So here is a nice way to control your next robot by simply tilting your transmitter, that's right no more wiggling the sticks ! Who's idea was to make the sticks so sharp anyways ?
This project is an easy and an inexpensive modificaiton to an existing RC transmitter. You'll need just few off the shelf parts, and you can use one of the many accelerometer break-out boards available (with analog output).
The principle of operation is really simple - the RC transmitter uses a potentiometer for each axis, it acts as a voltage divider sending a voltage of 0..5V (the middle position corresponds to 2.5V) to the analog input that is converted into a pule of 1..2ms that is sent over RF.
This module converts (amplifies and shifts) the accelerometer analog output , usually 1.65 +/- 0.4V to the same range of the potentiometer and sends it to the transmitter instead.
I put together a tutorial how to build it (schematic , and build suggestions included):
http://starlino.com/rc_transmitter_accelerometer.html
Have fun !
https://www.youtube.com/watch?v=U0FaM6A1zDE