This project combines an Emic 2 text- to- Speech module, a ultrasonic Ping))) distance sensor, the MAKE compressed air rocket launcher, and an Arduino Uno.
This project could be used for security, pranks, and many more fun things.

Step 1: Materials

You will need to acquire the following materials:

- Arduino Uno R3 (x1)

- Breadboard (x1)

- Emic 2 (Rev. A) Text- to – Speech module (x1)

- PING))) Ultrasonic Distance Sensor (x1)

- Jumper Wires

- NPN transistor (MP 2222A) (x1)

- 100 Ohm resistor (x1)

- 8 AA battery holder (x1)

- AA batteries (x8)

- 9V battery clip (x1)

-8 Ohm speaker (x1) (not shown)

- Compressed Air Rocket Launcher (from Makershed) (x1)

- Bicycle pump (x1)

- Paper rocket

Step 2: Emic 2 Connections

1) Place the Emic 2 on the breadboard, and connect the anode and cathode of the 8 Ohm speaker to ( SP--) and (SP+) pins on the Emic 2.

2) Connect the (SIN) pin of the Emic 2 to digital pin 3 of the Arduino, and the (SOUT) pin of the Emic 2 to digital pin 2 of the Arduino.

3) Connect the Emic 2 to the 5V and GND rail on the breadboard.

Your connections should look something like in the picture.

Step 3: Ping))) Connections

1) Connect the (5V) and (GND) pins to the voltage rail on the breadboard, and connect the voltage rail with the Emic 2 and Ping))) power inputs attached to the (5V) and (GND) pins on the Arduino.

2) Connect the (SIG) in of the Ping))) to digital pin 7 on the Arduino

The connections with the Emic 2 and Ping))) should look something like in the picture.

Step 4: Transistor Connections

1) Place the Transistor into the breadboard. MAKE SURE THE BULKY SIDE OF THE TRANSISTOR IS FACING YOU!!!, This is to make sure that you are placing the wires where you are supposed to.

2) Connect the rightmost pin of the transistor to the voltage input of the rocket launcher and to the unused (GND) pin of the Arduino.

3) Connect the middle pin of transistor to the 100 Ω resistor, and connect the resistor to digital pin 12 of the Arduino.

4) Connect the leftmost pin of the transistor to the positive wire of the 8AA battery pack (with the 9V battery clip)

5) Lastly, connect the negative wire of the 8AA battery pack (with the 9V battery clip) to the negative input of the rocket launcher

The transistor connections (without Emic 2 and Ping))) ) should look like this picture.

Step 5: Code for Arduino

Copy the attached document for the Arduino into the Arduino IDE and upload it to your board.

1) The code first establishes an environment in which it will run and other important information it will need later in the program.

2) In the setup() function, the program sets up the Emic 2, and other variables to be used later in the program.

3) In the loop() function, the program first checks the distance with the ping))) sensor, then calls another function called check(), this function checks if the distance is less than the limit or greater than the limit and then performs what it is asked to do.