When I put my finger on the photoresistor I want the light to go a lot dimmer.. how can I make this happen?
const int sensorPin = 0;
const int ledPin = 9;
// We'll also set up some global variables for the light level:
int lightLevel, high = 0, low = 1023;
void setup()
{
// We'll set up the LED pin to be an output.
// (We don't need to do anything special to use the analog input.)
pinMode(ledPin, OUTPUT);
}
void loop()
{
// Just as we've done in the past, we'll use the analogRead()
// function to measure the voltage coming from the photoresistor
// resistor pair. This number can range between 0 (0 Volts) and
// 1023 (5 Volts), but this circuit will have a smaller range
// between dark and light.
lightLevel = analogRead(sensorPin);
// lightLevel = map(lightLevel, 0, 1023, 0, 255);
// lightLevel = constrain(lightLevel, 0, 255);
manualTune(); // manually change the range from light to dark
//autoTune(); // have the Arduino do the work for us!
analogWrite(ledPin, lightLevel);
}
void manualTune()
lightLevel = map(lightLevel, 0, 1023, 0, 255);
lightLevel = constrain(lightLevel, 0, 255);
// Now we'll return to the main loop(), and send lightLevel
// to the LED.
}
void autoTune()
{
if (lightLevel < low)
{
low = lightLevel;
}
// We also initialized "high" to be 0. We'll save anything
// we read that's higher than that:
if (lightLevel > high)
{
high = lightLevel;
}
// Once we have the highest and lowest values, we can stick them
// directly into the map() function. No manual tweaking needed!
// One trick we'll do is to add a small offset to low and high,
// to ensure that the LED is fully-off and fully-on at the limits
// (otherwise it might flicker a little bit).
lightLevel = map(lightLevel, low+30, high-30, 0, 255);
lightLevel = constrain(lightLevel, 0, 255);
// Now we'll return to the main loop(), and send lightLevel
// to the LED.
}