44 lines
1.1 KiB
C++
44 lines
1.1 KiB
C++
#include <math.h>
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#define WindSensorPin (2)
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volatile unsigned long Rotations; // cup rotation counter used in interrupt routine
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volatile unsigned long ContactBounceTime; // Timer to avoid contact bounce in interrupt routine
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float WindSpeed; // speed miles per hour
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void setup()
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{
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Serial.begin(9600);
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pinMode(WindSensorPin, INPUT);
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attachInterrupt(digitalPinToInterrupt(WindSensorPin), isr_rotation, FALLING);
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Serial.println("Rotations\tKm/h");
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}
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void loop()
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{
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Rotations = 0; // Set Rotations count to 0 ready for calculations
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sei(); // Enables interrupts
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delay (3000); // Wait 3 seconds to average
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cli(); // Disable interrupts
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// convert to mp/h using the formula V=P(2.25/T)
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// V = P(2.25/3) = P * 0.75
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WindSpeed = (Rotations * 0.75) * 1.609344;
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Serial.print(Rotations); Serial.print("\t\t");
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Serial.println(WindSpeed);
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}
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// This is the function that the interrupt calls to increment the rotation count
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void isr_rotation()
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{
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if ((millis() - ContactBounceTime) > 15 ) // debounce the switch contact.
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{
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Rotations++;
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ContactBounceTime = millis();
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}
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}
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