Please send comments to Roger (arnans@media.mit.edu)
The do-it button is simply a switch. So, any switch will work (including the Lego touch sensors). The car will determine that the button is pressed when the sensor value is less than approximately 500.
The button
described here uses a Lego electric plate and a key-switch. The electric
plate can be ordered from the Lego site.
The part number is 5037 ($5.99 for nine multiple-size pieces). I ordered the
key-switch from digi-key. The part
number is SW411-ND ($0.30 each).
The two pieces are soldered together. I used a clipper to expose the contacts of the electric plate. Please test the orientation of the key-switch before soldering.
