Its not hard to hack, make, or obtain a digital pedal solution...
However, the real question is.. what are you using it for?
Any game that requires decent fire rates... will be a big problem for most people. Even drummers need to sit down, use dual pedals, and those pedals are leverage-sprung (Not typical arcade pedals. More akin to a trebuchet -vs- a single axis catapult).
One idea I had was to use a center axis pedal, with 2 leaf switches, 1 on each end. That could be use for aiming in the up/down sections of Discs of Tron. The original spinner is a bit difficult to spin+change vertically. ..at the same time, so this solution could actually improve the control.
For non analog racing games, a digital pedal will work fine. May work ok enough for some analog games too.
On mame, an analog pedal can be used as a digital button as well. May not work like that on all games and emulators however.
You can also fashion a dual mode pedal... where its geared analog, with a leafswitch, or similar, for digital as well.