeout = 0 i.e now new data from external board
410
        {
765 killagreg 411
                if(!BeepTime) BeepTime = 100; // make noise to signal the compass problem
741 killagreg 412
                heading = -1;
413
        }
700 killagreg 414
return heading;
415
}