Hi,
If you count pulses, with interrupts, and you calculate every second, you only have to multiply the count by 60 to get RPM, and you can do it ALL in integer.
Have to written code that just outputs to the serial port, forget your display stuff?
Just write some code that JUST inputs the pulses and converts them to RPM and displays on the serial port.
If you wrote the code in stages you should have been through this stage.
OR did you try and write it ALL at once?
Tom... 