HI All,
I'm attempting to find a way to hook up my HC-SR04 to Galileo and since the NewPing and Ultrasonic libraries both don't work because of either the pulseIn function not being implemented or dependencies on the AVR. I decided to try a different route and wrote up this sketch using digital read and write functions to get the reading from the HC-SR04. The sketch works fine on the Arduino Uno, but when I transfer the sketch to the Galileo board it appears to hang if the value from the HC-SR04 changes... I'm stuck on figuring this out any insights would be awesome.
#define ECHOPIN 3
#define TRIGGERPIN 4
#define US_ROUNDTRIP_IN 146
#define US_ROUNDTRIP_CM 57
#define PingConvert(echoTime, conversionFactor) ((echoTime + conversionFactor / 2) / conversionFactor)
unsigned long pinStart;
unsigned long pinEnd;
void setup(){ pinMode(TRIGGERPIN, OUTPUT); pinMode(ECHOPIN, INPUT); pinMode(13, OUTPUT);
}
void loop(){ digitalWrite(TRIGGERPIN,LOW); delayMicroseconds(2); digitalWrite(TRIGGERPIN,HIGH); delayMicroseconds(10); digitalWrite(TRIGGERPIN,LOW); while(digitalRead(ECHOPIN)==LOW){}; //waiting for the pin to trigger pinStart = micros(); while(digitalRead(ECHOPIN)==HIGH){};//waiting for the pin to go low pinEnd = micros(); unsigned int echoTime = pinEnd - pinStart; if(PingConvert(echoTime,US_ROUNDTRIP_IN)<6){ digitalWrite(13, HIGH); delay(2000); } digitalWrite(13, LOW); delay(1000);
}