Imagine the following: you are getting interested in RC vehicles so you want to try it out. You decide to build a small indoor hovercraft. After doing some research you head over to your favorite Chinese web-shop to buy some parts. And here it becomes interesting.

This situation happened to me some time ago. Adding all the items I needed I built up the whole list of components in the cart:

• 2x Brushless outrunner motor - $8.14
• 2x 30A ESC - $6.84
• 1x Battery - Already lying around
• 2x Propeller - $2.09
• 1x RC transmitter - $24.03
• 1x RC receiver - $5.01

I was quite shocked at the price of the transmitter and receiver. Wouldn't there be a cheaper solution to this? I did not need the long range of these transmitters. Something simple for indoor use would be good enough. The possibility to also be able to use it for some upcoming robotics projects would make it even better.

And then it got to me! Utilizing something everybody already has to do the hard work: a mobile phone.