Rev 2135 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
2108 | - | 1 | #include <avr/io.h> |
2 | #include <avr/interrupt.h> |
||
3 | #include <avr/pgmspace.h> |
||
4 | #include <stdlib.h> |
||
5 | |||
6 | #include "analog.h" |
||
7 | #include "configuration.h" |
||
8 | #include "attitude.h" |
||
9 | #include "printf_P.h" |
||
10 | #include "isqrt.h" |
||
11 | #include "twimaster.h" |
||
12 | |||
13 | // for Delay functions |
||
14 | #include "timer0.h" |
||
15 | |||
16 | // For reading and writing acc. meter offsets. |
||
17 | #include "eeprom.h" |
||
18 | |||
19 | // For debugOut |
||
20 | #include "output.h" |
||
21 | |||
22 | // set ADC enable & ADC Start Conversion & ADC Interrupt Enable bit |
||
23 | #define startADC() (ADCSRA |= (1<<ADEN)|(1<<ADSC)|(1<<ADIE)) |
||
24 | |||
25 | const char* recal = ", recalibration needed."; |
||
26 | volatile uint16_t ADSensorInputs[8]; |
||
27 | |||
28 | /* |
||
29 | * These 4 exported variables are zero-offset. The "PID" ones are used |
||
30 | * in the attitude control as rotation rates. The "ATT" ones are for |
||
31 | * integration to angles. |
||
32 | */ |
||
33 | int16_t gyro_PID[3]; |
||
34 | int16_t gyro_ATT[3]; |
||
35 | int16_t gyroD[3]; |
||
36 | int16_t gyroDWindow[3][GYRO_D_WINDOW_LENGTH]; |
||
37 | uint8_t gyroDWindowIdx = 0; |
||
38 | |||
39 | /* |
||
40 | * Airspeed |
||
41 | */ |
||
2132 | - | 42 | //int16_t airpressure; |
43 | //uint16_t airspeedVelocity = 0; |
||
2109 | - | 44 | //int16_t airpressureWindow[AIRPRESSURE_WINDOW_LENGTH]; |
45 | //uint8_t airpressureWindowIdx = 0; |
||
2108 | - | 46 | |
47 | /* |
||
48 | * Offset values. These are the raw gyro and acc. meter sums when the copter is |
||
49 | * standing still. They are used for adjusting the gyro and acc. meter values |
||
50 | * to be centered on zero. |
||
51 | */ |
||
52 | sensorOffset_t gyroOffset; |
||
53 | uint16_t airpressureOffset; |
||
54 | |||
55 | /* |
||
56 | * In the MK coordinate system, nose-down is positive and left-roll is positive. |
||
57 | * If a sensor is used in an orientation where one but not both of the axes has |
||
58 | * an opposite sign, PR_ORIENTATION_REVERSED is set to 1 (true). |
||
59 | * Transform: |
||
60 | * pitch <- pp*pitch + pr*roll |
||
61 | * roll <- rp*pitch + rr*roll |
||
62 | * Not reversed, GYRO_QUADRANT: |
||
63 | * 0: pp=1, pr=0, rp=0, rr=1 // 0 degrees |
||
64 | * 1: pp=1, pr=-1,rp=1, rr=1 // +45 degrees |
||
65 | * 2: pp=0, pr=-1,rp=1, rr=0 // +90 degrees |
||
66 | * 3: pp=-1,pr=-1,rp=1, rr=1 // +135 degrees |
||
67 | * 4: pp=-1,pr=0, rp=0, rr=-1 // +180 degrees |
||
68 | * 5: pp=-1,pr=1, rp=-1,rr=-1 // +225 degrees |
||
69 | * 6: pp=0, pr=1, rp=-1,rr=0 // +270 degrees |
||
70 | * 7: pp=1, pr=1, rp=-1,rr=1 // +315 degrees |
||
71 | * Reversed, GYRO_QUADRANT: |
||
72 | * 0: pp=-1,pr=0, rp=0, rr=1 // 0 degrees with pitch reversed |
||
73 | * 1: pp=-1,pr=-1,rp=-1,rr=1 // +45 degrees with pitch reversed |
||
74 | * 2: pp=0, pr=-1,rp=-1,rr=0 // +90 degrees with pitch reversed |
||
75 | * 3: pp=1, pr=-1,rp=-1,rr=1 // +135 degrees with pitch reversed |
||
76 | * 4: pp=1, pr=0, rp=0, rr=-1 // +180 degrees with pitch reversed |
||
77 | * 5: pp=1, pr=1, rp=1, rr=-1 // +225 degrees with pitch reversed |
||
78 | * 6: pp=0, pr=1, rp=1, rr=0 // +270 degrees with pitch reversed |
||
79 | * 7: pp=-1,pr=1, rp=1, rr=1 // +315 degrees with pitch reversed |
||
80 | */ |
||
81 | |||
82 | void rotate(int16_t* result, uint8_t quadrant, uint8_t reversePR, uint8_t reverseYaw) { |
||
83 | static const int8_t rotationTab[] = {1,1,0,-1,-1,-1,0,1}; |
||
84 | // Pitch to Pitch part |
||
85 | int8_t xx = reversePR ? rotationTab[(quadrant+4)%8] : rotationTab[quadrant]; |
||
86 | // Roll to Pitch part |
||
87 | int8_t xy = rotationTab[(quadrant+2)%8]; |
||
88 | // Pitch to Roll part |
||
89 | int8_t yx = reversePR ? rotationTab[(quadrant+2)%8] : rotationTab[(quadrant+6)%8]; |
||
90 | // Roll to Roll part |
||
91 | int8_t yy = rotationTab[quadrant]; |
||
92 | |||
93 | int16_t xIn = result[0]; |
||
94 | result[0] = xx*xIn + xy*result[1]; |
||
95 | result[1] = yx*xIn + yy*result[1]; |
||
96 | |||
97 | if (quadrant & 1) { |
||
98 | // A rotation was used above, where the factors were too large by sqrt(2). |
||
99 | // So, we multiply by 2^n/sqt(2) and right shift n bits, as to divide by sqrt(2). |
||
100 | // A suitable value for n: Sample is 11 bits. After transformation it is the sum |
||
101 | // of 2 11 bit numbers, so 12 bits. We have 4 bits left... |
||
102 | result[0] = (result[0]*11) >> 4; |
||
103 | result[1] = (result[1]*11) >> 4; |
||
104 | } |
||
105 | |||
106 | if (reverseYaw) |
||
107 | result[3] =-result[3]; |
||
108 | } |
||
109 | |||
110 | /* |
||
111 | * Battery voltage, in units of: 1k/11k / 3V * 1024 = 31.03 per volt. |
||
112 | * That is divided by 3 below, for a final 10.34 per volt. |
||
113 | * So the initial value of 100 is for 9.7 volts. |
||
114 | */ |
||
115 | uint16_t UBat = 100; |
||
116 | |||
117 | /* |
||
118 | * Control and status. |
||
119 | */ |
||
120 | volatile uint8_t sensorDataReady = ALL_DATA_READY; |
||
121 | |||
122 | /* |
||
123 | * Experiment: Measuring vibration-induced sensor noise. |
||
124 | */ |
||
125 | uint16_t gyroNoisePeak[3]; |
||
126 | |||
127 | volatile uint8_t adState; |
||
128 | volatile uint8_t adChannel; |
||
129 | |||
130 | // ADC channels |
||
131 | #define AD_UBAT 6 |
||
2132 | - | 132 | //#define AD_AIRPRESSURE 7 |
2108 | - | 133 | |
134 | /* |
||
135 | * Table of AD converter inputs for each state. |
||
136 | * The number of samples summed for each channel is equal to |
||
137 | * the number of times the channel appears in the array. |
||
138 | * The max. number of samples that can be taken in 2 ms is: |
||
139 | * 20e6 / 128 / 13 / (1/2e-3) = 24. Since the main control |
||
140 | * loop needs a little time between reading AD values and |
||
141 | * re-enabling ADC, the real limit is (how much?) lower. |
||
142 | * The acc. sensor is sampled even if not used - or installed |
||
143 | * at all. The cost is not significant. |
||
144 | */ |
||
145 | |||
146 | const uint8_t channelsForStates[] PROGMEM = { |
||
2132 | - | 147 | //AD_AIRPRESSURE, |
148 | AD_UBAT |
||
149 | //AD_AIRPRESSURE, |
||
150 | //AD_AIRPRESSURE, |
||
151 | //AD_AIRPRESSURE, |
||
2108 | - | 152 | }; |
153 | |||
154 | // Feature removed. Could be reintroduced later - but should work for all gyro types then. |
||
155 | // uint8_t GyroDefectPitch = 0, GyroDefectRoll = 0, GyroDefectYaw = 0; |
||
156 | |||
157 | void analog_init(void) { |
||
158 | uint8_t sreg = SREG; |
||
159 | // disable all interrupts before reconfiguration |
||
160 | cli(); |
||
161 | |||
162 | // ADC0 ... ADC7 is connected to PortA pin 0 ... 7 |
||
163 | // DDRA = 0x00; |
||
164 | // PORTA = 0x00; |
||
165 | // Digital Input Disable Register 0 |
||
166 | // Disable digital input buffer for analog adc_channel pins |
||
167 | // DIDR0 = 0xFF; |
||
168 | // external reference, adjust data to the right |
||
169 | ADMUX &= ~((1<<REFS1)|(1<<REFS0)|(1<<ADLAR)); |
||
170 | // set muxer to ADC adc_channel 0 (0 to 7 is a valid choice) |
||
171 | ADMUX = (ADMUX & 0xE0); |
||
172 | //Set ADC Control and Status Register A |
||
173 | //Auto Trigger Enable, Prescaler Select Bits to Division Factor 128, i.e. ADC clock = SYSCKL/128 = 156.25 kHz |
||
174 | ADCSRA = (1<<ADPS2)|(1<<ADPS1)|(1<<ADPS0); |
||
175 | //Set ADC Control and Status Register B |
||
176 | //Trigger Source to Free Running Mode |
||
177 | ADCSRB &= ~((1<<ADTS2)|(1<<ADTS1)|(1<<ADTS0)); |
||
178 | |||
179 | startAnalogConversionCycle(); |
||
180 | |||
2133 | - | 181 | twimaster_init(); |
182 | |||
2108 | - | 183 | // restore global interrupt flags |
184 | SREG = sreg; |
||
185 | } |
||
186 | |||
187 | /* |
||
2135 | - | 188 | * The sensor is installed vertically and the axes are moved around a little... |
2108 | - | 189 | */ |
2133 | - | 190 | int16_t rawGyroValue(uint8_t axis) { |
2135 | - | 191 | switch(axis) { |
192 | case PITCH: |
||
193 | return ITG3200SensorInputs[3]; |
||
194 | case ROLL: |
||
195 | return ITG3200SensorInputs[1]; |
||
196 | case YAW: |
||
197 | return ITG3200SensorInputs[2]; |
||
198 | } |
||
199 | return 0; |
||
2108 | - | 200 | } |
201 | |||
202 | /* |
||
203 | uint16_t rawAccValue(uint8_t axis) { |
||
204 | return sensorInputs[AD_ACC_PITCH-axis]; |
||
205 | } |
||
206 | */ |
||
207 | |||
208 | void measureNoise(const int16_t sensor, |
||
209 | volatile uint16_t* const noiseMeasurement, const uint8_t damping) { |
||
210 | if (sensor > (int16_t) (*noiseMeasurement)) { |
||
211 | *noiseMeasurement = sensor; |
||
212 | } else if (-sensor > (int16_t) (*noiseMeasurement)) { |
||
213 | *noiseMeasurement = -sensor; |
||
214 | } else if (*noiseMeasurement > damping) { |
||
215 | *noiseMeasurement -= damping; |
||
216 | } else { |
||
217 | *noiseMeasurement = 0; |
||
218 | } |
||
219 | } |
||
220 | |||
221 | void startAnalogConversionCycle(void) { |
||
2129 | - | 222 | twimaster_startCycle(); |
2108 | - | 223 | // Stop the sampling. Cycle is over. |
224 | for (uint8_t i = 0; i<8; i++) { |
||
225 | ADSensorInputs[i] = 0; |
||
226 | } |
||
227 | |||
228 | adState = 0; |
||
2132 | - | 229 | adChannel = AD_UBAT; |
2108 | - | 230 | ADMUX = (ADMUX & 0xE0) | adChannel; |
231 | startADC(); |
||
2109 | - | 232 | sensorDataReady = 0; |
2108 | - | 233 | } |
234 | |||
235 | /***************************************************** |
||
236 | * Interrupt Service Routine for ADC |
||
237 | * Runs at 312.5 kHz or 3.2 �s. When all states are |
||
238 | * processed further conversions are stopped. |
||
239 | *****************************************************/ |
||
240 | ISR(ADC_vect) { |
||
241 | ADSensorInputs[adChannel] += ADC; |
||
242 | // set up for next state. |
||
243 | adState++; |
||
244 | if (adState < sizeof(channelsForStates)) { |
||
245 | adChannel = pgm_read_byte(&channelsForStates[adState]); |
||
246 | // set adc muxer to next adChannel |
||
247 | ADMUX = (ADMUX & 0xE0) | adChannel; |
||
248 | // after full cycle stop further interrupts |
||
249 | startADC(); |
||
250 | } else { |
||
251 | sensorDataReady |= ADC_DATA_READY; |
||
252 | // do not restart ADC converter. |
||
253 | } |
||
254 | } |
||
255 | |||
256 | void analog_updateGyros(void) { |
||
257 | // for various filters... |
||
258 | int16_t tempOffsetGyro[3], tempGyro; |
||
259 | |||
260 | for (uint8_t axis=0; axis<3; axis++) { |
||
261 | tempGyro = rawGyroValue(axis); |
||
262 | /* |
||
263 | * Process the gyro data for the PID controller. |
||
264 | */ |
||
265 | |||
266 | // Saturation prevention was removed. No airplane rotates more than 2000 deg/s. |
||
267 | |||
268 | // 2) Apply sign and offset, scale before filtering. |
||
269 | tempOffsetGyro[axis] = (tempGyro - gyroOffset.offsets[axis]); |
||
270 | } |
||
271 | |||
272 | // 2.1: Transform axes. |
||
273 | rotate(tempOffsetGyro, IMUConfig.gyroQuadrant, IMUConfig.imuReversedFlags & IMU_REVERSE_GYRO_PR, IMUConfig.imuReversedFlags & IMU_REVERSE_GYRO_YAW); |
||
274 | |||
275 | for (uint8_t axis=0; axis<3; axis++) { |
||
276 | // 3) Filter. |
||
277 | tempOffsetGyro[axis] = (gyro_PID[axis] * (IMUConfig.gyroPIDFilterConstant - 1) + tempOffsetGyro[axis]) / IMUConfig.gyroPIDFilterConstant; |
||
278 | |||
279 | // 4) Measure noise. |
||
280 | measureNoise(tempOffsetGyro[axis], &gyroNoisePeak[axis], GYRO_NOISE_MEASUREMENT_DAMPING); |
||
281 | |||
282 | // 5) Differential measurement. |
||
283 | // TODO: Examine effects of overruns here, they are quite possible. |
||
284 | int16_t diff = tempOffsetGyro[axis] - gyro_PID[axis]; |
||
285 | gyroD[axis] -= gyroDWindow[axis][gyroDWindowIdx]; |
||
286 | gyroD[axis] += diff; |
||
287 | gyroDWindow[axis][gyroDWindowIdx] = diff; |
||
2141 | - | 288 | debugOut.analog[9+axis] = gyroD[axis]; |
2108 | - | 289 | |
290 | // 6) Done. |
||
291 | gyro_PID[axis] = tempOffsetGyro[axis]; |
||
292 | |||
293 | // Prepare tempOffsetGyro for next calculation below... |
||
294 | tempOffsetGyro[axis] = (rawGyroValue(axis) - gyroOffset.offsets[axis]); |
||
295 | } |
||
296 | |||
297 | /* |
||
298 | * Now process the data for attitude angles. |
||
299 | */ |
||
300 | rotate(tempOffsetGyro, IMUConfig.gyroQuadrant, IMUConfig.imuReversedFlags & IMU_REVERSE_GYRO_PR, IMUConfig.imuReversedFlags & IMU_REVERSE_GYRO_YAW); |
||
301 | |||
302 | // dampenGyroActivity(); |
||
303 | gyro_ATT[PITCH] = tempOffsetGyro[PITCH]; |
||
304 | gyro_ATT[ROLL] = tempOffsetGyro[ROLL]; |
||
305 | gyro_ATT[YAW] = tempOffsetGyro[YAW]; |
||
306 | |||
307 | if (++gyroDWindowIdx >= IMUConfig.gyroDWindowLength) { |
||
308 | gyroDWindowIdx = 0; |
||
309 | } |
||
310 | } |
||
311 | |||
2132 | - | 312 | /* |
2108 | - | 313 | // probably wanna aim at 1/10 m/s/unit. |
2129 | - | 314 | #define LOG_AIRSPEED_FACTOR 0 |
2108 | - | 315 | |
316 | void analog_updateAirspeed(void) { |
||
317 | uint16_t rawAirpressure = ADSensorInputs[AD_AIRPRESSURE]; |
||
2132 | - | 318 | int16_t temp = airpressureOffset - rawAirPressure; |
2109 | - | 319 | // airpressure -= airpressureWindow[airpressureWindowIdx]; |
320 | // airpressure += temp; |
||
321 | // airpressureWindow[airpressureWindowIdx] = temp; |
||
322 | // airpressureWindowIdx++; |
||
323 | // if (airpressureWindowIdx == AIRPRESSURE_WINDOW_LENGTH) { |
||
324 | // airpressureWindowIdx = 0; |
||
325 | // } |
||
2108 | - | 326 | |
2109 | - | 327 | #define AIRPRESSURE_FILTER 16 |
328 | airpressure = ((int32_t)airpressure * (AIRPRESSURE_FILTER-1) + (AIRPRESSURE_FILTER/2) + temp) / AIRPRESSURE_FILTER; |
||
329 | |||
330 | uint16_t p2 = (airpressure<0) ? 0 : airpressure; |
||
331 | airspeedVelocity = (staticParams.airspeedCorrection * isqrt16(p2)) >> LOG_AIRSPEED_FACTOR; |
||
332 | |||
333 | debugOut.analog[17] = airpressure; |
||
334 | debugOut.analog[18] = airpressureOffset; |
||
335 | debugOut.analog[19] = airspeedVelocity; |
||
336 | |||
337 | isFlying = 0; //(airspeedVelocity >= staticParams.isFlyingThreshold); |
||
2108 | - | 338 | } |
2132 | - | 339 | */ |
2108 | - | 340 | |
341 | void analog_updateBatteryVoltage(void) { |
||
342 | // Battery. The measured value is: (V * 1k/11k)/3v * 1024 = 31.03 counts per volt (max. measurable is 33v). |
||
343 | // This is divided by 3 --> 10.34 counts per volt. |
||
344 | UBat = (3 * UBat + ADSensorInputs[AD_UBAT] / 3) / 4; |
||
345 | } |
||
346 | |||
347 | void analog_update(void) { |
||
348 | analog_updateGyros(); |
||
349 | // analog_updateAccelerometers(); |
||
2132 | - | 350 | // analog_updateAirspeed(); |
2108 | - | 351 | analog_updateBatteryVoltage(); |
352 | #ifdef USE_MK3MAG |
||
353 | magneticHeading = volatileMagneticHeading; |
||
354 | #endif |
||
355 | } |
||
356 | |||
357 | void analog_setNeutral() { |
||
358 | twimaster_setNeutral(); |
||
359 | |||
360 | if (gyroOffset_readFromEEProm()) { |
||
361 | printf("gyro offsets invalid%s",recal); |
||
2133 | - | 362 | gyroOffset.offsets[PITCH] = gyroOffset.offsets[ROLL] = 0; |
363 | gyroOffset.offsets[YAW] = 0; |
||
2108 | - | 364 | } |
365 | |||
366 | // Noise is relative to offset. So, reset noise measurements when changing offsets. |
||
367 | for (uint8_t i=PITCH; i<=YAW; i++) { |
||
368 | gyroNoisePeak[i] = 0; |
||
369 | gyroD[i] = 0; |
||
370 | for (uint8_t j=0; j<GYRO_D_WINDOW_LENGTH; j++) { |
||
371 | gyroDWindow[i][j] = 0; |
||
372 | } |
||
373 | } |
||
374 | |||
375 | // Setting offset values has an influence in the analog.c ISR |
||
376 | // Therefore run measurement for 100ms to achive stable readings |
||
377 | delay_ms_with_adc_measurement(100, 0); |
||
378 | |||
379 | // gyroActivity = 0; |
||
380 | } |
||
381 | |||
382 | void analog_calibrate(void) { |
||
2129 | - | 383 | #define OFFSET_CYCLES 120 |
2108 | - | 384 | uint8_t i, axis; |
385 | int32_t offsets[4] = { 0, 0, 0, 0}; |
||
386 | |||
387 | // determine gyro bias by averaging (requires that the copter does not rotate around any axis!) |
||
388 | for (i = 0; i < OFFSET_CYCLES; i++) { |
||
389 | delay_ms_with_adc_measurement(10, 1); |
||
390 | for (axis = PITCH; axis <= YAW; axis++) { |
||
391 | offsets[axis] += rawGyroValue(axis); |
||
392 | } |
||
2132 | - | 393 | // offsets[3] += ADSensorInputs[AD_AIRPRESSURE]; |
2108 | - | 394 | } |
395 | |||
396 | for (axis = PITCH; axis <= YAW; axis++) { |
||
397 | gyroOffset.offsets[axis] = (offsets[axis] + OFFSET_CYCLES / 2) / OFFSET_CYCLES; |
||
398 | } |
||
399 | |||
2132 | - | 400 | /* |
2108 | - | 401 | airpressureOffset = (offsets[3] + OFFSET_CYCLES / 2) / OFFSET_CYCLES; |
402 | int16_t min = 200; |
||
2109 | - | 403 | int16_t max = 1024-200; |
404 | |||
2108 | - | 405 | if(airpressureOffset < min || airpressureOffset > max) |
406 | versionInfo.hardwareErrors[0] |= FC_ERROR0_PRESSURE; |
||
2132 | - | 407 | */ |
2108 | - | 408 | |
409 | gyroOffset_writeToEEProm(); |
||
2132 | - | 410 | airpressureOffset_writeToEEProm(); |
2108 | - | 411 | |
412 | startAnalogConversionCycle(); |
||
413 | } |