Page 59 - Making PIC Microcontroller Instruments and Controllers

CFEATII{G OUTPUTS 49

which is provided on rhe LAB-XI, and then move on ro using the speaker anal an R/C
hobby servo.
"luming
Lefs start with tlrc standard an LED ON and OFF, program. We will use
one of the LEDS in the ren LED bargraph tharis provided on the LAB,XI. We have
control of only the eight righlrnosr LEDS on this bargraph. The lefmost LED is thc power
ON indicator and the one rcxr to it cones ON if we were using a common calhocle
affangement for the bargraph (as opposed to the common anode an aigemen! as it is cur
rently configured).
Thc cirouitry we are inrerestcd in is shown in Figure 5.1. AI other circuitry of the
ir so
LAB X I is still in place, but we have suppressed we are not distracted by it and can
concentrate on the LED that is of interest to us. (PORTD.o). PORTD.0 refers to bit 0 oI
PORTD.
In our lirst exercise, we want ro control rhe rightmosr LED of the LED array. This is
connected to bit 0 of PORTD in the circuirry showD in Figure 5. L Our progran needs
to tum this LED ON ard OFF !o demonstrale thar we have complere conrrol of rhese

5

3
io

1 5 26

Flgurc 5.t The LED bargraph chcuilry for POBTD pin O.