Page 155 - Making PIC Microcontroller Instruments and Controllers

SE'TING OUT OUR DESIGI{ INTEIIT I47

INFORMATION
NEEDED
lnlbnnaiion needed includes:

I LCD datasheets that came wirh the LCD
I The PIC 16F877A datashcct (or rhe datasheer
lbr the I 6F84)
We will go through the softwafe a stcp at a time, and whcn done. il will be your job
to clerD up the softi\'aro and speed p irs operadon-fof exa ptc. to optinize ir for rhc
' '
Inidurunrfoller nu $ ill u.e ir or I nroj.(r,
)
)
We must pick a specific display to work with so we can delelop rerl working soft
wafeforit. Thedisplay Ipicked sclls 1br$6 or soandis available wirh a darasbcet li.om
All Elecironics. AZ Displays also sells one that scems ro be identicat called Model
ACM 1602K. The short tbnn darasheers are sinilar. but the AZ onc is in a crisp pDF
fomat ilnd can be downloaded from thcir Web site for frec. Doing so will mean you
can have this informalion open in a wi dow on your compulcr.
First, rve need !o investigate how nrany pins we willneedon our PIC nicrocontrollcr
to iDleract with our display. This is sunnmrized in Tablc 9.3.

PIN NO. SYMBOL LEVEL DESCBIPTION
ANO NOTES
1 VSS OV Ground for loglc supp y
2 VDD 5.0v Logic power supply, regulaied
3 VO LCD contrast. Can be grounded
RS H/L H: Daia code L: Inskuclion code
5 H/L H: Bead mode L:Wlite mode- Can be
tied low in hardware
6 E H, H>L Enable signal, pulsed ifom H 10 L. Hod
at ll.
7 DBO H/L Dala bil 0
DB1 HIL Data blt 1
D82 HIL Data bil2
1 0 D83 HIL Daia bit 3
t l D84 H/L Data bit 4
12 D85 H/L Data bii 5
1 3 D86 H/L Dala bit 6
DB7 u/L Dala l7
b
BL 5.0 Plus 5V Power lor back lighting lhe

BL Gnd Grcund lor back llghllng power.