59 lines
1.7 KiB
C++
59 lines
1.7 KiB
C++
/*
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LED bar graph
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Turns on a series of LEDs based on the value of an analog sensor.
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This is a simple way to make a bar graph display. Though this graph
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uses 10 LEDs, you can use any number by changing the LED count and
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the pins in the array.
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This method can be used to control any series of digital outputs
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that depends on an analog input.
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The circuit:
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* LEDs from pins 2 through 11 to ground
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created 26 Jun 2009
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by Tom Igoe
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modified for Maple
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by LeafLabs
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http://www.arduino.cc/en/Tutorial/BarGraph
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*/
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// these constants won't change:
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const int analogPin = 0; // the pin that the potentiometer is attached to
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const int ledCount = 10; // the number of LEDs in the bar graph
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int ledPins[] = {
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2, 3, 4, 5, 6, 7, 8, 9, 10, 11 }; // an array of pin numbers to which LEDs are attached
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void setup() {
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// set up analogPin for analog input:
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pinMode(analogPin, INPUT_ANALOG);
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// loop over the pin array and set them all to output:
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for (int thisLed = 0; thisLed < ledCount; thisLed++) {
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pinMode(ledPins[thisLed], OUTPUT);
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}
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}
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void loop() {
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// read the potentiometer:
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int sensorReading = analogRead(analogPin);
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// map the result to a range from 0 to the number of LEDs:
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int ledLevel = map(sensorReading, 0, 4095, 0, ledCount);
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// loop over the LED array:
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for (int thisLed = 0; thisLed < ledCount; thisLed++) {
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// if the array element's index is less than ledLevel,
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// turn the pin for this element on:
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if (thisLed < ledLevel) {
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digitalWrite(ledPins[thisLed], HIGH);
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}
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// turn off all pins higher than the ledLevel:
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else {
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digitalWrite(ledPins[thisLed], LOW);
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}
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}
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}
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