| /* | |
| 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 potentiometer goes above a certain threshold level. It prints the | |
| analog value regardless of the level. | |
| The circuit: | |
| - potentiometer | |
| Center pin of the potentiometer goes to analog pin 0. | |
| Side pins of the potentiometer go to +5V and ground. | |
| - LED connected from digital pin 13 to ground through 220 ohm resistor | |
| - 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. | |
| https://www.arduino.cc/en/Tutorial/BuiltInExamples/ifStatementConditional | |
| */ | |
| // 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 | |
| } | |