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57 lines
1.5 KiB
C++
57 lines
1.5 KiB
C++
/*
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Conditionals - If statement
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This example demonstrates the use of if() statements.
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It reads the state of a potentiometer (an analog input) and turns on an LED
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only if the LED goes above a certain threshold level. It prints the analog value
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regardless of the level.
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The circuit:
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* potentiometer connected to analog pin 0.
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Center pin of the potentiometer goes to the analog pin.
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side pins of the potentiometer go to +5V and ground
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* LED connected from digital pin 13 to ground
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* Note: On most Arduino boards, there is already an LED on the board
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connected to pin 13, so you don't need any extra components for this example.
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created 17 Jan 2009
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modified 30 Aug 2011
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by Tom Igoe
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This example code is in the public domain.
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http://arduino.cc/en/Tutorial/IfStatement
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*/
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// These constants won't change:
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const int analogPin = A0; // pin that the sensor is attached to
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const int ledPin = 13; // pin that the LED is attached to
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const int threshold = 400; // an arbitrary threshold level that's in the range of the analog input
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void setup() {
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// initialize the LED pin as an output:
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pinMode(ledPin, OUTPUT);
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// initialize serial communications:
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Serial.begin(9600);
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}
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void loop() {
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// read the value of the potentiometer:
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int analogValue = analogRead(analogPin);
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// if the analog value is high enough, turn on the LED:
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if (analogValue > threshold) {
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digitalWrite(ledPin, HIGH);
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}
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else {
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digitalWrite(ledPin,LOW);
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}
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// print the analog value:
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Serial.println(analogValue);
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}
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