1 | #define CODINGTIMERCNT TCNT1
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2 | #define CODINGTIMERCTRA TCCR1A
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3 | #define CODINGTIMERCTRB TCCR1B
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4 | #define CODINGTIMERCTRC TCCR1C
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5 | #define CODINGTIMERMSK TIMSK
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6 | #define CODINGTIMER_OVF TIMER1_OVF_vect
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7 | #define CODINGTIMER_IPC TIMER1_CAPT_vect
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8 |
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9 | /* prescaler timer 1 page 107 */
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10 | #define PRESC_T1 64
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11 | #define PRES_BITS 0x03
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12 |
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13 | /* 2,5 ms - 12800Hz */
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14 | #define BASE_IMP 10000UL/24UL
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15 | #define BASE_TOL 10000UL/8UL /* 0,8ms - tolerance */
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16 |
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17 | /* precalculation */
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18 | #define IMP_MIN (F_CPU/(PRESC_T1 * BASE_IMP)) // 300 ticks
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19 | #define SPACE_LOW (32UL * IMP_MIN) // 9600 ticks
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20 | #if (SPACE_LOW > 65535UL)
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21 | #error invalid prescaler, out of border
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22 | #endif
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23 | #define TOLERANCE (F_CPU/(PRESC_T1 * BASE_TOL)) // 100ticks
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24 | #define BIT1_LOW (2UL * IMP_MIN) // 600 ticks
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25 | #define BIT0_LOW (1UL * IMP_MIN) // 300 ticks
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26 |
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27 | void HardwareInit(void)
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28 | {
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29 | CODINGTIMERCNT = 0x0000; //Load TC1 count value
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30 | sbi(CODINGTIMERMSK,ICIE1); // Timer1 Input Capture & Interrupt Enable
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31 | sbi(CODINGTIMERMSK,TOIE1); // Timer1 Overflow
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32 | CODINGTIMERCTRA = 0x00; //Normal mode
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33 | sbi(CODINGTIMERCTRB,ICES1); //Look for Falling Edge on ICP1
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34 | CODINGTIMERCTRB |= (PRES_BITS<<CS10); //prescale = clock source / 64
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35 | }
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36 |
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37 | ISR(CODINGTIMER_OVF)
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38 | {
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39 | /* disable and set to maximum */
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40 | cbi(CODINGTIMERMSK,TOIE1);
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41 | CODINGTIMERCTRB &= ~(PRES_BITS<<CS10); // off
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42 | CODINGTIMERCNT = 0xFFFF;
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43 | }
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44 |
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45 | ISR(CODINGTIMER_IPC)
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46 | {
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47 | CODINGTIMERCNT = 0UL;
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48 | sbi(CODINGTIMERMSK,TOIE1);
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49 | CODINGTIMERCTRB |= (PRES_BITS<<CS10); // on
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50 | uwTime = ICR1;
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51 | tgl(CODINGTIMERCTRB,ICES1); /* change edge detection */
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52 | }
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53 |
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54 | void SuchDasBit(uwTime)
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55 | {
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56 | if (ubEdge) /* rising edge detected */
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57 | {
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58 | sbi(PORTB,PB1); //test
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59 | if (uwTime > SPACE_LOW) {
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60 | ... einmal hier
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61 | }
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62 | else if ((uwTime > BIT1_LOW_M)
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63 | && (uwTime < BIT1_LOW_P))
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64 | {
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65 | ... nie hier, warum ?
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66 | } else if ((uwTime > BIT0_LOW_M)
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67 | && (uwTime < BIT0_LOW_P))
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68 | {
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69 | ... nie hier, warum ?
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70 | } else {
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71 | ... dann immer hier
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72 | }
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73 | } else { /* falling edge detected */
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74 | cbi(PORTB,PB1); //test
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75 | if ((uwTime > BIT1_HIGH_M)
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76 | && (uwTime < BIT1_HIGH_P))
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77 | {
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78 | .... nie hier warum?
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79 | }
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80 | else if ((uwTime > BIT0_HIGH_M)
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81 | && (uwTime < BIT0_HIGH_P))
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82 | {
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83 | ... nie hier, warum ?
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84 | } else {
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85 | ... und immmer hier
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86 | }
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87 | }
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88 | }
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