// Initialize Pins
int analogPin = 0;
int chargePin = 13;
int dischargePin = 11; //speeds up discharging process, not necessary though
// Initialize Resistor
int resistorValue = 10000;
// Initialize Timer
unsigned long startTime;
unsigned long elapsedTime;
// Initialize Capacitance Variables
float microFarads;
float nanoFarads;
void setup()
{
pinMode(chargePin, OUTPUT);
digitalWrite(chargePin, LOW);
Serial.begin(9600); // Necessary to print data to serial monitor over USB
}
void loop()
{
digitalWrite(chargePin, HIGH); // Begins charging the capacitor
startTime = millis(); // Begins the timer
while(analogRead(analogPin) < 648)
{
// Does nothing until capacitor reaches 63.2% of total voltage
}
elapsedTime= millis() - startTime; // Determines how much time it took to charge capacitor
microFarads = ((float)elapsedTime / resistorValue) * 1000;
Serial.print(elapsedTime);
Serial.print(" mS ");
if (microFarads > 1) // Determines if units should be micro or nano and prints accordingly
{
Serial.print((long)microFarads);
Serial.println(" microFarads");
}
else
{
nanoFarads = microFarads * 1000.0;
Serial.print((long)nanoFarads);
Serial.println(" nanoFarads");
delay(500);
}
digitalWrite(chargePin, LOW); // Stops charging capacitor
pinMode(dischargePin, OUTPUT);
digitalWrite(dischargePin, LOW); // Allows capacitor to discharge
while(analogRead(analogPin) > 0)
{
// Do nothing until capacitor is discharged
}
pinMode(dischargePin, INPUT); // Prevents capacitor from discharging
}
