A20-OLinuXino-LIME2

A20-OLinuXino-LIME2.jpg

A20-OLinuXino-LIME2 looks similar to both A20-OLinuXino-LIME and A10-OLinuXino-LIME. The major differences between A20-OLinuXino-LIME2 and A20-OLinuXino-LIME are:

  • LIME2 has gigabit Ethernet (GbE), compared to the standard 100Mb Ethernet of the LIME
  • LIME2 design provides double the RAM memory, compared to the LIME design (1024 vs 512)
  • Much better routing of DDR3 memory.
  • Increased the number of layers from 6 in LIME to 8 in LIME2
  • Corrected pinout of the LCD and GPIO connectors (shields designed for the LIME layout are not compatible with the LIME2 layout)


The A10 and the A20 processors are pin-to-pin compatible. Because of the processor, software-wise the board is closer to A20-OLinuXino-LIME than to the A10-OLinuXino-LIME. This resemblance to other designs definitely might speed the development on the board - a lot of software written for A20-OLinuXino-LIME might work out-of-the-box with A20-OLinuXino-LIME2. Additionally, pinout tables, GPIO maps, etc released for A20-OLinuXino-LIME would apply to A20-OLinuXino-LIME2 (except for the 0.05" step connectors - LCD display and all the GPIOs connectors, which have a different layout compared to both A20-OLinuXino-LIME and A10-OLinuXino-LIME).

A20-OLinuXino-LIME2 features:

  • A20 Cortex-A7 dual-core ARM Cortex-A7 CPU and dual-core Mali 400 GPU
  • 1GB DDR3 RAM memory
  • 1 gigabit native Ethernet
  • optional 4GB NAND FLASH memory
  • SATA connector with 5V SATA power jack
  • HDMI FullHD 1080p
  • 2x USB Low-Full-High-Speed hosts with power control and current limiter
  • USB-OTG with power control and current limiter
  • LiPo Battery connector with battery-charging capabilities
  • LCD connector compatible with with 4.3", 7.0", 10.1" LCD modules from Olimex
  • 160 GPIOs on three GPIO connectors
  • MicroSD card connector
  • DEBUG-UART connector for console debug with USB-SERIAL-CABLE-F
  • status LED
  • Battery charge status LED
  • Power LED
  • 2KB EEPROM for MAC address storage and more
  • 2 BUTTONS with ANDROID functionality + RESET button
  • 2 mount holes
  • 5V input power supply, noise immune design
  • PCB dimensions: 84 x 60 mm


Contents

Official Images from OLIMEX

In this chapter you would find links to torrents with the official Debian and Android images. The images in this chapter were compiled by Olimex. They are recommended for beginners and first time users since they include full hardware support. If you are experienced Linux professional you might find useful our build instructions also published here.

The downloaded file xxxx.7z is an archive of xxx.img file. In order to write the image on SD card you have to extract the xxx.7z file.

  • For Linux: use p7zip package. If you don't have 7zip installed first install it

   #apt-get install p7zip

Copy a20_Lime2_debian_second_release.7z file in your directory and unzip the archive with

   #7za e a20_Lime2_debian_second_release.7z

where a20_Lime2_debian_second_release.7z The output should be a new 4GB file with extension img Put 4GB SD card in your card reader and type

   # ls /dev/sd

Then press two times <TAB> you will see a list of your sd devices like sda sdb sdc note that some of these devices may be your hard disk so make sure you know which one is your sd card before you proceed as you can damage your HDD if you choose the wrong sd-device. You can do this by unplugging your sd card reader and identify which "sd" devices remove from the list. Once you know which device is your sdcard like sda use this text instead of the sdX name in the references below:

   #dd if=a20_Lime2_debian_second_release.img of=/dev/sdX

The Debian Linux image is 4GB and the file system can be extended to suit a bigger card. Use the following three commands to execute a script that would use all the free space of your card:

  sudo su
  ./resize_sd.sh /dev/mmcblk0 2
  reboot

Linux images

These official Debian images should be downloaded to a microSD card. You need a properly set torrent client to download the official images - they available only as torrent files. You can install the Debian to the NAND or the eMMC of your board (if it comes with one). Information on booting Debian from the NAND might be found in these wiki articles: how to install Debian to NAND; how to install Debian to eMMC. Download locations for the official images might be found below:

ALWAYS FIRST TEST WITH LATEST OFFICIAL IMAGE, NEWER HARDWARE REVISIONS OF THE BOARD MIGHT NOT WORK WITH OLDER IMAGES!!!


Latest stable official images - Debian 8 (Jessie) Both images are suitable for the standard version A20-OLinuXino-LIME2. However A20-OLinuXino-LIME2-n4GB and A20-OLinuXino-LIME2-n8GB have different image compared to A20-OLinuXino-LIME2-e4GB:

Torrent of official Debian Jessie release #13 for A20-OLinuXino-LIME2, A20-OLinuXino-LIME2-n4GB, and A20-OLinuXino-LIME2-n8GB (not suitable for boards with eMMC flash): A20-OLinuXino-LIME2 Debian Jessie with kernel 3.4.103+ release 13

Torrent of official Debian Jessie release #13 for A20-OLinuXino-LIME2, A20-OLinuXino-LIME2-e4GB (not suitable for boards with NAND flash): A20-OLinuXino-LIME2 Debian Jessie with kernel 3.4.103+ release 13

Image description and typical interfacing: description and basic usage of different peripherals at at the GitHub page

Image build instructions and required files for latest Debian Jessie release might be found here: build instructions and required files at the GitHub page

You can find some older releases and older build instructions (older image revisions might be used as a reference, for testing purposes, or if you own old hardware revision of the board) at the following article: older releases and older build instructions


Note: the A20-LIME2-DEBIAN-SD card which we have in our web store contains the image suitable for board with no flash or board with NAND memory on a 8GB Class10 fast microSD card. The A20-LIME2-eMMC-DEBIAN-SD contains the image suitable for boards with extra eMMC memory. If you want to use our images, please, use card with speed Class10 or higher. Else the Linux performance would be very slow.

Note: in the previous Debian releases the Ethernet was auto-detected and initialized during boot BUT this was causing big delays in the start-up of the board if you didn't want to use Ethernet or if there wasn't Ethernet cable connected.

You can enable it by following these two steps:

1. To check under what name the LAN is associated write "ifconfig –a"

2. If, for example, it is under eth0 name, then write: "dhclient eth0"

This should enable the Ethernet and then SSH would also be available.

Android images

Torrents of official Android releases are below. Please read description of the image carefully.

Newest official release (recommended):

For the NAND flash memory:

Torrent of Android 4.2.2 release 1 for NAND memory (with HDMI and 7 inch 800x480 support - LCD-OLinuXino-7TS): A20-OLinuXino-Lime2 Android for NAND with HDMI and 7 inch display support

Torrent of Android 4.2.2 release 1 for NAND memory (with HDMI and 10 inch 1024x600 support - LCD-OLinuXino-10TS): A20-OLinuXino-Lime2 Android for NAND with HDMI and 10 inch display support

For microSD card:

Torrent of Android 4.2.2 release 2 for 8GB microSD card (with HDMI and 800x480 support): A20-OLinuXino-Lime2 Android for 8GB microSD card with HDMI and 7 inch display support

Torrent of Android 4.2.2 release 2 for 8GB microSD card (with HDMI and 1024x600 support): A20-OLinuXino-Lime2 Android for 8GB microSD card with HDMI and 10 inch display support, this image requires loading via PhoenixSuit, refer to the FAQ section at the end of this page

Torrent of Android 4.2.2 release 1 for 4GB microSD card (with HDMI and 800x480 support): A20-OLinuXino-Lime2 Android for 4GB microSD card with HDMI and 7 inch display support

Build instructions and source files for the official Android images for A20 boards in this repository: https://github.com/hehopmajieh/olinuxino_configs

Notable unofficial images

Below you would find locations to images released by the community. These are not officially supported by Olimex, however, some of these releases are pretty good and worth a try:

  • A20-OLinuXino-LIME2 is supported by openSUSE Factory, installation instructions might be found here: openSUSE wiki link
  • A20-OLinuXino-LIME2 is recognized by the Devuan community and there are official releases here might be found here: Devuan list of files link


Documents

A20-OLinuXino-LIME2 user's manual

User's manual for A20-OLinuXino-LIME2 and A20-OLinuXino-LIME2-4GB

A20 Brief

A20 brief

A20 Datasheet

A20 Datasheet

A20 User Manual

A20 user's manual

Hardware

LIME2 shield templates

Eagle and KiCAD shield templates for LIME2

GPIO description

A20-OLinuXino-LIME2 GPIO description

A template that might be used to create custom shields or own adapters might be downloaded for Eagle or KiCad at the GitHub here: shield template

Power supply and consumption

A20-OLinuXino-LIME2 requires 5V regulated power supply external source. regulated means that the power supply adapter should provide exactly 5V no matter loaded or unloaded (some cheap wallwart adapters are not regulated and under no load their power supply may be higher than 5V although marked as 5V power supply, please measure with voltmeter if your power supply provide 5V as if you connect more than 5V to LIME it will be damaged!!!)

The power jack is standard OLIMEX power jack.

A20-OLinuXino-LIME can be powered from three sources:

  • +5VDC voltage applied PWR jack
  • +3.7V from LiPo re-chargable battery connected to LiPo board connector
  • +5V applied to USB-OTG connector


Power consumption is as follows:

  • LiPo 3.7V power battery: 1.2W
  • +5VDC input power: 1.3W


Comparison table of power consumption might be found at the following link.

LiPo battery allow backup power supply when main power is interrupted. A20-OLinuXino-LIME2 has power managment IC which charge the battery when main power is present, when power is interrupted the LiPo battery automatically provide backup power supply. Step-up converter prvide 5V for the USB peripherials too. For LiPo batteries we recommend these:


Board dimensions

A20-OLinuXino-LIME2 basic dimensions in mils: 3305.5 x 2347.0

Some additional measures might be seen in the image of A10-OLinuXino-LIME which has almost identical layout. It is available as .png here: link

CAD files

A20-OLinuXino-LIME2 is an Open Source Hardware, CAD files are available at GitHub

The CAD product used to design OLinuXino is Eagle and you can download evaluation free version from their web.

Board Layout

A20-OLinuXino-LIME2 top naming extras.jpg


A20-OLinuXino-LIME2 bottom naming.jpg

Software

Linux Commands

Linux-Commands Brief Linux Command reference

Python library for GPIO, I2C and SPI control

The Debian Linux Python package for A20-OLinuXino-LIME2 is called pyA20Lime2. It makes the access to GPIO, I2C and SPI considerably easier. It is installed in the default Debian image. More information and examples on how it can be used might be found here:

Link to pyA20Lime2 package at python.org

GPIO under Linux

GPIOs are located in /sys/class/gpio directory. Note that first you have to export GPIOs. For example:

add gpioPH2

   root@A20:~# echo 20 > /sys/class/gpio/export

make PH2 output

   root@A20:~# echo out > //sys/class/gpio/gpio20_ph2/direction

turn on onboard LED(connected to PH2)

   root@A20:~# echo 1 > /sys/class/gpio/gpio20_ph2/value

turn off onboard LED(connected to PH2)

   root@A20:~# echo 0 > /sys/class/gpio/gpio20_ph2/value

Full list with supported GPIOs is:

   gpio21_ph7   gpio33_ph20  gpio45_pb12  gpio57_pi2   gpio69_pi14
   gpio10_pg11  gpio22_ph9   gpio34_ph21  gpio46_pb13  gpio58_pi3   gpio6_pg5
   gpio11_pc3   gpio23_ph10  gpio35_ph22  gpio47_pb14  gpio59_pi4   gpio70_pi15
   gpio12_pc18  gpio24_ph11  gpio36_ph23  gpio48_pb15  gpio5_pg4    gpio71_pi16
   gpio13_pc19  gpio25_ph12  gpio37_pb3   gpio49_pb16  gpio60_pi5   gpio72_pi17
   gpio14_pc20  gpio26_ph13  gpio38_pb4   gpio4_pg3    gpio61_pi6   gpio73_pi18
   gpio15_pc21  gpio27_ph14  gpio39_pb5   gpio50_pb17  gpio62_pi7   gpio74_pi19
   gpio16_pc22  gpio28_ph15  gpio3_pg2    gpio51_ph24  gpio63_pi8   gpio75_pi20
   gpio17_pc23  gpio29_ph16  gpio40_pb6   gpio52_ph25  gpio64_pi9   gpio7_pg6
   gpio18_pc24  gpio2_pg1    gpio41_pb7   gpio53_ph26  gpio65_pi10  gpio8_pg7
   gpio19_ph0   gpio30_ph17  gpio42_pb8   gpio54_ph27  gpio66_pi11  gpio9_pg8
   gpio1_pg0    gpio31_ph18  gpio43_pb10  gpio55_pi0   gpio67_pi12  gpiochip1
   gpio20_ph2   gpio32_ph19  gpio44_pb11  gpio56_pi1   gpio68_pi13 

Add Voice to your OLinuXino project

Installation of Festival on OLinuXino

How To?

How to generate boot-able SD-card Debian Linux image for A20-OLinuXino-LIME2?

Build instructions and required files for the latest Debian images: instructions and files at the GitHub page

Note that Linux-Sunxi Kernel is a work-in-progress, this means you can try the current stage/sunxi-x.x branch but if something is broken and doesn't work just revert to the git tags we give in the blog and they would work for sure.

Sunxi u-boot loader The linux-sunxi git page contains a lot of sources for all Olimex Allwinner boards.

How to connect a display and adjust the video output resolution?

There is a separate article on the subject: how to connect display to a Lime board

Is it possible to boot Debian from NAND? Do you provide such image?

Yes, it is possible. Use the latest Debian Jessie image and write "nandinstall". More information can be found in this wiki article: installing Debian Jessie to the 4GB NAND memory

There are other people who are also successful in booting Debian from the NAND. Make sure to check on the forum. Make sure to check the number of very good and optimized A20-OLinuXino Debian images by Igor Pečovnik. There are also his instructions for NAND installation of Debian: link to his web-site

How to detect and enable the Ethernet controller (if it is disabled by default)?

Note: in the previous Debian releases the Ethernet was auto-detected and initialized during boot BUT this was causing big delays in the start-up of the board if you didn't want to use Ethernet or if there wasn't Ethernet cable connected.

You can enable it by following these two steps:

1. To check under what name the LAN is associated write "ifconfig –a"

2. If, for example, it is under eth0 name, then write: "dhclient eth0"

This should enable the Ethernet and then SSH would also be available.

How to download new Android image to the NAND memory of my A20 board?

Follow these steps to download the image to the NAND memory:

  • 2. Go to firmware tab of the program and point to a valid Android image (the latest official one may also be downloaded above).
  • 3. Disconnect the power supply and USB cable from the A20 board.
  • 4. Press and hold RECOVERY button, apply power supply 5V, release RECOVERY button.
  • 5. Connect USB cable to the mini USB connector.
  • 6. You will be asked for drivers for the bootloader. Navigate to the folder where you extracted the PhoenixSuit and install the drivers from the respective executables (or manually point the installer to the drivers folder in the PhoenixSuit installation path).
  • 7. PhoenixSuit will detect the board and would ask for the method of writing the image. Choose method of writing the image and confirm your wish to write the image.
  • 8. Wait till upgrade succeeds


Note that it is not recommended to have your mini USB connected to an external USB hub. This might cause delays and might distort the signal levels. Always test with the USB connected straight to the USB ports of your computer.

How to generate Arch Linux image?

Recent forum post by user progmetalbg here: at Olimex forums

Older step by step instructions on how to build Arch Linux image for another A20 board

How do I write the official Android image to a micro SD card for my A20 board?

A: First download one of the official Android images, which might be found in the Android section above.

Make sure that the download link you visit clearly indicates that the image is suitable for the microSD card since there are images suitable for NAND memory also. The images suitable for the microSD memory and those suitable for NAND card are different. However, the upload method is almost identical – using PhoenixSuit.

There are two types of Android images for microSD card that we usually provide and each of them has to be downloaded to a microSD card using a different method. The image provided for microSD card is either the native Android image that can be downloaded to the card via a software tool like PhoenixSuit (through the board) or an image taken from an already prepared microSD card that requires to simply write the image (through a microSD card reader).

It is more likely that you have an Android image that requires a simple copy to a card. If that is the case you can follow the exact steps as for Linux (e.g. using "Win32 Disk Imager" or "dd" command).

In order to prepare a microSD card with a native Android you will need a software tool called PhoenixSuit and then:

• Install and run PhoenixSuit (can be found here: download from google drive)

• Go to the firmware tab of the program and point to a valid Android image (note that the images on Gdrive are compressed and you have to extract them to .img files to be able write them with PhoenixSuit)

• Disconnect the power supply and USB cable from the A20 board. Put an SD card in micro SD holder. We recommend either a 4GB or a 8GB class 10 card.

• Press and hold RECOVERY button, apply power supply 5V, release RECOVERY button.

• Connect USB cable to the mini USB connector.

• You will be asked for drivers for the boot-loader. Navigate to the folder where you extracted the PhoenixSuit and install the drivers from the respective executables (or manually point the installer to the drivers folder in the PhoenixSuit installation path).

• PhoenixSuit will detect the board and would ask for the method of writing the image. Choose method of writing the image and confirm your wish to write the image.

• Wait till upgrade succeeds

Note that it is not recommended to have your mini USB connected to an external USB hub. This might cause delays and might distort the signal levels. Always test with the USB connected straight to the USB ports of your computer.

Important: When Android runs for very first time it takes several minutes to initialize all files and buffers please do not cut the power supply during this process! Also when fresh image is installed fast boot may be disabled, which means that when you apply power supply after few seconds Android will go in sleep mode and you have to press POWER button to start it, you can change to fast boot when you power off there is dialog box asking you if you want next boot to be fast boot, you have to check this box before you power off. Also note that you must do touch screen calibration when you run Android for very first time which might require a mouse.

I don't have neither serial cable, nor HDMI monitor. I also can't access the local Ethernet network. Can I somehow access the board anyway?

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 – 192.168.2.1.

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 192.168.2.1.

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.

How to edit board configurations and definitions in the official Debian Linux?

Do you want a custom video resolution output? Do you need a different port definition? Do you need to change the hardware defitions of the board?

You would need to edit the board's script.bin/script.fex file. How to do it is described in another separate article: how to edit board configurations and definitions in the official Debian Linux.

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