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14 | 14 | ||
15 | #include "rc.h" |
15 | #include "rc.h" |
Line 16... | Line 16... | ||
16 | #include "fc.h" |
16 | #include "fc.h" |
17 | 17 | ||
18 | volatile int16_t PPM_in[11]; |
18 | volatile int16_t PPM_in[11]; |
- | 19 | volatile int16_t PPM_diff[11]; |
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Line 19... | Line 20... | ||
19 | volatile int16_t PPM_diff[11]; // das diffenzierte Stick-Signal |
20 | volatile uint8_t NewPpmData = 1; |
20 | volatile uint8_t NewPpmData = 1; |
- | |
21 | 21 | volatile uint8_t SenderOkay = 0; |
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22 | /***************************************************************/ |
22 | |
23 | /* zum decodieren des PPM-Signals wird Timer1 mit seiner Input */ |
- | |
24 | /* Capture Funktion benutzt: */ |
23 | /***************************************************************/ |
25 | /***************************************************************/ |
24 | /* 16bit timer 1 is used to decode the PPM-Signal */ |
- | 25 | /***************************************************************/ |
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- | 26 | void rc_sum_init (void) |
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26 | 27 | { |
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- | 28 | uint8_t sreg = SREG; |
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Line -... | Line 29... | ||
- | 29 | ||
- | 30 | // disable all interrupts before reconfiguration |
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- | 31 | cli(); |
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- | 32 | ||
- | 33 | // PPM-signal is connected to the Input Capture Pin (PD6) of timer 1 |
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27 | void rc_sum_init (void) |
34 | DDRD &= ~(1<<DDD6); |
- | 35 | PORTD |= (1<<PORTD6); |
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- | 36 | ||
- | 37 | // Timer/Counter1 Control Register A, B, C |
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- | 38 | ||
- | 39 | // Normal Mode (bits: WGM13=0, WGM12=0, WGM11=0, WGM10=0) |
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- | 40 | // Compare output pin A & B is disabled (bits: COM1A1=0, COM1A0=0, COM1B1=0, COM1B0=0) |
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- | 41 | // Set clock source to SYSCLK/64 (bit: CS12=0, CS11=1, CS10=1) |
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- | 42 | // Enable input capture noise cancler (bit: ICNC1=1) |
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28 | { |
43 | // Trigger on positive edge of the input capture pin (bit: ICES1=1), |
- | 44 | // Therefore the counter incremets at a clock of 20 MHz/64 = 312.5 kHz or 3.2µs |
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29 | TCCR1B=(1<<CS11)|(1<<CS10)|(1<<ICES1)|(1<<ICNC1);//|(1 << WGM12); //timer1 prescale 64 |
45 | // The longest period is 0xFFFF / 312.5 kHz = 0.209712 s. |
- | 46 | TCCR1A &= ~((1<<COM1A1)|(1<<COM1A0)|(1<<COM1B1)|(1<<COM1B0)|(1<<WGM11)|(1<<WGM10)); |
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- | 47 | TCCR1B &= ~((1<<WGM13)|(1<<WGM12)|(1<<CS12)); |
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- | 48 | TCCR1B |= (1<<CS11)|(1<<CS10)|(1<<ICES1)|(1<<ICNC1); |
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- | 49 | TCCR1C &= ~((1<<FOC1A)|(1<<FOC1B)); |
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- | 50 | ||
- | 51 | // Timer/Counter1 Interrupt Mask Register |
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- | 52 | ||
30 | 53 | // Enable Input Capture Interrupt (bit: ICIE1=1) |
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Line 31... | Line -... | ||
31 | // PWM |
- | |
32 | //TCCR1A = (1 << COM1B1) | (1 << WGM11) | (1 << WGM10); |
54 | // Disable Output Compare A & B Match Interrupts (bit: OCIE1B=0, OICIE1A=0) |
33 | //TCCR1B |= (1 << WGM12); |
55 | // Disable Overflow Interrupt (bit: TOIE1=0) |
34 | //OCR1B = 55; |
56 | TIMSK1 &= ~((1<<OCIE1B)|(1<<OCIE1A)|(1<<TOIE1)); |
- | 57 | TIMSK1 |= (1<<ICIE1); |
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35 | 58 | ||
36 | TIMSK1 |= _BV(ICIE1); |
59 | AdNeutralGier = 0; |
Line 37... | Line -... | ||
37 | AdNeutralGier = 0; |
- | |
38 | AdNeutralRoll = 0; |
- | |
39 | AdNeutralNick = 0; |
- | |
40 | return; |
- | |
Line -... | Line 60... | ||
- | 60 | AdNeutralRoll = 0; |
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- | 61 | AdNeutralNick = 0; |
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- | 62 | ||
- | 63 | SREG = sreg; |
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- | 64 | } |
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- | 65 | ||
- | 66 | ||
- | 67 | /********************************************************************/ |
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- | 68 | /* Every time a positive edge is detected at PD6 */ |
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- | 69 | /********************************************************************/ |
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- | 70 | /* |
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- | 71 | The PPM-Frame length is 22.5 ms. |
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- | 72 | Channel high pulse width range is 0.7 ms to 1.7 ms completed by an 0.3 ms low pulse. |
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- | 73 | The mininimum time delay of two events coding a channel is ( 0.7 + 0.3) ms = 1 ms. |
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41 | } |
74 | The maximum time delay of two events coding a chanel is ( 1.7 + 0.3) ms = 2 ms. |
42 | 75 | The minimum duration of all channels at minimum value is 8 * 1 ms = 8 ms. |
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43 | //############################################################################ |
76 | The maximum duration of all channels at maximum value is 8 * 2 ms = 16 ms. |
44 | //Diese Routine startet und inizialisiert den Timer für RC |
77 | The remaining time of (22.5 - 8 ms) ms = 14.5 ms to (22.5 - 16 ms) ms = 6.5 ms is |
- | 78 | the syncronization gap. |
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- | 79 | */ |
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- | 80 | ISR(TIMER1_CAPT_vect) // typical rate of 1 ms to 2 ms |
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- | 81 | { |
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- | 82 | static uint16_t oldICR1 = 0; |
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- | 83 | int16_t signal = 0, tmp; |
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- | 84 | static int16_t index; |
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45 | SIGNAL(SIG_INPUT_CAPTURE1) |
- | |
46 | //############################################################################ |
- | |
Line 47... | Line 85... | ||
47 | 85 | ||
48 | { |
- | |
49 | static unsigned int AltICR=0; |
86 | // 16bit Input Capture Register ICR1 contains the timer value TCNT1 |
- | 87 | // at the time the edge was detected |
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- | 88 | ||
- | 89 | // calculate the time delay to the previous event time which is stored in oldICR1 |
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- | 90 | signal = (uint16_t) ICR1 - oldICR1; |
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- | 91 | oldICR1 = ICR1; |
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- | 92 | ||
- | 93 | ||
- | 94 | //sync gap? (3.52 ms < signal < 25.6 ms) |
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50 | signed int signal = 0,tmp; |
95 | if((signal > 1100) && (signal < 8000)) |
51 | static int index; |
96 | { |
52 | - | ||
53 | signal = (unsigned int) ICR1 - AltICR; |
- | |
54 | AltICR = ICR1; |
- | |
55 | 97 | // if a sync gap happens and there where at least 4 channels decoded before |
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56 | //Syncronisationspause? |
98 | // then the NewPpmData flag is reset indicating valid data in the PPM_in[] array. |
57 | // if((signal > (int) Parameter_UserParam2 * 10) && (signal < 8000)) |
- | |
58 | if((signal > 1100) && (signal < 8000)) |
99 | if(index >= 4) NewPpmData = 0; // Null means NewData |
- | 100 | // synchronize channel index |
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- | 101 | index = 1; |
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- | 102 | } |
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- | 103 | else // within the PPM frame |
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- | 104 | { |
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59 | { |
105 | if(index < 10) // channel limit is 9 because of the frame length of 22.5 ms |
60 | if(index >= 4) NewPpmData = 0; // Null bedeutet: Neue Daten |
106 | { |
- | 107 | // check for valid signal length (0.8 ms < signal < 2.1984 ms) |
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61 | index = 1; |
108 | if((signal > 250) && (signal < 687)) |
62 | } |
109 | { |
- | 110 | signal -= 466; // offset of 1.4912 ms ??? (469 * 3.2µs = 1.5008 ms) |
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63 | else |
111 | // check for stable signal |
64 | { |
112 | // the deviation of the current signal level from the average must be less than 6 (aprox. 1%) |
65 | if(index < 10) |
113 | if(abs(signal - PPM_in[index]) < 6) |
66 | { |
114 | { |
- | 115 | // a good signal condition increases SenderOkay by 10 |
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67 | if((signal > 250) && (signal < 687)) |
116 | // SignalOkay is decremented every 2 ms in timer0.c |
68 | { |
117 | // this variable is a level for the average rate of noiseless signal |
69 | signal -= 466; |
118 | if(SenderOkay < 200) SenderOkay += 10; |
70 | // Stabiles Signal |
119 | } |
71 | if(abs(signal - PPM_in[index]) < 6) { if(SenderOkay < 200) SenderOkay += 10;} |
120 | // calculate exponential history for signal |
- | 121 | tmp = (3 * (PPM_in[index]) + signal) / 4; |
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72 | // tmp = (7 * (PPM_in[index]) + signal) / 8; |
122 | if(tmp > signal+1) tmp--; else |
73 | tmp = (3 * (PPM_in[index]) + signal) / 4; |
123 | if(tmp < signal-1) tmp++; |
74 | if(tmp > signal+1) tmp--; else |
124 | // calculate signal difference on good signal level |
75 | if(tmp < signal-1) tmp++; |
125 | if(SenderOkay >= 195) PPM_diff[index] = ((tmp - PPM_in[index]) / 3) * 3; // cut off lower 3 bit for nois reduction |
76 | if(SenderOkay >= 195) PPM_diff[index] = ((tmp - PPM_in[index]) / 3) * 3; |
126 | else PPM_diff[index] = 0; |
77 | else PPM_diff[index] = 0; |
127 | PPM_in[index] = tmp; // update channel value |