Using the TI LaunchPad from your KoP

[jhersh]

Originally Posted by ayeckley

We've determined that the likely cause is due to use of a polled-input approach. The default code for the Launchpad-FRC polls at 10ms, but at a realistic knob-turning rate the rising edges of the ticks from Phase A can occur at ~5ms apart. Anyone see a problem there? By switching to an interrupt-based approach and a reasonably tightly-coded ISR we expect to resolve the issue [hopefully] without screwing up the interrupts used in the serial communications process.

If you only decode in 1X mode (rising edge on A only) then you have 1/4 the interrupts to process. Seems pretty doable. Polled input had better have plenty of headroom to be reliable, but you've already discovered that.