Measuring time between two photoresitors and printing time on lcd

Other Hardware Sensors
1

I am working on a project that is supposed to record the time difference between two photoresistors that are 4in apart. The photoresistors are sensing the passing of water or other liquids on a chute/ramp.

I have looked online and haven't seen a similar project. I want to be able to display the time difference on a lcd.

I have my lcd up and running but I'm not sure how to code the time difference. My photoresistors are connected to A0 and A1 and I am using digital pins 7-12 for the lcd. If anyone has any advice that would be very appreciated!

I'm sure I missed something so ask any clarifying questions thanks!

2

Basically this:

if ((digitalRead(sensor0) == LOW) && (timeCheckin Progress == 0)){
startTime = micros();
timeCheckinProgress = 1;
}
if ((timeCheckinProgress == 1) && (digitalRead(sensor1) == LOW)){
endTIme = micros();
timeCheckinProgress = 0;
duration = endTime - startTIme;
Serial.println(duration);
}
3

It may be more accurate (and easier software wise - no need to poll the pins constantly or miss the event because you're writing to the LCD) to use interrupts on the pins, and record the time in millis() as above in the ISR.