Last active
December 21, 2015 22:09
-
-
Save dan-silver/6373548 to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/* Photocell simple testing sketch. | |
Connect one end of the photocell to 5V, the other end to Analog 0. | |
Then connect one end of a 10K resistor from Analog 0 to ground | |
Connect LED from pin 11 through a resistor to ground | |
For more information see http://learn.adafruit.com/photocells */ | |
int photocellPin = 0; // the cell and 10K pulldown are connected to a0 | |
int photocellReading; // the analog reading from the sensor divider | |
int LEDpin = 11; // connect Red LED to pin 11 (PWM pin) | |
int LEDbrightness; // | |
void setup(void) { | |
// We'll send debugging information via the Serial monitor | |
Serial.begin(9600); | |
pinMode(LEDpin, OUTPUT); | |
} | |
void loop(void) { | |
photocellReading = analogRead(photocellPin); | |
Serial.print("Analog reading = "); | |
Serial.println(photocellReading); // the raw analog reading | |
// LED gets brighter the darker it is at the sensor | |
// that means we have to -invert- the reading from 0-1023 back to 1023-0 | |
//now we have to map 0-1023 to 0-255 since thats the range analogWrite uses | |
if (photocellReading > 120) | |
{ | |
digitalWrite(LEDpin, HIGH); | |
} | |
else | |
{ | |
digitalWrite(LEDpin, LOW); | |
} | |
delay(100); | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment