User Manual

Page 11
mikroBUS
™
standard specications mikroBUS
™
add-on board standard
T
he large number of mutually compatible mikroBUS
™
add-on boards is the key value of
this standard. Each one carries a single IC or module that brings a specic functionality
to a target mainboard. New add-on boards enhance the existing range and provide more
choice to end-users. To simplify their use and standardize their appearance, when creating
mikroBUS
™
add-on boards, designers should adhere to a few requirements in regard to the size,
layout and silkscreen markings.
T
GND NC NC NC RX TX NC NC
GND 3V3 NC NC NC NC RST DEF
4
1
1. When a module uses an interface
already featured on mikroBUS
™
, use
those exact pins and mark them
accordingly. This is the default layout:
2. When a pin is not used, it
should be marked NC (for
Not Connected)
3. When there’s no overlap be-
tween the name or function
of a given mikroBUS
™
pin
and the pin on the module,
the silkscreen should spell
the name of the pin from
the module. (In this exam-
ple, DEF is in place of the
default AN pin.)
4. Some add-on boards can
have a separate pinout in
addition to mikroBUS
™
.
These are usually marked
by their function, here GPIO.
The pinout on a mikroBUS
™
add-on board corresponds with the module, not the target mainboard.
As such, some pins are left unused and some deviate from the default conguration as seen on
the mikroBUS
™
socket. Four cases should be considered.
Pinout specication
sockets RX TX MISO MOSI
boards TX RX SDO SDI
2
3
Note the dierences: UART markings
are criss-crossed because receivers
are matched to transmiters. SPI
markings are abbreviated. Like so:
Example add-on board