This instructable shows how to make a simple chair prank using an arduino board and 1Sheeld.

All you need to make this prank: Arduino board, Android phone, Piezoelectric Vibration Sensor.

Feel free to ask any questions in the comments and I'll answer them as best i can. Video below shows the final result:

Step 1: What You Need

Hardware:

Arduino Uno or Mega.

1sheeld

Piezoelectric Vibration Sensor

Android Phone (or IOS).

3 x Connection Wires.

1 x Breadboard.

Software:

1- The Arduino IDE which you can download here

2- Get the 1sheeld Arduino library and the phone app here

PS: make sure to go through the 1sheeld intro tutorial here and how to use 1sheeld with different Arduino boards here (i will be using Arduino Mega for the rest of the tutorial)

Step 2: Wiring and Setup

1.mount the 1sheeld on the Arduino board

2.Make sure the power switch shown above is turned to 5V (for Arduino UNO users) if you're using another Arduino board check here

3.Connect the Piezoelectric Vibration Sensor and the wires as shown in the figure.

Step 3: Software

Simply, the code opens the mp3 file that is selected from the media player sheeld in the 1Sheeld app and that happens only when any you apply pressure on the Piezoelectric Vibration sensor and in our prank that means when someone sits on the sensor which is hidden in your chair (you can change the amount of pressure needed to play the mp3 file as you like).

Upload the attached code and lets move to the next step. Use your 1Sheeld Mobile App (Media Player Shield) to get the signal from the ultrasonic sensor to open the mp3 file. PS: make sure the 1sheeld is in upload mode as seen in the image above.

and also when you make this prank it's better to use any vibration sensor with longer wires than my sensor and that to make it easy to hide the sensor in the chair.