This application is a counter sampling over a 10s period.  Data is multiplied
by 6 to give a per minute output on the display.

Timer 1 is configured to give an interrupt every 0.5s.  After 20s the input count 
over the period is read, multiplied by 6 and displayed on the LCD.

The input is on RB0.  The count is a +ve edge triggered signal which cause a 
interrupt. The input is via a schmitt trigger and worked with a aquare, triangular 
and sine wave.  If a low level signal is provided then a amplifier may be needed.  
The checksum of the code is 5F5F and was created with the Microchip ICD1.
