1 | /*
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2 | * Ultrasonic sensor HC-05 interfacing with AVR ATmega16
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3 | * http://www.electronicwings.com
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4 | */
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5 |
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6 | #define F_CPU 16000000UL
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7 | #include <Arduino.h>
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8 | #include <avr/io.h>
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9 | #include <avr/interrupt.h>
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10 | #include <util/delay.h>
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11 | #include <stdlib.h>
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12 |
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13 | #define Trigger_pin PA0 /* Trigger pin */
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14 |
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15 | int TimerOverflow = 0;
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16 | double count = 0;
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17 | double speed = 0;
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18 | double distance = 0;
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19 |
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20 | double mittelwert = 0;
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21 |
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22 | uint8_t intterupt = 0;
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23 | uint8_t logCounter = 0;
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24 |
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25 | ISR(INT0_vect)
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26 | {
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27 | intterupt = 1;
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28 | }
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29 |
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30 | ISR(TIMER4_OVF_vect)
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31 | {
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32 | TimerOverflow++; /* Increment Timer Overflow count */
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33 | }
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34 |
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35 | void interruptconfig()
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36 | {
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37 | EICRA |= (1 << ISC01) | (1 << ISC00);
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38 | EIMSK |= (1 << INT0);
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39 | // sei();
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40 | }
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41 |
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42 | int main(void)
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43 | {
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44 | // char string[10];
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45 | // long count;
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46 | // double distance;
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47 | interruptconfig();
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48 | Serial.begin(9600);
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49 |
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50 | DDRA = (1 << Trigger_pin); /* Make trigger pin as output */
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51 | PORTA = (1 << Trigger_pin); /* Turn on Pull-up */
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52 |
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53 | sei(); /* Enable global interrupt */
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54 | TIMSK4 = (1 << TOIE4); /* Enable Timer1 overflow interrupts */
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55 | TCCR4A = 0; /* Set all bit to zero Normal operation */
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56 |
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57 | while (1)
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58 | {
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59 | /* Give 10us trigger pulse on trig. pin to HC-SR04 */
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60 | PORTA |= (1 << Trigger_pin);
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61 | _delay_us(10);
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62 | PORTA &= (~(1 << Trigger_pin));
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63 |
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64 | TCNT4 = 0; /* Clear Timer counter */
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65 | TCCR4B = 0x41; /* Capture on rising edge, No prescaler*/
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66 | TIFR4 = 1 << ICF4; /* Clear ICP flag (Input Capture flag) */
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67 | TIFR4 = 1 << TOV4; /* Clear Timer Overflow flag */
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68 | TimerOverflow = 0; /* Clear Timer overflow count */
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69 | /*Calculate width of Echo by Input Capture (ICP) */
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70 |
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71 | while ((TIFR4 & (1 << ICF4)) == 0)
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72 | ; /* Wait for rising edge */
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73 | TCNT4 = 0; /* Clear Timer counter */
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74 | TCCR4B = 0x01; /* Capture on falling edge, No prescaler */
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75 | TIFR4 = 1 << ICF4; /* Clear ICP flag (Input Capture flag) */
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76 | TIFR4 = 1 << TOV4; /* Clear Timer Overflow flag */
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77 | // TimerOverflow = 0; /* Clear Timer overflow count */
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78 |
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79 | while ((TIFR4 & (1 << ICF4)) == 0)
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80 | ; /* Wait for falling edge */
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81 | count = ICR4 + (65535 * TimerOverflow); /* Take count */
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82 | /* 8MHz Timer freq, sound speed =343 m/s */
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83 | //54.88 cm *100 / (count * taktDauer / 100) =
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84 | speed = distance / (((double)count * 62.5) / 100);
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85 |
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86 | if (intterupt == 1)
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87 | {
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88 | Serial.print("Distanz: ");
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89 | intterupt = 0;
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90 | distance = (double)count / 465.6;
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91 | Serial.println(distance);
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92 | }
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93 |
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94 | logCounter++;
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95 |
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96 | mittelwert = (double)(mittelwert + (((speed * 100000) - 343) * 1000));
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97 |
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98 | if (logCounter == 10)
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99 | {
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100 | logCounter = 0;
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101 | Serial.println((double)(mittelwert / 1000) / 10);
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102 | mittelwert = 0;
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103 | }
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104 |
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105 | // distance = (double)count / 466.47;
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106 | // Serial.println((speed * 100000) - 343);
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107 | // Serial.println((speed * 100000));
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108 | // Serial.println(distance);
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109 | _delay_ms(200);
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110 | }
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111 | }
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