Page 61 - Making PIC Microcontroller Instruments and Controllers

BLINKEIGHI LEDS l|{ SEOUET{CE 5l

SetTRISD to %l1111110 fi$r to set all lines 1() inputs excepr D0. which is shown as rhe
only pin set to bc an outpur.)
We will usc binary notation ('/.11110000) for setting all pins, pors, port directions,
and rcgister values thro ghout this book, though you can use hexadecimal ($F0) and
decimal (DEC 240) notation interchangeably. Using bindr.y norarion lets you see what
each pin i\ doilg wIhoul hr!ing ln m"le .rn) co ref.ior\.

Blink Ei t LEDs in S uence

ID Program 5-2, we blintr the eight rightmost LEDS on the bargraph, one LED aratime.
The circujtry we are using for this progran is shown in Figule 5.2. We do this by set
ting PORTD to I and then multiplying il by two a toral of eight times to move the lighrcd
LED left one position in each iteration. Nore rhat the last multiplicarion ovcrflows the
ll bit counter and turns all thc LEDS OFF

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LED bargraph chcuihy to all of PORTD.