It will all depend on what sort of Mat you are using. There are xtras to grab the inputs of joysticks, serial devices, usb devices, etc, so use the appropriate xtra and you can get the buttons pushed... see here for a list of xtras:
That's a rather large list ha ha,
I can't find anything that'll go with my dance pad though.
If it helps, it is a USB one that's was for Playstation? I think MAC have usb overdrive but I have found no alternatives for windows.
I have used the USBAccessXtra by Geoff Smith to get access to USB devices, including the PS3 controller (the standard one, not a dance pad). I would give that a shot.
@stopherr : I'm trying to achieve the same thing! I would like to use a dance pad (USB) and simulate a keyboardEvent on flash!
So far, I'm thinking to buy this pad http://www.positivegaming.com/index.php?id=36
and then use an external small program to transform the signal into a keyboardEvent : http://glovepie.org/glovepie.php
The constructor of the pad told me that it installs itself as a standard Windows / Mac HID.
Let me know if you found something interesting.
im trying to do the same thing too! i think im wanting to use unity tho, im making a game for my uni project and want the dance pad to control the characters movements but im lost and have know clue what to do, do you have any tips??