User Manual

Page 18
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 Re-
set button is used
to manually reset
the microcontroller—it
generates a low voltage
level on the microcontrol-
ler’s reset pin. LEDs can be
used for visual indication of
the logic state on two pins (RD4
and RE4). 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 (RD7 and RH3) from logic high (1) to log-
ic low (0). In addition to the onboard ON/OFF
switch, two pads (EXT and PSW) allow you to
connect your own external switch.
03 02 01