I really like to design my own USB peripherals to make them more "attractive" ;)

With some friends, we had the idea to use a real slingshot to play Angry Birds instead of using a standard mouse! The objective is to plug the slingshot into a computer over USB and to kill pigs with it!

The problem is that we had to find a microcontroller or a little board with a USB controller and a USB library already developed. Quite recently, Mbed has published a USB device library which is able to emulate a bunch of peripherals.

Combining the two previous ideas, we decided to design a real slingshot using an Mbed connected to a computer over USB to play Angry Birds!

Take a look at the video!

With a real slingshot, you tilt the slingshot and stretch sling. The idea to measure these was using:
   - An accelerometer - this can measure the tilt by tracking the gravity vector (which way is down!)
   - A rubber stretch sensor - this can be used as the sling, and measure how much it is stretched

The slingshot was crafted by Chris Jarratt, from a branch found in Epping Forest, London! This is the structure in to which I embedded all the electronics.

Step 1: What do you need to realize your own Mbed slingshot ?

- The main element is an Mbed. We are using the new LPC11U24 mbed but you can use the LPC1768 mbed instead

- A piece of wood in order to build the slingshot. I advice you to know a good carpenter ;) Take a look at Chris website

- Then you need some sensors to detect angle and strength:
    - 3-axis accelerometer for the angle: ADXL345. You can easily read accelerometer data as an mbed library is available to use it
    - A stretch sensor for the strength. We use this flexible cord which the resistance changes when stretched. To use this sensor, you also need a 10k resistor in order to read a voltage in a voltage divider circuit

- Two pin header sockets to plug the mbed

- A USB type B connector

- A USB cable A to B to connect the mbed to a computer

- A solder iron

- A breadboard

- A veroboard

I think it would be pretty cool to incorporate some of this tech into an actual slingshot. Perhaps laser guided... *strokes chin thoughtfully*
nice project, so creative
@virsing:<br>Nice to see someone who tried the slingshot!!<br>Yes it's mine developed with the mbed team
Saw and played it today on the &quot;embedded world conference&quot; in N&uuml;rnberg Germany, its awesom :-D<br>was it yours?
Hats off, sir!
Great project, and I liked the video!

About This Instructable


13 favorites


More by samux: How to make an Mbed USB slingshot ?
Add instructable to: