Slot machine spin down rate

Projects Programming
2
  1. initialize it with a random speed;
  2. exponentially decay it down to a threshold; keep count of how long it takes to go down to that threshold;
  3. random generate a number between 0..1;
  4. if that number if >= 0.5, round up / or down the count;
  5. all the time, display that count.

It should be fairly simple.