Page 210 - Making PIC Microcontroller Instruments and Controllers

206 COUt{tlxG PUI.SES! A PiOOMn ABIE TACHOMETER

gXW Code for using the 4 seven'segment displays (Confitued)
get value !o show
inhibits lhe decinal Poinl
PORfB=VALuE I z nakes walue and z select one segrnent
z-(z<<Lr+t go !o nex! seemenc
PAT'SEVS P pause to show segmenl
NEXIT II
cfear PoRTB to Prevent ghosting
PAUSEUS P pause to show clear
BEIIT'RN end of subroutine

END end all ptoerrans viLh end
Here is another way in wbich I maale the tachometer after I needed a boad that could
be useal as a base for all kinds of devices. I designed this board as a unive$al all-
purpose board for my experiments. I have since improved the board and have been very
happy with the results. It saved me much time and sped up the many expenments I had
to make to write this book.
Figures 15. 12 and 15.1 3 show the use of a flexible board that suppofts the use of both
4 seven-segment displays ard that of a 2-line-by-20-character display All the wiring
to both types of devices is in place Thjs elimhates mosl of the tedious wiring that has
to be alone on almost all prcjects. On these cards, all the VO bas been left unconnected

SffiW Anolher wey to make the tachometer/pulse counter' lronl