This is a heart beat counter, which displays the result on an LCD, it amplifies the signal by a dual op amp IC, and passes it to msp, as an interupt to count the number of pulse for 15 secs, it uses internal clock, so its not so accurate, but it will give you a good precised result...
i have given all the neccassary information, including the schematic, the video link, and the code, with the header file..
here is its video...
see the instructions to build it at
http://www.instructables.com/id/Heart-Beat-Counter-using-MSP430/
lcd.h
main.c