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
EasyAVR
USB
4
EasyAVR4 User
’
s Manual
MikroElektronika
Development
tools
6
6
page
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SS
SWITCHES
The EasyAVR4 development board features a number of peripherial devices. In order to
enable these devices before programming, you need to check if appropriate jumpers or
switches have been properly set. Switches are devices that have two positions - ON and
OFF, which have a role to establish or break a connection between two contacts. The
EasyAVR4 development board has three groups of switches.
The first group,
SW1,
enables connections between the microcontroller port with analog
capabilities (PORTA) and external pull-up/down resistors. The pull-up/down resistors
should be disconnected from the analog input pins, otherwise they will affect the input volt-
age level. When PORTA pins are used as digital inputs/outputs, the appropriate pull-
up/down resistors should be enabled.
The second group,
SW2,
is used to enable LEDs connected to PORTA, PORTB, PORTC
and PORTD. For example, if the switch for PORTB is OFF, all PORTB LEDs will be turned
off.
The upper four switches of
SW3
are used to enable SPI communication for interfacing with
MMC card. The lower four switches of
SW3
are used to enable the 7-segment displays. If
you don’t need the 7-segment displays in your project, these switches should be OFF.
Switch is ON
Switch is OFF
1
ON
4
3
2
58
7
6
Figure 2.
Group of 8 switches
Switch 1 is ON, and other
switches are OFF
