43 lines
945 B
C
43 lines
945 B
C
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#include <wiringPi.h>
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#include <sys/time.h>
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#include <stdlib.h>
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#include <stdio.h>
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int main(int argc, char * argv[])
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{
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int i;
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if( argc != 3) {
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exit(0);
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}
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int pin_tring = atol(argv[1]);
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int pin_echo = atol(argv[2]);
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struct timeval tv1;
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struct timeval tv2;
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long start_time, stop_time;
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float distance;
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if(wiringPiSetup() == -1) {
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exit(0);
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return 0;
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}
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digitalWrite(pin_tring, LOW);
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digitalWrite(pin_tring, HIGH);
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delayMicroseconds(10);
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digitalWrite(pin_tring, LOW);
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while(!(digitalRead(pin_echo) == 1));
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gettimeofday(&tv1, NULL);
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while(!(digitalRead(pin_echo) == 0));
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gettimeofday(&tv2, NULL);
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start_time = tv1.tv_sec * 1000000 + tv1.tv_usec;
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stop_time = tv2.tv_sec * 1000000 + tv2.tv_usec;
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distance = (float)(stop_time - start_time) / 1000000 * 34000 / 2;
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printf("%0.0f\n", distance);
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return distance;
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}
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