Currently we are using the Serial Monitor, but Part 2 will be about the 3 seven segment display and I2C port expander used to drive them.
Wiring:
The circuit diagram is the same as the one we posted here, but just doubled.
Code:
int sensor1 = 4;
int sensor2 = 5;
bool s1Covered;
bool s2Covered;
float start, finish, elapsed, miles, hours, mph, scaleMPH;
float distance = 24; //inches between sensors
int started=0, finished=0;
int scale=87;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
pinMode(sensor1, INPUT);
pinMode(sensor2, INPUT);
}
void loop() {
// put your main code here, to run repeatedly:
//finished=0;
s1Covered=digitalRead(sensor1);
if (s1Covered==0 && started==0){
start=millis();
started=1;
Serial.println("Started");
}
s2Covered=digitalRead(sensor2);
if (s2Covered==0 && started==1){
finish=millis();
finished=1;
Serial.println("Finished");
elapsed = finish-start; // millis
elapsed = elapsed /1000; // seconds
Serial.print("Seconds: ");
Serial.println(elapsed);
miles = distance / 63360; // miles
hours = elapsed / 3600; // hours
mph = miles / hours;
scaleMPH = mph * scale;
Serial.print("Scale MPH: ");
Serial.println(scaleMPH);
started=0;
finished=0;
}
}