Zeroplus Arduino starter kit with Logic Analyzer Manual page 69

CODE EXPLANATION
• unsigned long currentMillis = millis() When called, this function
returns the number of milliseconds elapsed since the program
started.
• if(soundSensor == 1){
soundLed = HIGH;
soundStartTime = currentMillis.
}
If the sensor detects a sound, we set the flag SoundLed. We also save
the time it occurred.
• if(soundLed == HIGH){
soundCurrentTime = currentMillis;
if((soundCurrentTime - soundStartTime) >= timeInterval){
soundLed = LOW;
}
This portion of code calculates the elapsed time between now and the
last sound detected by the sensor. This way we can keep the LED lit
for a certain time before turning it off .
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