Hallo,
versuche leider vergebens den HC-SR04 mit dem Atmega zu verbinden bzw
anzusteuern.
Möchte eigentlich erstmal nur eine LED Leuchten lassen, wenn eine
ENtfernung unterschritten wird.
Kann sich den Code mal wer anschauen?
Wo liegt der Fehler?
Danke.
1 | /*
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2 | * Ultraschall.c
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3 | *
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4 | * Created: 16.08.2014 17:21:46
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5 | * Author: Pi
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6 | */
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7 | /*Sensor | MCU
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8 | _____________
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9 | Trig | PC0
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10 | Echo | PC1
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11 | */
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12 | #include <avr/io.h>
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13 | //#include <util/delay.h>
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14 |
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15 | #define US_PORT PORTC
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16 | #define US_PIN PINC
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17 | #define US_DDR DDRC
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18 |
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19 | #define US_TRIG_POS PC0
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20 | #define US_ECHO_POS PC1
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21 |
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22 |
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23 | #define US_ERROR -1
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24 | #define US_NO_OBSTACLE -2
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25 |
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26 | void HCSR04Init();
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27 | void HCSR04Trigger();
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28 |
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29 | void HCSR04Init()
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30 | {
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31 | US_DDR|=(1<<US_TRIG_POS);
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32 | }
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33 |
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34 | void HCSR04Trigger()
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35 | {
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36 | //Send a 10uS pulse on trigger line
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37 |
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38 | US_PORT|=(1<<US_TRIG_POS); //high
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39 |
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40 | //_delay_us(15); //wait 15uS
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41 |
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42 | US_PORT&=~(1<<US_TRIG_POS); //low
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43 | }
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44 |
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45 | uint16_t GetPulseWidth()
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46 | {
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47 | uint32_t i,result;
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48 |
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49 | //Wait for the rising edge
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50 | for(i=0;i<600000;i++)
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51 | {
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52 | if(!(US_PIN & (1<<US_ECHO_POS)))
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53 | continue; //Line is still low, so wait
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54 | else
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55 | break; //High edge detected, so break.
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56 | }
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57 |
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58 | if(i==600000)
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59 | return US_ERROR; //Indicates time out
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60 |
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61 | //High Edge Found
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62 |
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63 | //Setup Timer1
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64 | TCCR1A=0X00;
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65 | TCCR1B=(1<<CS11); //Prescaler = Fcpu/8
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66 | TCNT1=0x00; //Init counter
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67 |
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68 | //Now wait for the falling edge
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69 | for(i=0;i<600000;i++)
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70 | {
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71 | if(US_PIN & (1<<US_ECHO_POS))
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72 | {
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73 | if(TCNT1 > 60000) break; else continue;
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74 | }
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75 | else
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76 | break;
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77 | }
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78 |
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79 | if(i==600000)
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80 | return US_NO_OBSTACLE; //Indicates time out
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81 |
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82 | //Falling edge found
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83 |
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84 | result=TCNT1;
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85 |
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86 | //Stop Timer
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87 | TCCR1B=0x00;
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88 |
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89 | if(result > 60000)
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90 | return US_NO_OBSTACLE; //No obstacle
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91 | else
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92 | return (result>>1);
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93 | }
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94 |
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95 |
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96 |
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97 |
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98 | int main(void)
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99 | {
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100 | uint16_t r;
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101 | int d;
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102 | //_delay_ms(100);
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103 |
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104 | HCSR04Init();
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105 |
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106 | DDRB |= (1 << PB0);
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107 |
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108 |
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109 | while(1)
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110 | {
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111 | //Send a trigger pulse
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112 | HCSR04Trigger();
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113 | r=GetPulseWidth(); //Measure the width of pulse
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114 |
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115 | d=(r/58.0);
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116 |
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117 | if (d<5)
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118 | {
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119 | PORTB |= (1 << PB0);
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120 | }
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121 | else
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122 | {
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123 | PORTB |= (1 << PB1);
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124 | }
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125 | }
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126 | }
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