Mikroe EasyAVR PRO v8 User manual

E a s y A V R P R O v 8 M a n u a l
P A G E 1
D E V E L O P M E N T B O A R D f o r 8 / 16 b i t A V R ® m i c r o c o n t r o l l e r s
EasyAVR PRO v8
U S E R M A N U A L

P A G E 2
E a s y A V R P R O v 8 M a n u a l
It’s time to rethink the way you approach rapid prototyping
Let us introduce you to the latest generation of MIKROE development boards – E a s y A V R P R O v 8
Time-saving embedded tools

All images shown in the manual are for illustration purpose only.
Introduction 5
Development board overview 6
Power supply unit 8
Detailed description 8
PSU connectors 9
Power/debug, USB-C connector 9
Power 12VDC, external power supply 9
Battery power supply 10
Power redundancy and uninterrupted power supply (UPS) 10
Powering up the development board 11
Dual power supply 11
CODEGRIP – programmer/debugger module 12
DBG selection 13
Connectivity 14
SiBRAIN 16
INPUT/OUTPUT section 18
EXPANDED ports 18
PORT buttons 18
BUTTONS DIP switch 18
UP-PULL-DOWN switch 18
PORT LEDs 18
2x5 pin headers 19
2x20 display connector 20
1x16 display connector 21
mikroBUS™sockets 22
Click boards™23
Communication 24
USB-UART 24
USB 24
Additional GNDs 25
What’s Next? 30
Table of contents

EasyAVR PRO v8 is a development board designed for rapid development of embedded
applications. Redesigned from the ground up, it offers broad set of standard, as well as several
unique features never seen before in the world of embedded electronics: programming and
debugging over WiFi network, support for a large number of high pin count 8/16 bit AVR®
microcontrollers by Microchip, regardless of their pin number, and more.
The development board is designed so that the developer has everything that might be needed,
following the Swiss Army knife concept: a highly advanced programmer/debugger module, a
powerful and clean power supply module, a huge set of connectivity options including USB,
UART, as well as set of MIKROE proprietary standards and technologies, including the well-
established mikroBUS™ standard, a standardized SiBRAIN socket, and a standardized 2x20
display connector. A number of interactive options is also available, including buttons, LEDs,
switches, and more... All these features are packed on a single development board, which itself
uses innovative manufacturing technologies, delivering fluid and immersive working experience.
EasyAVR PRO v8 development board is also an integral part of the MIKROE rapid development
ecosystem. Natively supported by the MIKROE Software toolchain, backed up by hundreds of
different Click board™designs with their number growing on a daily basis, it covers many different
prototyping and development aspects, thus saving precious development time.

E a s y A V R P R O v 8 M a n u a l
P A G E 5

P A G E 6
E a s y A V R P R O v 8 M a n u a l
O V E R V I E W
Development
board overview
The EasyAVR PRO v8 development board features a clean and intuitive layout,
allowing the user to instantly understand how to set it up and how to easily tune
it according to needs. The development board is divided into several sections,
arranged so that all the related interactive components such as switches, buttons,
indicators, and connectors, are logically positioned and grouped together. Each
section of the development board contains components important for a reliable
operation of the board itself. The Power Supply Unit (PSU), the CODEGRIP
programmer/debugger module, and five mikroBUS™sockets are located at the
upper section of the development board. This is where the microcontroller unit
(MCU) is powered from, programmed, and interfaced with various Click boards™.
The PSU module provides a clean, regulated voltage for the development board.
It can use a wide range of external power sources, including a battery, an external
12V power supply, and a power source over the USB Type-C (USB-C) connector.
It supports the power OR-ing function for uninterrupted operation. The onboard
PSU module regulates, filters, and distributes the power across all the connected
peripherals. The development board is equipped with two touch-sensitive buttons
labeled as POWER and RESET. These buttons are used to power up the board and
reset the MCU. Their sleek design and flawless responsiveness add up to the whole
experience. These touch-sensitive buttons are resistant to wear over time and do
not exhibit any bouncing effect, unlike mechanical switches.
The powerful CODEGRIP module supports a wide range of different high pin count
8/16 bit AVR® MCUs, produced by Microchip. It allows in-place programming
and debugging of all supported microcontrollers, seamless integration with the
MIKROE software environment, and some powerful and unique features such as
the programming/debugging over WiFi; a feature that will revolutionize the way
that the embedded applications are developed.
The CODEGRIP module uses the USB-C connector for a reliable and secure
connection with the personal computer (host PC). It does not require any
additional drivers because it utilizes an HID driver model, natively supported by the
computer's operating system (OS). The USB-C connector is also used to power
the development board, simplifying the cable management.

E a s y A V R P R O v 8 M a n u a l
P A G E 7 O V E R V I E W
EasyAVR PRO v8 offers five improved mikroBUS™sockets, allowing interfacing
withavastamountofelectroniccircuitsandreferencedesigns,standardizedunder
the Click board trademark. Click boards™are simple to use, require no additional
hardware configuration and can be easily connected to the development board
by inserting them into any of the available mikroBUS™sockets. A new design of
the mikroBUS™socket allows even easier interfacing with the Click board™line of
products: it has a sturdier design which helps aligning the Click board™ correctly.
To read more about development improvements and huge benefits offered by the
mikroBUS™and Click board™line of products, visit the official MIKROE web page
at www.mikroe.com
EasyAVR PRO v8 development board is equipped with two display connectors,
located in the middle section of the board. One connector is a single row 16-pin
header which supports 2x16 characters Liquid Crystal Display (LCD) in 4-bit mode,
offering an optional PWM backlight driving feature. The second display connector
is a standardized 2x20-pin female socket, which supports a vast number of display
boards, featuring different display modules, such as TFT Board line of products.
TFT Board displays come in different sizes, they support various resolutions, and
they feature different capabilities. All these display boards can be easily mounted to
the existing connector offering complete freedom of choice. For more information,
please visit the official MIKROE web page at www.mikroe.com
The I/O (Input/Output) section occupies the lower part of the development board
and contains available MCU pins routed to 2x5-pin headers for easy access. All of
them are equipped with configurable pull-up or pull-down resistors, buttons for
applying logic states to MCU pins, and LED indicators. Pins are divided into groups
following the grouping concept used on the MCU itself. This section is where the
most interaction with the MCU takes place.
Communication options such as USB-UART and USB DEVICE are also included.
The respective USB and USB-UART connectors are positioned at the edges of the
development board, so they can be easily accessed. This is also true for the power
connectors, as well as for the external programmer/debugger connector. This
allows clean and clutter-free cable management.
EasyAVR PRO v8 development board is supported by a powerful CODEGRIP Suite,
offering complete control over the EasyAVR PRO v8 development board. It is
used to intelligently manage programming and debugging tasks, and to configure
various other options and settings, providing visual feedback through its clean and
comprehensive Graphical User Interface (GUI). To better understand how to operate
and configure EasyAVR PRO v8 development board and its integrated CODEGRIP
module, a separate manual is provided at www.mikroe.com/manual/codegrip

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E a s y A V R P R O v 8 M a n u a l
1
2
3
4
P O W E R S U P P L Y
P A G E 8
Figure 1: Power supply unit view
Power supply unit
The power supply unit (PSU) (1) provides clean and regulated power, necessary
for proper operation of the development board. The host MCU, along with the
rest of the peripherals, demands regulated and noise-free power supply.
Therefore, the PSU is carefully designed to regulate, filter, and distribute the
power to all parts of the development board. It is equipped with three diff erent
power supply inputs, offering all the flexibility that EasyAVR PRO v8 needs,
especially when used on the field. In the case when multiple power sources are
used, an automatic power switching circuit with predefined priorities ensures
that the most appropriate will be used.
The PSU also contains a reliable and safe battery charging circuit, which allows
a single-cell Li-Po/Li-Ion battery to be charged. Power OR-ing option is also
supported, providing uninterrupted power supply (UPS) functionality when an
external or USB power source is used in combination with the battery.
The digitally controlled programmable voltage output can be used as a voltage
reference for various purposes, including A/D or D/A converters, comparators,
and other peripherals that require or can use an external reference voltage.
The programmable voltage output can be controlled over the CODEGRIP Suite.
Detailed description
The PSU has a very demanding task of providing power for the host MCU and
all the peripherals onboard, as well as for the externally connected peripherals.
One of the key requirements is to provide enough current, avoiding the voltage
drop at the output. Also, the PSU must be able to support multiple power sources
with different nominal voltages, allowing switching between them by priority. The
PSU design, based on a set of high-performance integrated devices produced by
Microchip, ensures a very good quality of the output voltage, high current rating,
and reduced electromagnetic radiation.
At the input stage of the PSU, the MIC2253, a high-efficiency boost regulator IC
with overvoltage protection ensures that the voltage input at the next stage is well
regulated and stable. It is used to boost the voltage of low-voltage power sources
(a Li-Po/Li-Ion battery and USB), allowing the next stage to deliver well-regulated
3.3V and 5V to the development board. A set of discrete components are used to
determine if the input power source requires a voltage boost.
(1) This image is only for demonstration purpose, please do not
remove the PSU plastic cover nor touch any of the components below.
The development board can be permanently damaged.


E a s y A V R P R O v 8 M a n u a l
P A G E 9 P O W E R S U P P L Y
When multiple power sources are connected at once, this circuitry is also used to
determine the input priority level: externally connected 12V PSU (2), power over
USB (3), and the Li-Po/Li-Ion battery (4). The transition between available power
sources is seamless, providing uninterrupted operation of the development board.
The next PSU stage uses two MIC28511, synchronous step-down (buck)
regulators, capable of providing up to 3A at their output. The MIC28511 IC utilizes
the HyperSpeed Control®and HyperLight Load®architectures, providing an ultra-
fast transient response and high efficiency for light loads. Each of the two buck
regulators is used to supply power to the corresponding power supply rail (3.3V
and 5V), throughout the entire development board and connected peripherals.
Power 12VDC, external power supply
An external 12V power supply can be connected over the DC barrel connector,
labeled as POWER 12VDC (2). When using an external power supply, it is
possible to obtain an optimal amount of power, since one external power
supply unit can be easily switched for another, while its power and operating
characteristics can be decided per application. The development board
allows maximum current of 3A per power rail, when using an external 12V
power supply.
The development board will be able to maintain its operating voltages within
the specified limits, as long as the voltage of the external power supply stays
within the range stated below, in the table. Having in mind all the additional
peripherals that can be connected to the development board, as well as their
power consumption, the external power supply should be considered as a
primary power source, especially for the most power demanding applications.
Power/debug, USB-C connector
The development board can be powered over the USB-C connector, labeled
as POWER/DEBUG (3). This connector provides power from the USB host,
USB power bank, or USB wall adapter. When powered over the USB connector,
the available power will depend on the source capabilities.
Maximum power ratings, along with the allowed input voltage range in the
case when the USB power supply is used, are given in the table Figure 2.
N O T E
If the host PC is not equipped with the USB-C connector, a Type A to
Type C USB adapter may be used.
Figure 2: USB Power supply table
USB Power Supply
Input Voltage [V] Output Voltage [V]
3.3
5
3.3 & 5
1.8
1.4
0.8 & 0.8
5.94
7
6.64
Max Current [A] Max Power [W]
MIN
4.4 5.5
MAX
When using PC as a power source, the maximum power can be obtained
if the host PC supports the USB 3.2 interface, and is equipped with USB-C
connectors. If the host PC has a USB 2.0 interface, it will be able to provide
the least power, since only up to 500 mA (2.5W at 5V) is available from the
host in that case.
Note that when using long USB cables or USB cables of low quality, the voltage
may drop outside the rated operating voltage range, causing unpredictable
behavior of the development board.
PSU connectors
As explained, the advanced design of the PSU allows several types of power
sources to be used, offering unprecedented flexibility: when powered by a
Li-Po/Li-Ion battery, it offers an ultimate degree of autonomy. For situations
where the power is an issue, it can be powered by an external 12VDC power
supply, connected over the 5.5mm barrel connector. Power is not an issue
even if it is powered over the USB cable. It can be powered over the USB-C
connector, using power supply delivered by the USB HOST (e.g. personal
computer), USB wall adapter, or a battery power bank.
There are three power connectors available, each with its unique purpose:
POWER/DEBUG, USB-C connector (3)
BATTERY, standard 2.5mm pitch XH battery connector (4)
POWER 12VDC, barrel type male 2mm x 6.5mm power connector (2)

P A G E 10
E a s y A V R P R O v 8 M a n u a l
P O W E R S U P P L Y
Battery Power Supply
Input Voltage [V] Output Voltage [V]
3.3
5
3.3 & 5
1.6
1.2
0.7 & 0.7
5.28
6
5.81
Max Current [A] Max Power [W]
MIN
3.5 4.2
MAX
Figure 4: Battery Power Supply table
Using USB hubs, long USB cables, and low-quality USB cables, may
cause a significant USB voltage drop, which can obstruct the battery
charging process.
Battery power supply
When powered by a single-cell Li-Po or Li-Ion battery, the development board offers
an option to be operated remotely. Combined with the fact that the board can be
remotely programmed and debugged over the WiFi network, the EasyaAVR PRO v8
development board allows complete autonomy, allowing it to be used in some very
specific situations: hazardous enviroment, agricultural application and etc.
The battery connector used on the development board is a 2.5mm pitch XH
connector. It allows a range of Li-Po and Li-Ion batteries to be used. The
development board offers battery charging functionality from both the USB
connector, and the external power supply. The battery charging circuitry of
the PSU module manages the battery charging process, allowing the optimal
charging conditions and longer battery life. Charging process is indicated by
a CHARGER LED indicator. The battery charging current can be configured by

N O T E When connecting an external power supply over a barrel connector,
make sure that the polarity of the barrel connector is matched with its
counterpart on the development board, according to the image printed
next to the male DC connector.
N O T E It is advised to disable the battery charging circuitry if there is no battery
connected to the EasyAVR PRO v8 development board. This can be done
using CODEGRIP Suite. For more information, please consult the CODEGRIP
manual on the following link: www.mikroe.com/manual/codegrip
Maximum power ratings, along with the allowed input voltage range in the
case when the external power supply is used, are given in the table Figure 3.
Figure 3: External Power supply table
External Power Supply
Input Voltage [V] Output Voltage [V]
3.3
5
3.3 & 5
2.8
2.8
2.8 & 2.8
9.24
14
23.24
Max Current [A] Max Power [W]
MIN
10.6 14
MAX
using the CODEGRIP Suite, which offers a choice between 100mA and 500mA
when the USB power supply is used, or between 100mA and 200mA, when
the external 12V power supply is used. In the case when the EasyAVR PRO
v8 development board is powered down, the charging current will be set to
500mA by default (200mA with the external power supply).
If both the external 12V power supply and the USB cable are connected to the
development board, the battery will be charged from the external 12V power
supply, thus minimizing the USB power consumption.
Maximum power ratings at fully charged battery, along with the allowed input
voltage range when the battery power supply is used, are given in the table
Figure 4.
Power redundancy and uninterrupted
power supply (UPS)
The PSU module supports power supply redundancy: it will automatically
switch to the most appropriate power source if one of the connected power
sources fails or becomes disconnected. The power supply redundancy also
allows for an uninterrupted operation (e.g. UPS functionality, the battery will
still provide power if the USB cable is removed, without resetting the MCU
during the transition period).

E a s y A V R P R O v 8 M a n u a l
P A G E 11
1 2
Figure 4: Battery power supply connection
Dual power supply
EasyAVR PRO v8 development board supports both 3.3V and 5V power supply
on a single board. Advanced PSU module provides the possibility to chose
power supply for board and host MCU, between 3.3V (default) and 5V. This
setting can be easily configured from CODEGRIP Suite, and this feature
greatly increases the number of supported MCUs.
To easily indicate the power supply configuration, the previously mentioned
POWER LED will also have a dual function. It lights up GREEN when 3.3V power
supply is configured, and lights up BLUE when 5V power supply is chosen.
Powering up the development board
Two touch-sensitive buttons are used to power up and reset the EasyAVR
PRO v8 development board. These capacitive buttons are processed by
two AT42QT1011, digital burst mode charge-transfer sensors, specifically
designed for human-machine interfaces (HMI), from Microchip. The
AT42QT1011 allows very responsive and reliable touch detection for the
connected button pad.
As soon as a valid power source is connected, the development board will
enter the Stand-By mode. When the capacitive POWER button is pressed, the
PSU module will start distributing the power to the rest of the development
board. This is indicated by the POWER LED indicator, located on the PSU
module itself.
Right under the POWER LED, there is a CHARGE LED, indicating the charging
status of the Li-Po/Li-Ion single cell battery, if connected. The complete
battery power supply section, including the battery charger circuit, is
explained in the respective chapter of this manual.
Below the POWER capacitive button (1), there is a RESET capacitive button
(2) which is not entirely power-related, but it has a similar function: it is routed
to the MCLR pin of the MCU, allowing the RESET function to be performed.

P A G E 12
E a s y A V R P R O v 8 M a n u a l
NET-LINK (AMBER) When the CODEGRIP module is connected to the WiFi
network, this LED will indicate that the connection has been established
ACTIVE (RED) Indicates the operational state of the CODEGRIP module: when
CODEGRIP module is in the bootloader mode, this indicator will blink. Normal
operation of the CODEGRIP module is indicated by the ACTIVE LED being
constantly turned ON
DATA (BLUE) Indicates that there is a data transfer ongoing between the MCU
and the CODEGRIP module
The onboard CODEGRIP module (1) requires no additional drivers, as it
utilizes a HID driver model, which is natively supported by the computer OS.
This makes its installation very easy and straightforward in the case when
the USB cable is used. As soon as the USB cable is connected to the host PC,
the CODEGRIP module is enumerated and the development board is ready to
be used.
CODEGRIP module is supported by CODEGRIP Suite. Detailed explanation
on how to configure and use the CODEGRIP module on the EasyAVR PRO
v8 development board, can be found in the CODEGRIP manual, and can be
downloaded on the following link: www.mikroe.com/manual/codegrip
CODEGRIP
programmer /
debugger module
Envisioned as the unified development platform, EasyAVR PRO v8
development board is equipped with the onboard CODEGRIP programming/
debugging module, which supports various high pin count 8/16 bit AVR®
MCUs, produced by Microchip. The CODEGRIP module can be interfaced with
the host computer over the USB-C connector.
Besides the USB cable, the CODEGRIP module (1) can be accessed over
the WiFi network. This is a revolutionary new feature, which allows some
unique usage scenarios, currently not available on any other programming/
debugging solution in the world. The WiFi connectivity option of the
CODEGRIP module offers a complete autonomy of the development board.
Running in hazardous environment while debugging the software in real
time, programming the MCU with a new software during exposure, having the
sensor responses collected and logged remotely from several different base
points, debugging a drone firmware while it is in mid-air... These are just a
simple examples of what EasyAVR PRO v8 development board can offer.
CODEGRIP module is equipped with LED indicators that provide visual
feedback about its status:
POWER (GREEN) indicates that the development board is powered on
USB-LINK (YELLOW) After the host OS completes the USB enumeration of the
CODEGRIP module, this LED will indicate that the connection has been established
C O D E G R I P

E a s y A V R P R O v 8 M a n u a l
P A G E 13
DBG selection
The EasyAVR PRO v8 development board is equipped with the RJ-45
connector (2), allowing an external programmer/debugger to be connected.
The connector supports a wiring pinout compatible with Microchip®ICD
external programmers/debuggers. In adition, there is a 1x8 male pin
header, with a wiring pinout compatible with Microchip® PICkit 4 external
programmers/debuggers.
The DIP switch located next to the RJ-45 connector allows control of the
interface between onboard CODEGRIP module and target MCU:
ONBOARD (down): Interface is enabled. If an external debugger probe-
device is connected, there is a possible collision in communication.
EXTERNAL (up): Interface is disabled. External debugger probe-device can
reliably communicate with target MCU. 1Figure 5: Programmer/debugger view
NC
VDD
GND
TDO/MISO/DATA
TCK/SCK
RST
TDI/MOSI
TMS
RJ-45
EXT PROG/DBG PINOUT
1. TDI/MOSI
2. NC
3. VDD
4. GND
5. TDO/MISO/DATA
6. TCK/SCK
7. RST
8. TMS
2

P A G E 14
E a s y A V R P R O v 8 M a n u a l
CONNECTIVITY
Connectivity
C O N N E C T I V I T Y
One of the key features of the EasyAVR PRO v8 development board is its connectivity.
It features a diverse amount of connecting options, making the board very versatile, adaptable to any
situation, and very easy to work with.
It has two display connectors (1x16 LCD connector and 2x20 display connector), USB-UART, USB HOST/
DEVICE, an external programmer/debugger connector and many more. The PORT I/O section is the most
distinctive connectivity option, which takes up the entire lower half of the board. It allows direct connection
to the available MCU pins. This section also contains LEDs for visual indication of pin states, BUTTONS
for applying the desired logic states to the pins, and DIP switches for configuring pull-up or pull-down
resistors.
All the LEDs, buttons, and headers are logically organized and grouped as PORTS, following the pin
organization topology of the MCU.
The presence of five standardized mikroBUS™sockets is something that makes the EasyAVR PRO v8
development board very special: the world of Click boards™is now just under your fingertips. By combining
up to 5 different Click boards™, virtually an unlimited number of combinations is possible, considering the
fact that the Click board™repository already has several hundreds of various Click boards™, with more
added on a daily basis.
Tight integration of the EasyAVR PRO v8 board with the whole MIKROE ecosystem, allows seamless and
effortless prototyping, and truly rapid embedded application development. For more info about the
mikroBUS™standard and the Click board™line of products, please visit the official MIKROE web page at
www.mikroe.com

E a s y A V R P R O v 8 M a n u a l
P A G E 15 C O N E C T I V I T Y
Easily create an IoT Weather Station with
the EasyAVR PRO v8 development board.
Use the following tools:
∫G2C click
∫OLED C click
∫Temp-Log 2 click
∫Thunder click
∫LPS22HB click
∫EasyAVR PRO v8 development board
∫SiBRAIN for ATmega
∫TFT Board 5

Figure 6: Main board with SiBRAIN socket view
2
SiBRAIN
Due to SiBRAIN add-on board universal nature, EasyAVR PRO v8 development
board supports a vast number of different MCUs.
In addition, each of the supported MCUs has some specifics, such as the
number of pins and ports, additional peripherals, clock speeds, etc.
Therefore, the MCU is supplied in a form of a standardized SiBRAIN card.
It can support MCUs with various number of pins and specific hardware
requirements. Such a modular approach allows flexibility in selecting the
MCU type, regardless of its pin number or specific hardware requirements.
The SiBRAIN card itself contains two 168-pin mezzanine connectors
providing support for MCUs with a very high pin count, as well as for additional
electronic components, necessary for a proper operation of the MCU. One
connector is a female connector (1), while the other is a male connector (2).
The development board is likewise, equipped with a pair of complementary
connectors, eliminating any possibility of incorrect orientation and placement
of the SiBRAIN card.
Besides these two connectors, an SiBRAIN card can also include multiplexing
circuits, crystal oscillators/clock generators, voltage filtering capacitors, and
some other MCU-specific components, necessary for reliable operation.
1

E a s y A V R P R O v 8 M a n u a l
P A G E 17 C O N N E C T I V I T Y
Before you plug the SiBRAIN card into the socket, make sure that the
power supply is turned off. Check the SiBRAIN card orientation so it
matches the printed outline of the SiBRAIN card on the development
board. Place the SiBRAIN card so that both connectors are properly
aligned with their onboard counterparts. Then gently press down the
SiBRAIN card, if there is a physical resistance, please do not try to force
the SiBRAIN card into the socket.

Figure 7: SiBRAIN card back and front view
13 26 5 4
N O T E The picture shown is for illustration purpose only. Actual SiBRAIN card
may vary depending on the installed MCU.
This makes each SiBRAIN card self-contained unit, allowing the development
board to operate on a logic level, not having to facilitate specific requirements
of many different MCUs. This also allows the MCU to be freely chosen,
not having to worry about the pin compatibility and similar issues. Most
importantly, it allows very simple swapping between different MCU types
during the development phase, without any hardware interventions.
From the top side, each SiBRAIN card has a clearly labeled MCU type it is
designed for (SiBRAIN for ATmega), as well as its PORT width, printed just
below the MCU type label (8-BIT PORT) (3).
In addition, pins are grouped in accordance to mikroBUS™sockets to which
they are routed. Therefore, there are 5 groups of pins. The pins labeled with
yellow color (4) belong to mikroBUS sockets, while the white labels (5)
represent corresponding pins on the MCU.
On the bottom side of the SiBRAIN card, users can find the hardware revision
number of the card itself (6).

P A G E 18
E a s y A V R P R O v 8 M a n u a l
C O N N E C T I V I T Y
INPUT / OUTPUT section
In general, I/O pins of any MCU are internally grouped as PORTs. Such pin
grouping scheme is kept throughout the development board as well, offering
a clean and organized interface.
EXPANDED ports
There is a total of ten 8-bit ports, ranging from PORTA to PORTK (PORTI excluded).
All ten ports are EXPANDED PORTS, located at the lower left and right side of the
board (1), each containing a set of eight buttons, eight LEDs, a single eight-pole
DIP switch, and a single 2x5 pin header with 2.54mm pitch. These EXPANDED
PORTS are labeled according to the MCU PORT they are routed to.
PORT buttons
Port buttons can be used to apply the desired logic state to pins of the MCU
PORT they are routed to. These buttons are small tactile SPST switches that
work in conjunction with a DIP switch, labeled as BUTTONS (2) (also labeled
as SW5 on the schematic – seperatly included). This DIP switch is located in
the BOARD SETUP section (3).
BUTTONS DIP switch
This ten-position (poles), tri-state DIP switch, allows the button to apply a LOW
logic level to an MCU pin when pressed (connecting it to a reference GND), or to
apply a HIGH logic level when pressed (connecting it to the power rail). It can also
completely disconnect the button, preventing accidental button presses. To limit
the pin current and prevent the excessive inrush of currents when a button is
pressed, a protective 220Ωresistor is used, connected in series with the switch.
Each position of the BUTTONS DIP switch is used to determine the applied logic
level of a button press for the entire PORT, there are ten poles on this DIP switch,
allowing control of all ten groups of buttons.
UP position: a button applies HIGH logic level to the corresponding PORT pins
(according to 8-bit labeling)
MID position: a button is completely disconnected
LOW position: a button applies LOW logic level to the corresponding PORT
pins (according to 8-bit labeling)
UP-PULL-DOWN DIP switch
Besides the buttons, each of the ten EXPANDED PORTS has a single eight-pole,
tristate DIP switch (4), labeled as UP-PULL-DOWN (SW7 through SW14 on the
schematic – seperatly included), used to enable a pull-up or a pull-down resistor
for the specific pin, or to leave the specific pin in a floating state:
UP position: connects a 4.7 kΩresistor between the MCU power rail and the pin
associated with the particular DIP switch position (a pin is pulled-up)
MID position: disables both pull-up and pull-down resistor connections from the
pin associated with the particular DIP switch position, leaving it in a floating state
DOWN position: connects the 4.7 kΩ resistor between the GND and the pin
associated with the particular DIP switch position (a pin is pulled-down)
PORT LEDs
Each PORT contains a group of eight LEDs (5), used to visually indicate a
logic state of the specific pin. The maximum current through a single LED is
limited with the 4.7k resistor. Each LED is connected to a PORT pin and it is
labeled according to the pin’s name.
LEDs on each PORT can be disabled, when they are not needed. Having a LED on
a communication line or an A/D converter input might alter expected results,
since LED represents an additional electrical load on a particular pin.
There is a DIP switch with ten positions (poles), with each pole assigned to a
specific PORT. This DIP switch is labeled as PORT LEDS (6) on the development
board (SW4 on the schematic). A single DIP switch position is used to disable
a group of LEDs which belong to a PORT:
ON position (up): enables LEDs for a specific PORT, associated with the
particular DIP switch position
OFF position (down): disables LEDs for a specific PORT, associated with the
particular DIP switch position

E a s y A V R P R O v 8 M a n u a l
P A G E 19
Figure 8: I/O ports view
C O N N E C T I V I T Y
23
5
47
4
51
1
76
2x5 PIN HEADERS
Besides LEDs, there are also 2x5 pin headers (7) in EXPANDED PORT sections.
All the pins which belong to a specific PORT are routed to the 2x5 pin header
located in that PORT section, along with the GND and the power rail.
These 2x5-pin headers can be used to expand the connectivity of the EasyAVR
PRO v8 development board, allowing interfacing with other devices, peripherals,
and measurement equipment, either by using IDC10 extension cables, IDC10
female sockets, or simply by using jumper wires. Enhanced connectivity is one
of the key features of EasyAVR PRO v8 development board, there are many
connectivity options provided. However, 2x5-pin headers allow the most extensive
connectivity as they expose all the available GPIO MCU pins to the outside world.

P A G E 20
E a s y A V R P R O v 8 M a n u a l
2x20 display connector
EasyAVR PRO v8 development board features a standardized 2x20-pin display
connector (1). This connector consists of the 8080 parallel interface, offering
support for displays with up to 8 bits per color (up to 24-bit mode, 16 million
colors). Besides the 8080 interface, this connector also contains pins related to
touch panel controller, interfaced over dedicated I2C bus lines. The power supply

Make sure to turn off the power supply before placing the display
module on the board. Otherwise, the display module or the board can
be permanently damaged.
rails are also routed to this connector. Using the standardized pinout ensures
compatibility with the existing (i.e. TFT Board Capacitive line of displays), as well
as the future versions of display boards. More information can be found at
www.mikroe.com/accessories/displays/tft-displays
1Figure 9: 2x20-pin board connector view