diff --git a/piezosensor b/piezosensor
new file mode 100644
index 0000000..c051637
--- /dev/null
+++ b/piezosensor
@@ -0,0 +1,29 @@
+const int ledPin = 13;      // LED connected to digital pin 13
+const int knockSensor = A0; // the piezo is connected to analog pin 0
+const int threshold = 100;  // threshold value to decide when the detected sound is a knock or not
+
+
+// these variables will change:
+int sensorReading = 0;      // variable to store the value read from the sensor pin
+int ledState = LOW;         // variable used to store the last LED status, to toggle the light
+
+void setup() {
+  pinMode(ledPin, OUTPUT); // declare the ledPin as as OUTPUT
+  Serial.begin(9600);       // use the serial port
+}
+
+void loop() {
+  // read the sensor and store it in the variable sensorReading:
+  sensorReading = analogRead(knockSensor);
+
+  // if the sensor reading is greater than the threshold:
+  if (sensorReading >= threshold) {
+    // toggle the status of the ledPin:
+    ledState = !ledState;
+    // update the LED pin itself:
+    digitalWrite(ledPin, ledState);
+    // send the string "Knock!" back to the computer, followed by newline
+    Serial.println("Knock!");
+  }
+  delay(100);  // delay to avoid overloading the serial port buffer
+}