[Kevin Sevcik]

Does it looks like your wheel is turning at 247 RPM? That's about 4 revs per second. Max period wouldn't help with the 30k blip. That's why I added a minimum period check in my RPMCounter class to ignore any period values that were obviously too small. Max period will help if your feedback is going from some number like 100 straight to zero. or flashing between 0 and 100. That's the counter thinking the wheel hast stopped and sending a 0 for period, then sending a good value when it sees the next pulse. Less likely to happen on your setup since you have 6 screw heads.

The 30k problem might be your screwheads. The GTS might be picking up the small gap in the screwhead for the flathead screwdriver. Using a hex-head fastener or something without the gap in the middle would probably work better.