OLIMEX A13-OLinuXino User manual

A13-OLinuXino and A13-OLinuXino-WIFI
Open-source single-board
Android 4.0 mini-computer
U ER’ MANUAL
Revision G, October 2014
Designed by OLIMEX Ltd, 2012
All boards produced by Olimex LTD are ROHS compliant

OLIMEX© 014 A13-OLinuXino user's manual
DI CLAIMER
© 01 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 infor ation in this docu ent is provided in connection with Oli ex products. No license, express
or i plied or otherwise, to any intellectual property right is granted by this docu ent or in connection
with the sale of Oli ex products.
The Hardware project is released under the Creative Commons Attribution-Share Alike 3.0 United States
License. You may reproduce it for both your own personal use, and for commercial use. You will have to
provide a link to the original creator of the project http://www.olimex.com on any documentation or website.
You may also modify the files, but you must then release them as well under the same terms. Credit can be
attributed through a link to the creator website: http://www.olimex.com
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 WARRANTY FOR THE DESIGN MATERIALS AND THE
COMPONENTS USED TO CREATE A13-OLINUXINO AND A13-OLINUXINO-
WIFI. THEY ARE CONSIDERED SUITABLE ONLY FOR A13-OLINUXINO AND
A13-OLINUXINO-WIFI.
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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 arket and purpose of the board ............................................................................... 6
1.3 Board variants .......................................................................................................................... 6
1.4 Organization ............................................................................................................................. 6
CHAPTER 2: ETTING UP THE OLINUXINO BOARD ..................................... 8
2. Introduction to the chapter ....................................................................................................... 8
2.1 Electrostatic warning ............................................................................................................... 8
2.2 Require ents ........................................................................................................................... 8
2.3 Powering the board .................................................................................................................. 9
2.4 Prebuilt software .................................................................................................................... 10
2.5 Button functions in Android .................................................................................................. 11
2.6 How we configured the Android i age ................................................................................ 11
2.6.1. Getting the Android DK tools ................................................................................................................... 11
2.6.2. Adding information for the board in the Linux ........................................................................................ 11
2.6.3. Installing the DK tools .............................................................................................................................. 12
2.6.4. Connecting the A13-OLinuXino ................................................................................................................ 13
2.6.5. Downloading the default config file and script tool .................................................................................. 14
2.6.6. Applying the script and uploading the confing ......................................................................................... 14
2.6.7. Restarting the A13-OLinuXino .................................................................................................................. 14
2.7 GPIO under Debian ............................................................................................................... 14
2.8 I2C and SPI under Debian .................................................................................................... 16
2.9 Software support .................................................................................................................... 16
CHAPTER 3: A13-OLINUXINO BOARD DE CRIPTION ................................. 17
3. Introduction to the chapter ..................................................................................................... 17
3.1 Layout (top view) ................................................................................................................... 17
CHAPTER 4: THE ALLWINNER A13 MICROCONTROLLER ....................... 18
4. Introduction to the chapter ..................................................................................................... 18
4.1 The icrocontroller ............................................................................................................... 18
4.2 Block diagra ........................................................................................................................ 20
CHAPTER 5: CONTROL CIRCUITY ................................................................... 21
5. Introduction to the chapter ..................................................................................................... 21
5.1 Reset ........................................................................................................................................ 21
5.2 Clocks ...................................................................................................................................... 21
5.3 Power supply circuit .............................................................................................................. 21
CHAPTER 6: CONNECTOR AND PINOUT ...................................................... 22
6. Introduction to the chapter ..................................................................................................... 22
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6.1 Co unication with the A13 ............................................................................................... 22
6.1.1 U B communication ..................................................................................................................................... 22
6.1.2 UART1 interface ........................................................................................................................................... 23
6.2 SD/MMC slot .......................................................................................................................... 24
6.3 UEXT odule ......................................................................................................................... 25
6.4 GPIO-1 (General Purpose Input/Output) 10pin connector ............................................... 26
6.5 GPIO-2 (General Purpose Input/Output) 40pin connector ............................................... 27
6.6 LCD_CON 40pin connector .................................................................................................. 28
6.7 PWR Jack ............................................................................................................................... 29
6.8 Headphones and icrophone connector .............................................................................. 29
6.9 Battery connector ................................................................................................................... 30
6.7 VGA video connector ............................................................................................................. 30
6.8 Ju per description ................................................................................................................ 31
6.8.1 CE_NAND_E ................................................................................................................................................ 31
6.8.2 3.3V_OPTION, 1.5V_E ................................................................................................................................ 31
6.8.3 5V_E .............................................................................................................................................................. 31
6.8.4 HO T_EN, 5V_E_WIFI, WIFI-3.3V/5V_U B .......................................................................................... 31
6.9 Additional hardware co ponents ........................................................................................ 31
CHAPTER 7: CHEMATIC .................................................................................. 33
7. Introduction to the chapter ..................................................................................................... 33
7.1 Eagle sche atic ...................................................................................................................... 33
7.2 Physical di ensions ............................................................................................................... 34
CHAPTER 8: REVI ION HI TORY AND UPPORT ........................................ 35
8. Introduction to the chapter ..................................................................................................... 35
8.1 Docu ent revision ................................................................................................................. 35
8.2 Board revision ........................................................................................................................ 36
8.3 Useful web links and purchase codes ................................................................................... 37
8.4 Product support ..................................................................................................................... 38
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OLIMEX© 014 A13-OLinuXino user's manual
CHAPTER 1: OVERVIEW
1. Introduction to the chapter
Thank you for choosing the OLinuXino single board computer from Olimex! This document
provides a user’s guide for the Olimex 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 OLinuXino development board enables code development of applications running on the
microcontroller A13, 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
•A13 Cortex A8 processor at 1GHz, 3D Mali400 GPU
•51 MB RAM
•6-16VDC input power supply, noise immune design
•3 + 1 USB Host, 3 available for users 1 for (optional) WIFI RTL8188CU 80 .11n 150Mbit
module on board
•1 USB OTG which can power the board
•SD-card connector for booting the Linux image
•(optional) 4GB NAND flash
•VGA video output – 800×600 resolution
•LCD signals available on connector so you still can use LCD if you diasble VGA/HDMI
•Audio Output
•Microphone input
•RTC PCF8536 on board for real time clock and alarms
•5 Keys on board for android navigation
•UEXT connector for connecting addtional UEXT modules like Zigbee, Bluetooth, Relays,
etc
•GPIO connector with 68/74 pins and these signals : 17 for adding NAND flash; for
connecting LCDs; 0+4 including 8 GPIOs which can be input, output, interrupt sources; 3x
I C; x UARTs; SDIO for connectinf SDcards and modules; 5 system pins: +5V, +3.3V,
GND, RESET, NMI
•(Optional low cost 7" LCD with touchscreen)
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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. They are suitable for
embedded programming enthusiasts, Linux and Android gadget fans 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 mobility of the board and the low ratio
price to productivity.
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.
1.3 Board variants
There are three major processor variants. According to the names: A13-OLinuXino and A13-
OLinuXino-MICRO and A13-SOM.
The base model has also two flavors: A13-OLinuXino and A13-OLinuXino-WIFI. The first one is
the base model that goes without any operating system image on board, while the second has two
additional components – a WIFI module on the board and NAND memory with stored Android
image.
The A13-OLinuXino-Micro differs from the base A13-OLinuXino by having only 1 USB host, 1
USB OTG, no power connector, no NAND memory, no WIFI, no audio out connector, less buttons.
If you are looking for an A13 board with tiny dimensions and suitable for implementing in own
designs then refer to A13-SOM board – it has tiny dimensions.
There are more powerful A10 and A 0 designs that Olimex manufactures nowadays. Boards like
A 0-OLinuXino-LIME; A 0-OLinuXino-MICRO and A 0-OLinuXino-LIME are generally faster
and capable of better video output.
1.4 Organization
Each section in this document covers a separate topic, organized as follow:
–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 A13 – Allwinner
processor
–Chapter 5 is an explanation of the control circuitry associated with the microcontroller to
reset. Also shows the clocks on the board
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–Chapter 6 covers the connector pinout, peripherals and jumper description
–Chapter 7 provides the schematics
–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 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.
2.2 Requirements
In order to set up the OLinuXino optimally, the following items are required:
- 6V to 16V, 6W required (6V @ 1A or 16V @ 0.4A) – for optimal power
- LCD (preferably with touchscreen panel) display for the LCD_CON OR TV monitor with RGB
port
- A USB mouse – if you use touchscreen LCD you might skip the mouse
Additional items include:
- USB keyboard – for convenience with text input
- USB-SERIAL-CABLE-F – for serial communication with UART1 connector
- USB-MINI-CABLE – for connecting with the USB OTG and being able to firmware update ot
power A13-OLinuXino
- Wireless internet connectivity or USB modem – for browser access and access to the Android
market
Some of the suggested items can be purchased by Olimex, for instance:
SY0612E – power supply adapter 1 V/0.5A for A13-OLinuXino
USB-SERIAL-CABLE-F – USB serial console cable female
USB-MINI-CABLE – standard USB type A to USB type mini cable
A 7'' LCD display with optional touch screen panel is available for purchase also:
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https://www.olimex.com/Products/OLinuXino/A13/A13-LCD7/
https://www.olimex.com/Products/OLinuXino/A13/A13-LCD7-TS/
Note that if you wish to use one of the LCD displays mentioned above you need to upload different
Android image – configured for 480×800 screen resolution.
2.3 Powering the board
There are three possible ways of powering A13-OLinuXino – via external supply using the power
jack, via a battery using the battery connector or via the USB OTG connector. Depending on your
preferred way of powering A13-OLinuXino you might need additional hardware.
The preferred way of powering board is via the PWR jack with 6Vdc to 16Vdc with a power of 6W
(e.g. 6Vx1A to 16Vx0.4A). This will make the board fully powered and able to power all the
peripherals connected to it.
When powered by the typical 3.7V Lithium-polymer battery the board will be fully functional and
you will be able to operate with most of the peripherals. However when using all three USB-A
connectors and an LCD connected to the LCD_con it might cause flickering and not sufficient
power. If you suspect the power is not enough for the peripherals you have connected use the PWR
jack.
The board can be also powered by the USB OTG connector (mini USB standard) but the voltage
provided is not enough to power a possible LCD connected to the LCD_con. However, this power
option is capable of driving the board when using external display connected to the VGA connector.
If you have a standard LCD display connected to LCD_con, Android and WIFI running the typical
consumption is between 150mA and 350mA depending on the current load. While the board is in
stand-by mode it consumes a minimum of 60mA. All the three approximate values above were
taken when I applied 1 V to the board.
Important! Avoid disconnecting the power supply while Android or Linux is running, since that
might corrupt the operating system and you will need to install the OS again (for Android install
instructions check chapter .6. Use the PWR_BUT before disconnecting the supply.
If the board has entered power-down state you can bring it back without restart using the
PWR_BUT.
For the European customers we sell a power supply adapter 1 V/0.5A – SY0612E. We also sell
USB OTG to USB type A cables if you lack such.
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2.4 Prebuilt software
The A13-OLinuXino-WIFI board comes with Android 4.0 ready to use. The default settings of the
software are followed.
Note that the A13-OLinuXino (standard version without WIFI) lacks NAND memory and there isn't
OS uploaded on the shipped boards (no Android).
How we have installed the software? We have configured an Android image with settings suitable
for A13-OLinuXino. Then using LiveSuit tools we uploaded the image to the board. To activate
A13 bootloader do as follows: run Livesuit, disconnect the power supply and USB cable, then press
HOME button, apply power supply, attach USB cable and release the button, Livesuit will detect
the bootloader and will ask which file to program to the NAND flash. The image will be available
for users to try and tweak the settings. You can find and image with the view of the progress
window in LiveSuit:
Download links to all available images (and tools needed) can be found at the A13-OLinuXino wiki
page: https://www.olimex.com/wiki/A13-OLinuXino.
Helpful information about the Android and Linux images can be found at the OLIMEX forums.
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2.5 Button functions in Android
The following buttons represent functions in the Android:
PWR_BUT – used to wake the board from stand-by
HOME – shows the home screen; note that HOME is also used to enter bootloader mode for
firmware update
ENTER – to select a choice
MENU – brings up the main menu
VOL+ – increases the volume
VOL- – lowers the volume
For more information on the button functions check the Android documentation.
Note that RESET button will perform a hardware reset of the board, not controlled by the OS.
2.6 How we configured the Android image
This is a detailed explanation of how we got to tweak the Android image configuration files. It is
worth mentioning that we used Ubuntu with Linux Kernel 3. for the steps below.
2.6.1. Getting the Android DK tools
Download the Android SDK tools for Linux from: http://developer.android.com/sdk/index.html
Note that you have to click “Other platforms” and get the one for Linux. Then you extract it:
tar zxfv android-sdk_r 0.0.3-linux.tgz
Note that the above line would vary depending on the version you have downloaded (by the time of
writing 0.0.3 was the latest one).
2.6.2. Adding information for the board in the Linux
Create the following file:
.../etc/udev/rules.d/70-android.rules
and add the following line inside:
SUBSYSTEM=="usb_device", SYSFS{idVendor}=="18d1", MODE="0666"
then we save the file and change its properties with chmod +x 70-android.rules and reboot the
computer.
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2.6.3. Installing the DK tools
Navigate to the folder where we extracted the tools (folder tools) in point 1 and start it:
./android
From the check boxes select to install Android SDK Tools, Android SDK Platform Tools and
Android 4.0 API
2.6.4. Connecting the A13-OLinuXino
Power the A13-OLINUXINO. Now connect the miniUSB to the board and wait a bit for the USB to
enumerate.
After the tools are installed we navigate to “platform-tools” folder located in the directory of the
tools (where we extracted in point 1), then we enter:
./adb devices
which will show us the list of the available devices. The output should would like:
List of devices attached
20080411 device
However if we get “bash: ./adb: No such file or directory“- we have to check if the ia3 -libs are
installed if not, we install them with:
apt-get install ia3 -libs
If again the device is not listed we try to stop and run the server again with the following (we have
to be logged as root!):
cd /home/android-sdk/platform-tools/
./adb kill-server
./adb start-server
Exit the root and enter the shell of the device
./adb shell
We then create mounting point for the NAND memory :
mkdir /sdcard/nanda
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and finally we mount the NAND:
mount -t vfat /dev/block/nanda /sdcard/nanda
Note : NAND mounting should be performed every time the device is restarted!
2.6.5. Downloading the default config file and script tool
Get the default 800×600 config file from:
https://docs.google.com/open?id=0B7WHuNCASY8caVRlV 9GdUVPX3M
Open a new console (which will be used to edit the config file) - - then we download the following
script:
https://docs.google.com/file/d/0B_DiNI-XElr-
MjQ4MmJhZGEtNmU1NS00MzllLWIzOWMtMzExODc5NTRkMGQ3/edit
We save both of the above files (both should be in the same folder)
Then we execute from the console:
chmod +x script
2.6.6. Applying the script and uploading the confing
After we have edited the file as we win we do:
./script A13_config_600x800.fex_ok
and then we push it on the device
path_to_android_sdk/android-sdk-linux/platform-tools/adb push A13_config_600x800.fexbin
/sdcard/nanda/script.bin
2.6.7. Restarting the A13-OLinuXino
We go to the shell of the A13-OLinuXino board and
reboot
2.7 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)
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.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
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
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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.
Instructions on how to edit board configurations might be found here:
https://www.olimex.com/wiki/How_to_edit_board_configurations_and_definitions_in_the_official_
Debian_Linux
Information on how to use the WIFI, Ethernet or GPIOs is available at the following web address:
https://www.olimex.com/wiki/Configuration_of_hardware_in_the_debian_image
2.8 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 pyA13 might be found here:
https://pypi.python.org/pypi/pyA13
At the same web address you would also find a set of examples on how module is used.
2.9 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/A13-OLinuXino.
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/
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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OLIMEX© 014 A13-OLinuXino user's manual
CHAPTER 3: A13-OLINUXINO 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 A13-OLinuXino
board itself.
3.1 Layout (top view)
The picture above shows the initial revision of A13-OLinuXino. Note that the version of the board
pictured does not have additional NAND memory nor WIFI module.
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CHAPTER 4: THE ALLWINNER A13 MICROCONTROLLER
4. Introduction to the chapter
In this chapter is located the information about the heart of OLinuXino – its microcontroller. The
information is a modified version of the datasheet provided by its manufacturers.
4.1 The microcontroller
CPU/GPU
ARM Cortex-A8 Core
3 KB D-Cache/ 3 KB I-Cache
56KB L Cache
Mali-400 3-D Engine
VPU
HD Video Decoding
19 0*1080@30fps
Support H. 64, H. 63, VC1, Mpeg1/ /4
Divx 3/4/5/6, Xvid, VP6/8, AVS etc
HD Video Encoding
Support encoding in H. 64 format
Up to 19 0*1080 at 30fps
DPU
LCD Interfaces: CPU, RGB
Memory
DDR /DDR3: Up to 533MHz
16 bits Data Bus
Memory capacity up to 51 MB
MLC/TLC/SLC/EF-NAND
 flash chips, ECC 64-bit
Support NAND of 5xnm, 4xnm, 3xnm, xnm
Support NADN of Samsung, Toshiba, Hynix
Peripherals
USB .0 OTG, USB .0 HOST
(OHCI/EHCI）
SD Card V.3.0, eMMC V.4.
SPI, TWI and UART
integrated Audio Codec
CSI
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R-TP Controller
4-wire resistive TP interface
 points and gesture detection
Boot Devices
NAND Flash
SPI Nor Flash
SD Card
USB
Powerful Acceleration
Graphic (3D, Mali400 MP)
VPU (1080P）
APU
E-Reader
Ultra-low System Power Consumption
15~ 0% lower than competitors
Smart Backlight: auto adjust backlight
acc. to the image display
Package
eLQFP176
More information can be found on Allwinner's web site at the following web-address:
http://www.allwinnertech.com/product/A13.html
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4.2 Block diagram
The block diagram is taken from Allwinner's datasheet.
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CHAPTER 5: CONTROL CIRCUITY
5. Introduction to the chapter
Here you can find information about reset circuit and quartz crystals locations, the power supply
circuit is discussed.
5.1 Reset
The reset line is handled by the AXP 09 (which is an enhanced single cell Li-battery and power
system management IC that goes together with the Allwinner processor) and goes to processor pin
159 via R4(47k). The reset circuit is connected to button RESET, which means pressing RESET
would perform a hardware reset on the board.
5.2 Clocks
4 MHz quartz crystal Q1 is connected to pins 91 and 9 of the A13 processor.
1 MHz quartz crystal Q is found at pins 6 and 7 of the GL850G (the USB controller).
3 768 kHz (RTC clock) quartz crystal Q3 is found connected to pins 1 and of the
RTC_MODULE (PCF8563T)
5.3 Power supply circuit
The power supply is handled mainly by AXP 09 power management system, an Allwinner chip that
goes together with the A13 processor. The power supply circuit of A13-OLinuXino allows flexible
input supply from 6V to 16V. The minimum amperage suggested is 1A, and this threshold would
rise if using all the three USB-HOSTs, a lot of GPIOs and LCD_con.
The board can also be powered by 3.7V Li-Po battery retaining its functionality or by USB (limiting
the use of peripherals.
Important! Avoid disconnecting the power supply while Android or Linux is running, since that
might corrupt the NAN memory (and the operating system files) and you will need to install the OS
again (for Android install instructions check chapter .6. Hold the PWR_BUT and then navigate to
shut down before disconnecting the supply.
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