The headband you mentioned is called a haptic compass. I have seen it done
with 12 motors and a belt. It uses a compass IC or a magnetometer. I just completed
a haptic compass design that was built into a neck-strap.
Ah yeah that was it - I suppose it doesn't matter where the feedback motors are placed as long as it's consistent...
Have you done any testing with yours? Have you found that you've 'learnt' from it?
For the motors we used pager motors. You will need transistor buffers to drive
the motors but any ATmega board can drive the transistors. All of the low-cost
pager motors I have seen are around 75mA. In my design we only activated one
motor at a time to save the battery. If you cycle between the motors fast enough
you will not be able to perceive the cycling.
Excellent thank-you - I have seen some vibrating motors but pager ones sound smaller - do you have any advice as to where I can get these? (I shall Google in a mo...).
I would like to be able to vary the speed of the 'application' based on user input (variable pot) - this way once the user is acclimatised they can increase the speed, or rather shorten the pauses, between each number.