| /* |
| Conditionals - If statement |
| |
| This example demonstrates the use of if() statements. |
| It reads the state of a potentiometer (an analog input) and turns on an LED |
| only if the LED goes above a certain threshold level. It prints the analog value |
| regardless of the level. |
| |
| The circuit: |
| * potentiometer connected to analog pin 0. |
| Center pin of the potentiometer goes to the analog pin. |
| side pins of the potentiometer go to +5V and ground |
| * LED connected from digital pin 13 to ground |
| |
| * Note: On most Arduino boards, there is already an LED on the board |
| connected to pin 13, so you don't need any extra components for this example. |
| |
| created 17 Jan 2009 |
| modified 9 Apr 2012 |
| by Tom Igoe |
| |
| This example code is in the public domain. |
| |
| http://arduino.cc/en/Tutorial/IfStatement |
| |
| */ |
| |
| // These constants won't change: |
| const int analogPin = A0; // pin that the sensor is attached to |
| const int ledPin = 13; // pin that the LED is attached to |
| const int threshold = 400; // an arbitrary threshold level that's in the range of the analog input |
| |
| void setup() { |
| // initialize the LED pin as an output: |
| pinMode(ledPin, OUTPUT); |
| // initialize serial communications: |
| Serial.begin(9600); |
| } |
| |
| void loop() { |
| // read the value of the potentiometer: |
| int analogValue = analogRead(analogPin); |
| |
| // if the analog value is high enough, turn on the LED: |
| if (analogValue > threshold) { |
| digitalWrite(ledPin, HIGH); |
| } |
| else { |
| digitalWrite(ledPin,LOW); |
| } |
| |
| // print the analog value: |
| Serial.println(analogValue); |
| delay(1); // delay in between reads for stability |
| } |
| |