OLIMEX A20-OLINUXINO-MICRO-4GB User manual
Distributor of Olimex LTD: Excellent Integrated System Limited
Datasheet of A20-OLINUXINO-MICRO-4GB - BOARD ARM LINUX SGL A20 4GB
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Datasheet of A20-OLINUXINO-MICRO-4GB - BOARD ARM LINUX SGL A20 4GB
A20-OLinuXino-MICRO
Open-source single-board
Android/Linux mini-computer
U ER’ MANUAL
Document revision P, December 2015
Designed by OLIMEX Ltd, 2015
All boards produced by Olimex LTD are ROHS compliant
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OLIMEX© 015 A 0-OLinuXino-MICRO user's manual
DISCL IMER
© 015 Olimex Ltd. Olimex®, logo and combinations thereof, are registered trademarks of Olimex Ltd. Other product
names may be trademarks of others and the rights belong to their respective owners.
The information in this document is provided in connection with Olimex products. No license, express or implied
or otherwise, to any intellectual property right is granted by this document or in connection with the sale of
Olimex products.
This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License. To view a copy of
this license, visit http://www.creativecommons.org/licenses/by-sa/3.0/.
This hardware design by Olimex LTD is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported
License.
The software is released under GPL.
It is possible that the pictures in this manual differ from the latest revision of the board.
The product described in this document is subject to continuous development and improvements. All particulars of the
product and its use contained in this document are given by OLIMEX in good faith. However all warranties implied or
expressed including but not limited to implied warranties of merchantability or fitness for purpose are excluded. This
document is intended only to assist the reader in the use of the product. OLIMEX Ltd. shall not be liable for any loss or
damage arising from the use of any information in this document or any error or omission in such information or any
incorrect use of the product.
This evaluation board/kit is intended for use for engineering development, demonstration, or evaluation purposes only
and is not considered by OLIMEX to be a finished end-product fit for general consumer use. Persons handling the
product must have electronics training and observe good engineering practice standards. As such, the goods being
provided are not intended to be complete in terms of required design-, marketing-, and/or manufacturing-related
protective considerations, including product safety and environmental measures typically found in end products that
incorporate such semiconductor components or circuit boards.
Olimex currently deals with a variety of customers for products, and therefore our arrangement with the user is not
exclusive. Olimex assumes no liability for applications assistance, customer product design, software performance, or
infringement of patents or services described herein.
THERE IS NO W RR NTY FOR THE DESIGN M TERI LS ND THE COMPONENTS
USED TO CRE TE 20-OLINUXINO-MICRO. THEY RE CONSIDERED SUIT BLE
ONLY FOR 20-OLINUXINO-MICRO.
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Table of Contents
DI CLAIMER ............................................................................................................. 2
CHAPTER 1: OVERVIEW ........................................................................................ 5
1. Introduction to the chapter ....................................................................................................... 5
1.1 Features ..................................................................................................................................... 5
1.2 Target market and purpose of the board ............................................................................... 6
1.3 Board variants .......................................................................................................................... 6
1.4 Board version used in the manual .......................................................................................... 6
1.5 Organization ............................................................................................................................. 7
CHAPTER 2: ETTING UP THE OLINUXINO BOARD ..................................... 8
2. Introduction to the chapter ....................................................................................................... 8
2.1 Electrostatic and electrical polarity warning ........................................................................ 8
2.2 Requirements ........................................................................................................................... 8
2.3 Powering the board .................................................................................................................. 9
2.4 Prebuilt software .................................................................................................................... 10
2.5 Button functions ..................................................................................................................... 10
2.6 Interacting with the board .................................................................................................... 11
2.6.1 HDMI monitor .............................................................................................................................................. 12
2.6.2 VGA monitor ................................................................................................................................................. 12
2.6.3 H via mini U B cable in Debian ............................................................................................................. 12
2.6.4 H via Ethernet .......................................................................................................................................... 12
2. 6 . 5 LCD display .................................................................................................................................................. 13
2.7 Changing the default image resolution ................................................................................ 13
2.8 Connecting and calibrating a display ................................................................................... 15
2.8.1 Android calibration ...................................................................................................................................... 16
2.8.2 Debian calibration ........................................................................................................................................ 16
2. 9 GPIO under Debian ............................................................................................................... 16
2.10 I2C and SPI under Debian .................................................................................................. 17
2.11 Software support .................................................................................................................. 17
CHAPTER 3: A20-OLINUXINO-MICRO BOARD DE CRIPTION ................. 19
3. Introduction to the chapter ..................................................................................................... 19
3.1 Layout (top view) ................................................................................................................... 19
3.2 Layout (bottom view) ............................................................................................................. 20
CHAPTER 4: THE ALLWINNER A20 EMBEDDED PROCE OR ................. 21
4. Introduction to the chapter ..................................................................................................... 21
4.1 The processor ......................................................................................................................... 21
4.2 Block diagram ........................................................................................................................ 22
CHAPTER 5: CONTROL CIRCUITY ................................................................... 23
5. Introduction to the chapter ..................................................................................................... 23
5.1 Reset ........................................................................................................................................ 23
5.2 Clocks ...................................................................................................................................... 23
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5.3 Power supply circuit .............................................................................................................. 23
CHAPTER 6: CONNECTOR AND PINOUT ...................................................... 24
6. Introduction to the chapter ..................................................................................................... 24
6.1 Communication with the 20 ............................................................................................... 24
6.1.1 U B-OTG communication (NAND firmware repair/update) .................................................................. 24
6.1.2 UART0, UEXT1, UEXT2 interface ............................................................................................................ 26
6.2 SD card connectors ................................................................................................................ 27
6.2.1 D/MMC1 slot .............................................................................................................................................. 28
6.2.2 D/MMC slot ................................................................................................................................................ 29
6.3 PWR jack ................................................................................................................................ 30
6.4 MIC_IN & HE DPHONES connectors .............................................................................. 30
6.5 USB_OTG connector ............................................................................................................. 31
6.6 USB_HOST connector ........................................................................................................... 33
6.7 Ethernet .................................................................................................................................. 34
6.8 HDMI connector .................................................................................................................... 36
6.9 VG connector ....................................................................................................................... 37
6.10 S T connector and power ................................................................................................. 38
6.11 GPIO ports ............................................................................................................................ 39
6.11.1 GPIO-1 (General Purpose Input/Output) 40pin connector** ................................................................ 39
6.11.2 GPIO-2 (General Purpose Input/Output) 40pin connector .................................................................... 40
6.11.3 GPIO-3 (General Purpose Input/Output) 40pin connector .................................................................... 41
6.12 LCD_CON 40pin connector ................................................................................................ 43
6.13 Jumper description .............................................................................................................. 44
6.14 dditional hardware components ...................................................................................... 45
CHAPTER 7: CHEMATIC .................................................................................. 46
7. Introduction to the chapter ..................................................................................................... 46
7.1 Eagle schematic ...................................................................................................................... 46
7.2 Physical dimensions ............................................................................................................... 47
CHAPTER 8: REVI ION HI TORY AND UPPORT ........................................ 48
8. Introduction to the chapter ..................................................................................................... 48
8.1 Document revision ................................................................................................................. 48
8.2 Board revision ........................................................................................................................ 50
8.3 Useful web links and purchase codes ................................................................................... 51
8.4 Frequently asked questions ................................................................................................... 52
8.5 Product support ..................................................................................................................... 56
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CHAPTER 1: OVERVIEW
1. Introduction to the chapter
Thank you for choosing this OLinuXino single board computer from Olimex! This document
provides a user’s guide for the Olimex A 0-OLinuXino board. As an overview, this chapter gives
the scope of this document and lists the board’s features. The document’s organization is then
detailed.
The A 0-OLinuXino-MICRO development board enables code development of applications
running on the A 0 microcontroller, manufactured by Allwinner Technology from China.
OLinuXino is an open-source, open-hardware project and all documentation is available to the
customer.
1.1 Features
The board has the following set of features (please note the difference between the two versions of
the board):
•A 0 Cortex-A7 dual-core ARM Cortex-A7 CPU and dual-core Mali 400 GPU
•1GB DDR3 RAM memory
•4GB N ND FL SH memory (available only on the 4GB version of the board)
•SATA connector with 5V SATA power jack
•Capable of FullHD (1080p) video playback
•Native HDMI connector
• x USB High-speed host with power control and current limiter
•USB-OTG with power control and current limiter
•VGA output on 6-pin 1. 5mm (0.05'') step connector
•100MBit native Ethernet
•Battery connector with battery-charging capabilities
•Audio headphones output on connector
•Microphone input on connector
• x UEXT connectors
•LCD connector compatible with with 4.3'', 7.0'', 10.1" LCD modules from Olimex
•160 GPIOs on three GPIO connectors
•MicroSD card connector
•SD/MMC card connector
•DEBUG-UART connector for console debug with USB-SERIAL-CABLE-F
•GPIO LED
•Battery charge status LED
•KB EEPROM for MAC address storage and more
•10 BUTTONS with ANDROID functionality + RESET button
•4 mount holes
•6-16V input power supply, noise immune design
•PCB dimensions: (5600×3 50) mils ~ (14 . 4×8 .55) mm
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1.2 Target market and purpose of the board
The boards from the OLinuXino family are easy to setup and powerful. It is possible to use them in
almost any application as a host board. They are suitable for embedded programming enthusiasts,
Linux and Android gadget fans (they can just use the board as a media center or fully functional
Linux-PC, for instance) and also professionals (since its low cost makes it very good solution for
application-orientated embedded systems). The main usage of the board is software embedded
development without the urge of understanding perfectly the hardware.
The strong points of the boards are the processor speed, the small form factor and the low price-to-
productivity ratio.
Customers have full access to the technical documentation of the board. The software is released
under General Purpose License and the board is considered open-hardware – all schematics and
board design files are available to the customer under the Creative Commons Attribution-
ShareAlike 3.0 Unported License.
1.3 Board variants
There are two major board variants named: A 0-OLinuXino-MICRO and A 0-OLinuXino-
MICRO-4GB. The 4GB version has a built-in NAND memory suitable for the storage of an
operating system without the need of a SD card. The 4GB version comes with already programmed
Android 4. . image.
The other Olimex boards with close characteristics are the ones with A13 and A10 microcontrollers.
The A13 boards feature a generation older processor but since they have been longer on the market
they have better Linux and Android support. The A10 boards feature single (than A 0) processor
core but they are more energy efficient making them better choices for handheld devices and
devices requiring power efficiency.
For projects and designs that require smaller form factor good alternatives to A 0-OLinuXino-
MICRO are: A 0-OLinuXino-LIME , A 0-OLinuXino-LIME and A 0-SOM-EVB.
1.4 Board version used in the manual
Boards from revisions E and F were used while writing this document. It is possible that they are
outdated so it is always recommended to download the latest sources from the GitHub page of the
board.
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1.5 Organization
Each section in this document covers a separate topic, organized as follows:
–Chapter 1 is an overview of the board usage and features
–Chapter provides a guide for quickly setting up the board and software notes
–Chapter 3 contains the general board diagram and layout
–Chapter 4 describes the component that is the heart of the board: the A 0 – Allwinner
processor
–Chapter 5 is an explanation of the control circuitry associated with the microcontroller
–Chapter 6 covers the connector pinout, peripherals and jumper description
–Chapter 7 provides the schematics and the dimensions of the board
–Chapter 8 contains the revision history, useful links and support information
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CHAPTER 2: ETTING UP THE OLINUXINO BOARD
2. Introduction to the chapter
This section helps you set up the OLinuXino development board for the first time. Please consider
first the electrostatic warning to avoid damaging the board, then discover the hardware and software
required to operate the board.
The procedure to power up the board is given, and a description of the default board behavior is
detailed.
2.1 Electrostatic and electrical polarity warning
OLinuXino is shipped in a protective anti-static package. The board must not be exposed to high
electrostatic potentials. A grounding strap or similar protective device should be worn when
handling the board. Avoid touching the component pins or any other metallic element.
Ensure that your development board gets attached to properly working hardware. For example, it is
common for cheap HDMI monitors to lack grounding. Avoid TVs which have no grounding on their
power supply cable! If you can’t avoid them try to add the grounding yourself, if this is not possible
please use USB-ISO to save your development board from potential over voltage.
If you connect other electrical devices to the A 0 board make sure that they have equal electrical
polarity. For example, when you connect an HDMI cable between a TV and the board it is a good
idea to have them both connected to the same electrical source (to the same utility power socket).
This might be said for a serial cable connected between a PC and the board's DEBUG port.
In rare cases different polarity might cause hardware damage to the board.
2.2 Requirements
In order to set up the A 0-OLinuXino-MICRO optimally one or more additional items may be used.
They might be generally placed in three categories:
Required – items that are needed in order to achieve minimum functionality;
Recommended – items that is good to have in order to be able to interact with the most important
of the features of the board;
dditional – items that provide access to additional features or expand the features of the board.
Required items:
- USB type A to USB mini cable – to connect to a personal computer; used for powering the board
and uploading new Android image to the NAND memory (if your board has 4GB NAND)
- Input device – either a mouse/keyboard or touchscreen LCD
- Output device – either HDMI cable + native HDMI monitor/screen/projector; or USB-SERIAL-
CABLE-F + personal computer (for Linux and/or Android debugging); or OLIMEX LCD (TS)
display + 40-pin CABLE-IDC40-15cm; or A 0-VGA-CABLE + VGA monitor/screen/projector
- SD card with compatible image – if you have the board version with NO additional NAND
memory you will need it to use one of the images available.
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Recommended items:
- External USB hub – to split the USB_HOST mounted on the board; you need that to connect more
USB devices
- External power supply unit – 6-16V DC, 5W required (10V @ 0.5A) – for optimal power
- USB-SERIAL-CABLE-F – for Android/Linux debugging on UART0
- CABLE-IDC40-15cm – cable used for LCD_CON ↔ Olimex LCD display
- Adapter cable for the 6-pin VGA connector to standard VGA 15-pin connector
dditional items include:
- Audio device for HEADPHONES jack
- Ethernet cable for wired Ethernet
- A number of extension modules that can add functionality or interface to the board on the UEXT
connector; these can be explored here: https://www.olimex.com/Products/Modules/
Some of the above-suggested items can be purchased by Olimex, for instance:
SY0612E – reliable power supply adapter 50Hz (for EU) 1 V/0.5A for A 0-OLinuXino-MICRO
SY0612E-CHIN – cheaper power supply adapter 50Hz (for EU) 1 V/0.5A for A 0-OLinuXino-
MICRO
20- ndroid-SD – a tested class 10 micro SD card with the latest (by the time of leaving the
Olimex facilities) official Android release
20-Debian-SD – a tested class 10 micro SD card with the latest (by the time of leaving Olimex
facilities) official Debian Linux release
USB-SERI L-C BLE-F – USB serial console cable female
USB-MINI-C BLE – standard USB type A to USB type mini cable
20-VG -C BLE – adapter from 6-pin connector to 15-pin one
C BLE-IDC40-15cm – cable for LCD to LCD_CON connection
LCD-OLinuXino-4.3TS – low-cost 4.3'' LCD display with touchscreen component – 480× 7
LCD-OLinuXino-7TS – low-cost 7'' LCD display with touchscreen component – 800×480
LCD-OLinuXino-10TS – low-cost 10.1'' LCD display with touchscreen component – 10 4×600
LCD-OLinuXino-15.6 – low-cost 15.6'' LCD display with touchscreen component – 10 4×600
LCD-OLinuXino-15.6FHD – low-cost 15.6'' LCD display with touchscreen component –
19 0×1080
S T -HDD-2.5-500GB – 5GB .5'' SATA hard disk
S T -C BLE-SET – cables that allow the connection of a .5'' hard disk to the board
LUMINIUM-HE TSINK-20×20×6MM – heatsink radiator for better processor heat dissipation
2.3 Powering the board
There are three possible ways of powering A 0-OLinuXino-MICRO-4GB – via external supply
providing 6-16V DC at the power jack, from 5V USB port via USB_OTG connector or from 3.7V
Li-Po battery via the LIPO_BAT. Note that the board consumes around 300mA of current at 1 V
when there are no peripherals connected to the USB hosts, so make sure the power supply is able to
provide at least 500mA before plugging. Depending on your preferred way of powering you might
need additional hardware.
Important: Not all USB ports would be able to provide enough power for the board. Try using
another USB port/USB hub or a cable of higher quality. The best practice is not to count on the mini
USB-OTG as a single power source!
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The preferred way of powering the board is via the PWR jack with 6-16V DC with a power of 5W
(e.g. 6Vx0.8A; 16Vx0.3A). This will make the board fully powered and able to power all the
peripherals connected to it.
Note that when powering the board from the USB_OTG, the power provided might be insufficient
to also power a bigger LCD connected to the LCD_con. However, this power option is capable of
driving the board when using external display connected to the HDMI connector.
The typical consumption of A 0-OLinuXino-MICRO-4GB is between 100mA and 3 0mA
depending on the current load and the power voltage applied.
If the board has entered power-down state you can bring it back without restart using the
PWR_BUT. The PWR_BUT is also used to start the board when powered from a Li-Po battery on
the battery connector.
Sometimes when starting Android it is possible the board to enter battery save mode even before
booting fully. Especially, if you have turned off the board without quick boot mode enabled. In this
case you should press the PWR_BUT for at least 5 seconds which would allow the board to start.
For the European customers we sell two power supply adapters, please check chapter . . We also
sell USB OTG to USB type A cables if you lack such.
The default username/password combination for the default Linux image on the SD card (if
purchased) is: root/olimex.
Note that it is normal that when the board is powered some integrated circuits might appear hotter
than others. This is perfectly normal for some chips – for instance – voltage regulators and the main
processor.
2.4 Prebuilt software
The 4GB board-variant comes with Android 4. . ready to use. The default settings of the software
are followed. The default image works with HDMI monitor and 7'' display.
How we have installed the software? Detailed information might be found in chapter 6.1.1 USB-
OTG communication (NAND firmware repair/update).
2.5 Button functions
The bellow three buttons usually are supported under both Android and Debian:
PWR_BUT – used to perform software turn off, software turn on; used to turn on board when
powered by battery – has to be held down for at least couple of seconds to perform each action
RESET – used for hardware reset of the board – it is not recommended
RECOVERY – used to wake up the board from sleep
The following buttons represent functions in the Android (it is possible that not all Android
applications take advantage of the buttons, in such case the button would serve no purpose for that
application):
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VOL+ – increases the volume
VOL- – lowers the volume
MENU – brings up the main menu
SE RCH – brings up search feature
HOME – shows the home screen; note that HOME is also used to enter bootloader mode for
firmware update
ESC – used to navigate away of a menu
ENTER – to select a choice
It is not recommended to disconnect the power supply (either the USB or the power jack) before
turning off the Android from the either the menus or by holding PWR_BUT system written on the
NAND.
ow to restore the Android image might be found in chapter “6.1.1 USB-OTG communication
(NAND firmware repair/update)”.
2.6 Interacting with the board
The typical and recommended way of interacting with a stand-alone A 0-OLinuXino-MICRO
board is via a serial cable connected to a personal computer. You would probably need a cable
suitable for such a connection due to the fact that most personal computers lack a serial port
nowadays. We distribute such a cable. Even if you already have such a cable or you decide to
purchase it elsewhere it is advisable to check this product page for a reference:
https://www.olimex.com/Products/Components/Cables/USB-Serial-Cable/USB-Serial-Cable-F/
You need to connect the serial cable lines as follows: RX line to UART0-TX pin; TX line to
UART0-RX pin; GND to GND. Make sure that the serial cable is connected to your personal
computer and recognized properly after driver installation.
Then open a terminal program on the serial (COM) port which the cable is associated with.
After everything else is set, you would need to power the board as explained in “ .3 Powering the
board”.
In addition to the serial communication, you might also use one or more of the following mediums
to interact with the board:
1. a monitor via HDMI connector
. a monitor via the VGA connector and a VGA adapter
3. SSH via the mini USB connector trough a mini USB cable
4. SSH with a remote computer via LAN connector
5. a display via LCD_CON connector
More details on each of the connections might be found in the consequent sub-chapters.
Note that not all interface options are available for all images. Furthermore, some of the ways of
interaction are (obviously) not suitable for Android OS. The official Debian image should give you
the most possible options of interfacing the board!
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Using HDMI, LCD_CON or LAN might require additional configurations. Furthermore, it is
possible to corrupt the output settings over those interfaces and, thus, lose the output. In such cases,
you can always use the serial cable USB-SERIAL-CABLE-F as a reliable way to establish
connection to the board.
2.6.1 HDMI monitor
All official Debian and Android images for A 0-OLinuXino-MICRO have HDMI output by default.
The board would work out-of-the-box with a native HDMI monitor.
Make sure to use a tested HMDI cable.
The default HDMI resolution in the official images is 7 0p60 (1 80×7 0p at 60Hz). In order to
change that setting the video output on the LCD display you would need to run a configuration
script (if you use Debian Linux) or download a suitable image (if you use Android). Video output
settings are hard-coded in Android images.
More information about the video output settings and the usage of video settings script might be
found in the next chapter “ .7 Changing the default image resolution”.
2.6.2 VGA monitor
All official Debian images for A 0-OLinuXino-MICRO have the option to for VGA video output
via the 6-pin VGA connector. If you wish to transform the custom 6-pin connector to a standard 15-
pin VGA connector you can either use wires or get a ready adapter called “A 0-VGA-CABLE”.
More information about the video output settings and the usage of video settings script might be
found in the next chapter “ .7 Changing the default image resolution”.
2.6.3 H via mini U B cable in Debian
The latest official Debian Linux image allows the use the USB_OTG connector for SSH connection
without the need of a LAN cable or a serial cable. You can use a mini USB cable connected
between your host PC and the on-board mini USB connector. For connection convenience there is a
DHCP server running specifically for USB0 interface. The DHCP server should give IP address to
the new USB0 interface of your host PC so you can make SSH connection from your PC to the
default board IP address of the USB0 interface – 19 .168. .1.
You can connect to the board using a mini USB cable and an SSH client (if you use Windows you
might use "puTTY", for example) at address 19 .168. .1.
For Windows operating system – upon connection, the board should show up in "Windows Device
Manager" as "RNDIS Ethernet Gadget". You might be asked to install a driver. The drivers can be
found online as "RNDIS driver" (Remote Network Driver Interface Specification). The drivers are
provided by Microsoft and they should be available for every Windows distribution – refer to the
respective files and articles provided by Microsoft on how to install the required drivers.
2.6.4 H via Ethernet
By default the board IP address is 19 .168.1. 54. This allows you to connect to the board using an
SSH client (for example “puTTY”) then you have to use this address. You can change this address
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from /etc/network/interface file.
Note that for internet connection you have to set your gateway address in /etc/network/interfaces
file and you have to set your DNS server in /etc/resolv.conf (for example “nameserver
19 .168.1.1”)
2.6.5 LCD display
One of the ways to interact with the board is via an external display (with or without touchscreen
component). The 40-pin male connector LCD_CON has the typical 0.1'' pin step. All Olimex
displays have corresponding 40-pin male connector. You would only need a 0.1'' female-female
cable for the hardware connection.
In order to get the video output on the LCD display you might need either to run at least once a
configuration script (if you use Debian Linux) or download a suitable image (if you use Android).
Video output settings are hard-coded in Android images
More information about the video output settings and the usage of video settings script might be
found in the next chapter “ .7 Changing the default image resolution”.
2.7 Changing the default image resolution
Depending on the display or the screen you want to use with the A 0-OlinuXino-MICRO, you
might need to apply software changes to the prebuilt Android or Linux image.
The typical OlinuXino user would not need to edit the files, however.
To ease the process of changing the resolution we have compiled a number of ndroid images
for the ndroid users (with hard-coded video output settings). lternatively, for Debian Linux
users, we have provided a shell script that can be executed in order to set preferred video
output and resolution.
For Android that you boot from the NAND memory you would need an image suitable for the
specific resolution. Download locations to such images might be found at the wiki article for the
A 0 board here: https://www.olimex.com/wiki/A 0-OlinuXino-MICRO.
For Linux Debian you would need to execute a shell script to be able to change the resolution. It is
very good idea to use a serial cable for connection to the board from a personal computer since in
this case you are dependent on a video resolution (a cable like USB-SERIAL-CABLE-F). When the
board boots type:
./change_display*
or
./change_display_A 0_OLinuXino.sh
and choose the resolution and the interface (LCD, HDMI or VGA).
The supported resolutions are:
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For LCD:
1. 4.3" (480× 7 )
. 7" (800×480)
3. 10" (10 4×600)
For HDMI:
0. 480i
1. 576i
. 480p
3. 576p
4. 7 0p50
5. 7 0p60
6. 1080i50
7. 1080i60
8. 1080p 4
9. 1080p50
10. 1080p60
For VGA: (note that the VGA signals are routed to custom 6 pin connector and you need to from
adapter to standard VGA connector, Olimex also sells such adapter cables)
0. 1680×1050
1. 1440×900
. 1360×768
3. 1 80×10 4
4. 10 4×768
5. 800×600
6. 640×480
7. 19 0×1080
8. 1 80×7 0
If you decide to edit the configurations yourself the easiest way would be to do it on the board. This
can be done offline too (manipulating the image located on the microSD card via a microSD card
reader).
The tools for script.bin changing are located in /opt/sunxi-tools directory:
#cd /opt/sunxi-tools
#./chscr.sh
This will convert script.bin file from sdcard to script.fex file and the file will be opened using nano
editor. Now you can change the board modules and parameters, save the changes ("CTRL"+"X";
confirm with "Y") and exit ("CTRL"+"X" again) from nano editor.
#./wrscr.sh
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this will convert script.fex to script.bin and the script.bin file will be written to the microSD card.
reboot
Reboot the board and the new settings would be enabled.
Alternatively, you can do the changes on the microSD card off the board. You would need to
remove the microSD card and explore it in a microSD card reader. You would need to edit the
configuration file script.bin and edit the settings inside. This file is usually located in Script.bin can't
be opened in the binary format so you would need to convert it to .fex file format first. There are
ready-to-use tools that convert script.bin <-> script.fex. Note that script.bin/fex contains
configuration settings and definitions not only for the video output but also for the pin descriptions
and names; power setting and much more. If you really want to modify and customize the default
images (to change port functions, port names, to disable specific peripherals) you would need to be
able to edit the script files. Please refer to the following web page for more information:
http://linux-sunxi.org/Fex_Guide
2.8 Connecting and calibrating a display
One of the ways to interact with the board is via an external display (with or without touchscreen
component). The 40-pin male connector LCD_CON has the typical 0.1'' pin step. All Olimex
displays have corresponding 40-pin male connector. You would only need a 0.1'' female-female
cable for the hardware connection.
All LCD displays made by Olimex have at least a 0.1'' LCD connector. Going for an LCD output
you would also need need and a cable to attach the display to the board. The cable is sold separately.
The displays recommended for the board at the moment of writing might be found in the table
below:
Display name Size of
display
in inches
Native
resolution
in pixels
Official
Debian image
support
Official
Android image
support
Link to product
page
LCD-OlinuXino-4.3TS 4 3 480×272 Yes No Product page
LCD-OLinuXino-7 7 800×480 Yes Yes Product page
LCD-OLinuXino-7TS 7 800×480 Yes Yes Product page
LCD-OLinuXino-10 10 1 1024×600 Yes Yes Product page
LCD-OLinuXino-10TS 10 1 1024×600 Yes Yes Product page
LCD-OLinuXino-15.6 15 6 1366×768 Yes No Product page
LCD-OlinuXino-15.6 HD 15 6 1920×1080 Yes No Product page
The displays whose names contain “TS” - include a resistive touch screen component.
The cable used for connection depends on the specific board you are using and more specifically it
depends on the pitch of the LCD connector of the board. We have two cables – both 40-pins ones
but one for the bigger pitch (0.1'') and the other for the smaller one (0.05''). Each of the displays
listed in the table above has two connectors suitable for both cables:
CABLE-IDC40-15cm – 15cm long cable suitable for 0.1'' step connectors – Product page
CABLE-40-40-10CM – 10cm long cable suitable for 0.05'' step connectors – Product page
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2.8.1 Android calibration
Calibrating a display under Android is pretty straightforward from the Android application.
Important: initially the boards are calibrated for a specific display and resolution. If you re-write the
image (no matter whether the SD card or the NAND memory) you might need to use a mouse to
calibrate the display initially. It might be impossible to calibrate it only by using the touch
component over the display.
2.8.2 Debian calibration
The command that allows calibrating in Debian Linux is:
ts_calibrate
The default Debian setup is made with settings for HDMI 7 0p/60Hz. If you want to change some
other LCD, VGA or HDMI resolution then you have to start script file in /root directory.
If the problem is under Debian Linux make sure you are properly logged in the LXDE interface!
Else applying calibration would not happen for the current user – if you are calibrating from the X
graphical interface make sure that you are logged as user “olimex” (if calibrating without the X, the
user is “root”).
#su olimex
enter the password: olimex
calibrate the touch screen and reboot the board
#sudo reboot
2.9 GPIO under Debian
You can read data from a given GPIO port. The logical ranges are usually as follows:
0V-1V for LOW (or 0)
.4V-3.3V for HIGH (or 1)
All voltages are measured against ground (GND).
If the input signal is to high, you will at least destroy the port!
The algorithms for writing a value to a GPIO port and reading such a value are pretty similar. The
usage of GPIO ports follows the algorithm (we would use GPIO #49 for demonstration purposes):
1. Export GPIO 49:
echo 49 > /sys/class/gpio/export
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Note that you can export GPIOs in range with:
for i in `seq 1 1 230`; do echo $i > /sys/class/gpio/export; done
. Set input/output GPIO 49
.1 Set input:
echo "in" > /sys/class/gpio/gpio49_ph9/direction
. Set output:
echo "out" > /sys/class/gpio/gpio49_ph9/direction
3. Set value or read value GPIO 49
3.1 Set value:
echo 0 > /sys/class/gpio/gpio49_ph9/value
echo 1 > /sys/class/gpio/gpio49_ph9/value
3. Read input:
cat /sys/class/gpio/gpio49_ph9/value
4. Unexport GPIO 49 when finished
echo 49 > /sys/class/gpio/unexport
A very good document on GPIO usage might be found here:
http://www.py6zgp.com/download/A 0-GPIO.pdf – the document was created by Dr. Guido Pelz.
2.10 I2C and PI under Debian
I C and SPI are both supported in the latest Debian releases. There is respective kernel support for
both. There is a python module called pyA 0 might be found here:
https://pypi.python.org/pypi/pyA 0
At the same web address you would also find a set of examples on how module is used.
2.11 oftware support
We maintain Linux and Android images for SD card which might be downloaded for free and
modified as the user wishes. The latest images and updates are featured at the wiki article of the
device: https://www.olimex.com/wiki/A 0-OLinuXino-MICRO.
We usually try to provide details on how to build the Linux and the Android images at our
wordpress page: http://olimex.wordpress.com/.
Another useful place is the Olimex forums where a lot of people share their experience and advice:
https://www.olimex.com/forum/
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Additional Android and Linux support and features are added overtime. The Linux support is a
work-in-progress and you should not expect full Linux support after the initial volume of such
boards have become available on the market. If you are in a hurry consider the older OLinuXino
designs (which have almost everything supported, have examples available and so on).
You are more than welcome to send or share your suggestions and ideas at our e-mail, the public
forums or irc channel. We would attempt to help in almost every case. We listen to the feedback and
if the majority of users suggest a software change or update we try to implement such. Customer
feedback is very important for the overall state of the software support. However, do not expect full
Linux or Android software support.
We can share our experience. We can give you full details for things we have tried. We can point
you to a resource or a guide. We can give you general directions to solving a specific problem or
places to look for more information. However, we won’t install a piece of software for you or write
custom program for you. We won't provide a specific software solution to a specific software
problem.
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CHAPTER 3: A20-OLINUXINO-MICRO BOARD DE CRIPTION
3. Introduction to the chapter
Here you get acquainted with the main parts of the board. Note the names used on the board might
differ from the names used below to describe them. For the actual names check the A 0-
OLinuXino-MICRO board itself.
3.1 Layout (top view)
The picture below shows the initial revision of A 0-OLinuXino-MICRO. Please note that the
NAND memory is present only in the 4GB version of the board.
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