mirror of https://github.com/noisymime/Arduino.git
35 lines
1.4 KiB
Plaintext
35 lines
1.4 KiB
Plaintext
/* Knock Sensor
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* by DojoDave <http://www.0j0.org>
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*
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* Program using a Piezo element as if it was a knock sensor.
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*
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* We have to basically listen to an analog pin and detect
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* if the signal goes over a certain threshold. It writes
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* "knock" to the serial port if the Threshold is crossed,
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* and toggles the LED on pin 13.
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*
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* http://www.arduino.cc/en/Tutorial/Knock
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*/
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int ledPin = 13; // led connected to control pin 13
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int knockSensor = 0; // the knock sensor will be plugged at analog pin 0
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byte val = 0; // variable to store the value read from the sensor pin
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int statePin = LOW; // variable used to store the last LED status, to toggle the light
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int THRESHOLD = 100; // threshold value to decide when the detected sound is a knock or not
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void setup() {
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pinMode(ledPin, OUTPUT); // declare the ledPin as as OUTPUT
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Serial.begin(9600); // use the serial port
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}
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void loop() {
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val = analogRead(knockSensor); // read the sensor and store it in the variable "val"
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if (val >= THRESHOLD) {
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statePin = !statePin; // toggle the status of the ledPin (this trick doesn't use time cycles)
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digitalWrite(ledPin, statePin); // turn the led on or off
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Serial.println("Knock!"); // send the string "Knock!" back to the computer, followed by newline
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}
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delay(100); // we have to make a delay to avoid overloading the serial port
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}
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