decoding quadrature encoders

[cbrun17]

Hi Richard,

Not sure why my last post went in twice... Sorry.

When I added the mcu context save routine the display crashed. It will ~ work if I move the shaft slowly, however, moving quickly caused the code to trip over itself and lockup the screen.
My first guess was that when jumping out of the ISR, the next return in the main program uses the most recent return address on the stack and returns to the point the interrupt occurred, crashing the program.

However, I noticed my up/down LED indicators are still operational which suggests the code is still working okay and its either the formatting or calculations that are causing some latency. if I perform a display reset, the counting resumes normally.

So I made two changes which seem to have resolved the issue.

I removed the two LCD defines:
DEFINE LCD_COMMANDUS 2000 ' Set Command Delay time in uS
DEFINE LCD_DATAUS 60 ' Set Data delay time in uS

And added a 50ms pause after the display routine to give the display time to settle.

I know there must be a more efficient way to format the display to reduce the number of instructions necessary to accomplish the xx.xx by .25 increment, but this seems to smooth out he results.

Thanks again for you feedback.

Chris