Page 14
Figure 4-1:
Two LEDs, two buttons
and a reset button
4. Buttons and LEDs
The board also contains a
01
reset button
and a pair of
02
buttons and
03
LEDs,
as well as an ON/OFF switch. The
Reset button is used to
manually reset the
microcontroller—
it generates
a low voltage
level on the
microcontroller’s reset
pin. LEDs can be used
for visual indication of
the logic state on two pins
(GPIO156 and GPIO157). An
active LED indicates that a logic high
(1) is present on the pin. Pressing any
of the two buttons can change the logic
state of the microcontroller pins (GPIO032
and GPIO113)) from logic high (1) to logic low
(0). In addition to the onboard ON/OFF switch,
two pads (EXT and PSW) allow you to connect
01
03
02
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
