M I K R O E L E K T R O N I K A S O F T W A R E A N D H A R D W A R E S O L U T I O N S F O R T H E E M B E D D E D W O R L D
7
7
page
EasyAVR
USB
4
EasyAVR4 User
’
s Manual
MikroElektronika
Development
tools
JJ
UU
MM
PP
EE
RR
SS
JUMPERS
Jumpers, like switches, can break or establish a connection between two points. Beneath the
plastic cover of the jumper is a metal contact, which makes a connection if the jumper is
placed between two disconnected pins.
For example, the RS232 communication has two jumpers, J11 and J12, used as switches.
They are used to connect or disconnect Rx pin to PD0 and Tx pin to PD1 pin of the micro-
controller. A connection is made when the jumpers are placed between two contacts.
More often jumpers are used as a selector between two possible connections by using a three
pin connector. As illustrated in Fig. 4, the middle contact can be connected to the left or right
pin, depending on the jumper’s position.
Left line
is selected
All lines are
disconnected
Right line
is selected
Jumper is ON
Jumper is OFF
Figure 3.
Figure 4.
Jumper as a switch
Jumper as a
multiplexer
