Difference between revisions of "NanoPi Fire2A"

Latest revision as of 08:15, 3 July 2024

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1 Introduction

Overview

Front

Back

• The NanoPi Fire 2A is a super tiny Quad-Core Cortex-A9 ARM board. It uses Samsung's S5P4418 SoC and has onboard 512M DDR3 RAM. The Fire2A has a Gbps Ethernet, MicroHDMI port, CMOS camera interface and RGB LCD interface. Its GPIOs are compatible with RPi's GPIO. Its size is only 75 x 40 mm.
• The NanoPi Fire 2A has an MCU based power management system and supports dynamic voltage control with good performance and reliability. FriendlyElec provides image files of FriendlyCore (based on UbuntuCore 16.04) and Debian for NanoPi Fire2A. The FriendlyCore image has Qt-5.9 and OpenGL ES1.1/2.0, and supports video playing with hardware-decoding/encoding. It is a good choice for rapidly developing products for applications in distributed computing, artificial intelligence and embedded systems.

2 Hardware Spec

• CPU: S5P4418, 400MHz~1.4GHz, DVFS, dynamic voltage control, scaling up to 1.4G Hz
• RAM: 512MB DDR3
• Connectivity: Gbps Ethernet port
• PMU Power Management: Implemented by a Cortex-M0 MCU, support software power-off, and RTC alarm power-on functions
• USB 2.0 Type A x 1
• Debug Serial Port/UART0 x 1
• microSD Slot x 1
• microUSB x 1: for data transmission and power input
• LCD Interface: 0.5 mm pitch SMT FPC seat, for full-color LCD (RGB: 8-8-8)
• HDMI: HDMI 1.4A, microHDMI(Type-D), 1080P60
• DVP Camera Interface: 0.5mm spacing FPC socket. It includes ITU-R BT 601/656 8-bit, I2C, PWM and IO
• GPIO: 2.54mm spacing 40pin, compatible with Raspberry Pi's GPIO. It includes UART, SPI, I2C, PWM, IO etc
• Button: Power Button x 1, Reset Button x 1
• LED: LED for Power Indication x 1, System LED x 1
• RTC: RTC Battery Seat
• PCB Dimension: 75 x 40mm
• Power: DC 5V/2A
• Temperature measuring range: -20℃ to 80℃
• OS: FriendlyCore(based on Ubuntu16.04 with Linux Kernel 4.4, Qt 5.10.0 and OpenGL2.0) and Debian

3 Software Features

3.1 FriendlyCore (Based on UbuntuCore16.04 with Qt 5.10.0 and OpenGL ES1.1/2.0)

• Linux Kernel 4.4
• npi-config: npi-config: system configuration utility for setting passwords, language, timezone, hostname, SSH and auto-login
• networkmanager: manage network
• system log output from serial port
• welcome window with basic system information and status
• auto-login with user account "pi" with access to npi-config
• LibMali & OpenGL2.0 driver supported
• Qt 5.10.0 TLS with OpenGL hardware acceleration
• HD video playing with hardware decoding
• GStreamer 1.0 with VPU hardware acceleration
• RPI.GPIO Support: work in progress, not ready yet
• WiringPi Support: work in progress, not ready yet

4 Diagram, Layout and Dimension

4.1 Layout

NanoPi Fire2A Layout

• GPIO Pin Spec

Pin#	Name	Pin#	Name
1	SYS_3.3V	2	VDD_5V
3	I2C0_SDA	4	VDD_5V
5	I2C0_SCL	6	DGND
7	GPIOD8/PPM	8	UART3_TXD/GPIOD21
9	DGND	10	UART3_RXD/GPIOD17
11	UART4_TX/GPIOB29	12	GPIOD1/PWM0
13	GPIOB30	14	DGND
15	GPIOB31	16	GPIOC14/PWM2
17	SYS_3.3V	18	GPIOB27
19	SPI0_MOSI/GPIOC31	20	DGND
21	SPI0_MISO/GPIOD0	22	UART4_RX/GPIOB28
23	SPI0_CLK/GPIOC29	24	SPI0_CS/GPIOC30
25	DGND	26	GPIOB26
27	I2C1_SDA	28	I2C1_SCL
29	GPIOC8	30	DGND
31	GPIOC7	32	GPIOC28
33	GPIOC13/PWM1	34	DGND
35	SPI2_MISO/GPIOC11	36	SPI2_CS/GPIOC10
37	AliveGPIO3	38	SPI2_MOSI/GPIOC12
39	DGND	40	SPI2_CLK/GPIOC9

• Debug Port（UART0）

Pin#	Name
1	DGND
2	VDD_5V
3	UART_TXD0
4	UART_RXD0

• DVP Camera Interface Pin Spec

Pin#	Name
1, 2	SYS_3.3V
7,9,13,15,24	DGND
3	I2C0_SCL
4	I2C0_SDA
5	GPIOB14
6	GPIOB16
8	GPIOC13/PWM1
10	NC
11	VSYNC
12	HREF
14	PCLK
16-23	Data bit7-0

• RGB LCD Interface Pin Spec

Pin#	Name	Description
1, 2	VDD_5V	5V output, LCD power
11，20，29, 37，38，39，40, 45	DGND	ground
3-10	Blue LSB to MSB	RGB Blue
12-19	Green LSB to MSB	RGB Green
21-28	Red LSB to MSB	RGB Red
30	GPIOB25	available for users
31	GPIOC15	occupied by FriendlyElec one wire technology to recognize LCD models and control backlight and implement resistive touch, not applicable for users
32	XnRSTOUT Form CPU	low when system is reset
33	VDEN	signal the external LCD that data is valid on the data bus
34	VSYNC	vertical synchronization
35	HSYNC	horizontal synchronization
36	LCDCLK	LCD clock, Pixel frequency
41	I2C2_SCL	I2C2 clock signal, for capacitive touch's data transmission
42	I2C2_SDA	I2C2 data signal, for capacitive touch's data transmission
43	GPIOC16	interrupt pin for capacitive touch, used with I2C2
44	NC	not connected

• RTC

3.35uA@3V

• USB 2.0 Host

with 1A over current protection

Note

1. SYS_3.3V: 3.3V power output
2. VDD_5V: 5V power input/output. When the external device’s power is greater than the MicroUSB’s the external device is charging the board otherwise the board powers the external device. The input range is 4.7V ~ 5.5V
3. For more details please refer to the schematic. NanoPi Fire2A 1709 Schematic.pdf

4.2 Board Dimension

For more details please refer to the dxf drawimg document.NanoPi Fire2A 1709 dxf文件

5 Get Started

5.1 Essentials You Need

Before play with your NanoPi Fire2A please get the following items ready

• NanoPi Fire2A
• microSD Card/TFCard: Class 10 or Above, minimum 8GB SDHC
• microUSB power. A 5V/2A power is a must
• HDMI monitor or LCD
• USB keyboard and mouse
• A Host running Ubuntu 18.04 64 bit system

5.2 Boot from SD Card

Get the following files from here download link:

• Get a 8G SDHC card and backup its data if necessary.
  

• Uncompress these files. Insert an SD card(at least 4G) into a Windows PC and run the win32diskimager utility as administrator. On the utility's main window select your SD card's drive, the wanted image file and click on "write" to start flashing the SD card.
  
• Insert this card into your board's boot slot, press and hold the boot key (only applies to a board with onboard eMMC) and power on (with a 5V/2A power source). If the PWR LED is on and LED1 is blinking this indicates your board has successfully booted.
  

5.3 Flash image to eMMC with eflasher

• Download eflasher image file
  

An image file's name is as : s5p4418-eflasher-OSNAME-YYYYMMDD.img.zip
The "OSNAME" is the name of an OS e.g. android, friendlycore and etc;
This image file is used for making an installation SD card and it contains a Ubuntu core system and a utility EFlasher;
Download s5p4418-eflasher-OSNAME-YYYYMMDD.img.zip to a host PC and get a windows utility win32diskimager.rar as well;

• Make Installation SD Card with eflasher
  

Extract the package with a 7z utility and you will get a file with an extension ".img". Insert an SDHC card(minimum 8G or above) to a PC running Windows, run the Win32DiskImager utility as administrator, click on "Image File" to select your wanted file, select your SD card and click on "Write" to start flashing the Image to your SD card;
If your PC runs Linux you can command "dd" to extract the package and get an ".img" file and write it to your SD card;

• Operate in GUI Window: Flash OS to eMMC

Insert your SD card to NanoPi-Fire2A, connect an HDMI monitor or LCD to your board, press and hold the "boot" key beside the Ethernet port, power on the board you will see a pop-up window asking you to select an OS for installation. Select your wanted OS and start installation.

• Operate in Commandline Utility: Flash OS to eMMC

Insert an installation SD card to NanoPi-Fire2A, log into or SSH to your board and run the following command to start EFlasher:

sudo eflasher

5.3.1 Make Installation Card under Linux Desktop

• 1) Insert your SD card into a host computer running Ubuntu and check your SD card's device name

dmesg | tail

Search the messages output by "dmesg" for similar words like "sdc: sdc1 sdc2". If you can find them it means your SD card has been recognized as "/dev/sdc". Or you can check that by commanding "cat /proc/partitions"

• 2) Downlaod Linux script

• 3) Here is how to make a Lubuntu desktop SD card

sudo ./fusing.sh /dev/sdx lubuntu

(Note: you need to replace "/dev/sdx" with the device name in your system)
When you run the script for the first time it will prompt you to download an image you have to hit “Y” within 10 seconds otherwise you will miss the download

• 4) Run this command to make a complete image file:

sudo ./mkimage.sh lubuntu

More content please refre: Assembling the SD card image yourself

5.4 Extend SD Card Section

• When Debian/Ubuntu is loaded the SD card's section will be automatically extended.
• When Android is loaded you need to run the following commands on your host PC to extend your SD card's section:

sudo umount /dev/sdx?
sudo parted /dev/sdx unit % resizepart 4 100 resizepart 7 100 unit MB print
sudo resize2fs -f /dev/sdx7

(Note: you need to replace "/dev/sdx" with the device name in your system)

5.5 LCD/HDMI Resolution

When the system boots our uboot will check whether it is connected to an LCD or to an HDMI monitor. If it recognizes an LCD it will configure its resolution. Our uboot defaults to the HDMI 720P configuration.
If you want to modify the LCD resolution you can modify file "arch/arm/plat-s5p4418/nanopi2/lcds.c" in the kernel and recompile it.
If your NanoPi-Fire2A is connected to an HDMI monitor and it runs Android it will automatically set the resolution to an appropriate HDMI mode by checking the "EDID". If your NanoPi-Fire2A is connected to an HDMI monitor and it runs Debian by default it will set the resolution to the HDMI 720P configuration. If you want to modify the HDMI resolution to 1080P modify your kernel's configuration as explained above.

5.6 Update SD Card's boot parameters From PC Host

Insert your SD card into a host PC running Linux, if you want to change your kernel command line parameters you can do it via the fw_setevn utility.
Check the current Command Line:

For example, to disable android SELinux, You can change it this way:

./fw_setenv /dev/sdc bootargs XXX androidboot.selinux=permissive

The "XXX" stands for the original bootargs' value.

5.7 Run Android or Linux (TODO)

• 将制作好SD卡插入NanoPi-Fire2A，连接HDMI，按住靠近网口的boot按键，最后接电源(5V 2A)拨动开关，NanoPi-Fire2A会从SD卡启动。你可以看到板上PWR灯常亮,LED1灯闪烁，这说明系统已经开始启动了，同时电视上也将能看到系统启动的画面。
  
• 要在电视上进行操作，你需要连接USB鼠标和键盘；如果你选购了LCD配件，则可以直接使用LCD上面的触摸屏进行操作。
  

6 Work with FriendlyCore

6.1 Introduction

FriendlyCore is a light Linux system without X-windows, based on ubuntu core, It uses the Qt-Embedded's GUI and is popular in industrial and enterprise applications.

Besides the regular Ubuntu core's features our FriendlyCore has the following additional features:

• it supports our LCDs with both capacitive touch and resistive touch(S700, X710, HD702, S430, HD101 and S70)
• it supports WiFi
• it supports Ethernet
• it supports Bluetooth and has been installed with bluez utilities
• it supports audio playing
• it supports Qt 5.10.0 EGLES and OpenGL ES1.1/2.0 (Only for S5P4418/S5P6818)

6.2 System Login

• If your board is connected to an HDMI monitor you need to use a USB mouse and keyboard.
• If you want to do kernel development you need to use a serial communication board, ie a PSU-ONECOM board, which will

For example, NanoPi-M1：

You can use a USB to Serial conversion board too.
Make sure you use a 5V/2A power to power your board from its MicroUSB port:
For example, NanoPi-NEO2：

• FriendlyCore User Accounts:

Non-root User:

   User Name: pi
   Password: pi

Root:

   User Name: root
   Password: fa

The system is automatically logged in as "pi". You can do "sudo npi-config" to disable auto login.

• Update packages

$ sudo apt-get update

6.3 Configure System with npi-config

The npi-config is a commandline utility which can be used to initialize system configurations such as user password, system language, time zone, Hostname, SSH switch , Auto login and etc. Type the following command to run this utility.

$ sudo npi-config

Here is how npi-config's GUI looks like:

6.4 Develop Qt Application

Please refer to: How to Build and Install Qt Application for FriendlyELEC Boards

6.5 Setup Program to AutoRun

You can setup a program to autorun on system boot with npi-config:

sudo npi-config

Go to Boot Options -> Autologin -> Qt/Embedded, select Enable and reboot.

6.6 Extend TF Card's Section

When FriendlyCore is loaded the TF card's section will be automatically extended.You can check the section's size by running the following command:

$ df -h

6.7 Transfer files using Bluetooth

Take the example of transferring files to the mobile phone. First, set your mobile phone Bluetooth to detectable status, then execute the following command to start Bluetooth search.：

hcitool scan

Search results look like：

Scanning ...
    2C:8A:72:1D:46:02   HTC6525LVW

This means that a mobile phone named HTC6525LVW is searched. We write down the MAC address in front of the phone name, and then use the sdptool command to view the Bluetooth service supported by the phone：

sdptool browser 2C:8A:72:1D:46:02

Note: Please replace the MAC address in the above command with the actual Bluetooth MAC address of the mobile phone.
This command will detail the protocols supported by Bluetooth for mobile phones. What we need to care about is a file transfer service called OBEX Object Push. Take the HTC6525LVW mobile phone as an example. The results are as follows：

Service Name: OBEX Object Push
Service RecHandle: 0x1000b
Service Class ID List:
  "OBEX Object Push" (0x1105)
Protocol Descriptor List:
  "L2CAP" (0x0100)
  "RFCOMM" (0x0003)
    Channel: 12
  "OBEX" (0x0008)
Profile Descriptor List:
  "OBEX Object Push" (0x1105)
    Version: 0x0100

As can be seen from the above information, the channel used by the OBEX Object Push service of this mobile phone is 12, we need to pass it to the obexftp command, and finally the command to initiate the file transfer request is as follows：

obexftp --nopath --noconn --uuid none --bluetooth -b 2C:8A:72:1D:46:02 -B 12 -put example.jpg

Note: Please replace the MAC address, channel and file name in the above command with the actual one.

After executing the above commands, please pay attention to the screen of the mobile phone. The mobile phone will pop up a prompt for pairing and receiving files. After confirming, the file transfer will start.

Bluetooth FAQ：
1) Bluetooth device not found on the development board, try to open Bluetooth with the following command：

rfkill unblock 0

2) Prompt can not find the relevant command, you can try to install related software with the following command：

apt-get install bluetooth bluez obexftp openobex-apps python-gobject ussp-push

6.8 WiFi

For either an SD WiFi or a USB WiFi you can connect it to your board in the same way. The APXX series WiFi chips are SD WiFi chips. By default FriendlyElec's system supports most popular USB WiFi modules. Here is a list of the USB WiFi modules we tested:

Index	Model
1	RTL8188CUS/8188EU 802.11n WLAN Adapter
2	RT2070 Wireless Adapter
3	RT2870/RT3070 Wireless Adapter
4	RTL8192CU Wireless Adapter
5	mi WiFi mt7601
6	5G USB WiFi RTL8821CU
7	5G USB WiFi RTL8812AU

You can use the NetworkManager utility to manage network. You can run "nmcli" in the commandline utility to start it. Here are the commands to start a WiFi connection:

• Change to root

$ su root

• Check device list

$ nmcli dev

Note: if the status of a device is "unmanaged" it means that device cannot be accessed by NetworkManager. To make it accessed you need to clear the settings under "/etc/network/interfaces" and reboot your system.

• Start WiFi

$ nmcli r wifi on

• Scan Surrounding WiFi Sources

$ nmcli dev wifi

• Connect to a WiFi Source

$ nmcli dev wifi connect "SSID" password "PASSWORD" ifname wlan0

The "SSID" and "PASSWORD" need to be replaced with your actual SSID and password.If you have multiple WiFi devices you need to specify the one you want to connect to a WiFi source with iface
If a connection succeeds it will be automatically setup on next system reboot.

For more details about NetworkManager refer to this link: Use NetworkManager to configure network settings

If your USB WiFi module doesn't work most likely your system doesn't have its driver. For a Debian system you can get a driver from Debian-WiFi and install it on your system. For a Ubuntu system you can install a driver by running the following commands:

$ apt-get install linux-firmware

In general all WiFi drivers are located at the "/lib/firmware" directory.

6.9 Ethernet Connection

If a board is connected to a network via Ethernet before it is powered on it will automatically obtain an IP with DHCP activated after it is powered up. If you want to set up a static IP refer to: Use NetworkManager to configure network settings。

6.10 Custom welcome message

The welcome message is printed from the script in this directory：

/etc/update-motd.d/

For example, to change the FriendlyELEC LOGO, you can change the file /etc/update-motd.d/10-header. For example, to change the LOGO to HELLO, you can change the following line：

TERM=linux toilet -f standard -F metal $BOARD_VENDOR

To:

TERM=linux toilet -f standard -F metal HELLO

6.11 Modify timezone

For exampe, change to Shanghai timezone:

sudo rm /etc/localtime
sudo ln -ls /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

6.12 Select the system default audio device

You can set the system default audio device by following the steps below.
Use the following command to view all the sound card devices in the system (Note: different development boards will have different results):

pi@NanoPi:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: nanopi2audio [nanopi2-audio], device 0: c0055000.i2s-ES8316 HiFi ES8316 HiFi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: nanopi2audio [nanopi2-audio], device 1: c0059000.spdiftx-dit-hifi dit-hifi-1 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0

As you can see, the following sound card devices are available on the hardware:

Sound card device	Sound card number	Description
nanopi2audio	device 0	3.5mm jack interface
nanopi2audio	device 1	HDMI

To configure the audio output to the 3.5mm jack, create or modify the configuration file /etc/asound.conf and modify it to the following:

pcm.!default {
    type hw
    card 0
    device 0
}
 
ctl.!default {
    type hw
    card 0
}

To configure to output audio to HDMI, change the device 0 above to device 1.

6.13 Run the X11 application

FriendlyCore system built-in lightweight Xorg，although there is no window manager, you can still run a single X-Windows application，For example, the program to run is ~/YourX11App，use the following command：

. /usr/bin/setqt5env-xcb
startx ~/YourX11App -geometry 1280x800

Note that there is a space between "." and /usr/bin/setqt5env-xcb. In addition, the resolution after -geometry should be changed to the actual resolution of your screen.

6.14 Run Qt 5.10.0 Demo with GPU acceleration

Run the following command

$ sudo qt5demo

6.15 Run Qt 5.10.0 Demo with OpenGL

Run the following command

. setqt5env
cd $QTDIR
cd /examples/opengl/qopenglwidget
./qopenglwidget

For more Qt 5.10.0 examples, please go to:
cd $QTDIR/examples/

6.16 Play HD Video with Hardware-decoding

gst-player is console player, it base on GStreamer, support VPU with Hardware-decoding:

sudo gst-player /home/pi/demo.mp4

The equivalent gsteamer command is as follows：

sudo gst-launch-1.0 filesrc location=/home/pi/demo.mp4 ! qtdemux name=demux demux. ! queue ! faad ! audioconvert ! audioresample ! alsasink device="hw:0,DEV=1" demux. ! queue ! h264parse ! nxvideodec ! nxvideosink dst-x=0 dst-y=93 dst-w=1280 dst-h=533

6.17 Connect to DVP Camera CAM500B

The CAM500B camera module is a 5M-pixel camera with DVP interface. For more tech details about it you can refer to Matrix - CAM500B.
Enter the following command to preview the video：

gst-launch-1.0 -e v4l2src device=/dev/video6 ! video/x-raw,format=I420,framerate=30/1,width=1280,height=720 ! nxvideosink

Enter the following command to start recording (VPU hardware encoding)：

gst-launch-1.0 -e v4l2src device=/dev/video6 ! video/x-raw,format=I420,framerate=30/1,width=1280,height=720 ! tee name=t t. \
 ! queue ! nxvideosink t. ! queue ! nxvideoenc bitrate=12000000 ! mp4mux ! \
 filesink location=result_720.mp4

6.18 Power Off and Schedule Power On

“PMU Power Management” feature helps us to auto power on the board at a specific time, it is implemented by an MCU, support software power-off, and RTC alarm power-up functions.

Here’s a simple guide:
Turn on automatically after 100 seconds. (Time must be greater than 60 seconds.):

$ sudo echo 100 > /sys/class/i2c-dev/i2c-3/device/3-002d/wakealarm

After setting up the automatic boot, turn off board with the 'poweroff’ command:

$ sudo poweroff

Cancel automatic boot:

$ sudo echo 0 > /sys/class/i2c-dev/i2c-3/device/3-002d/wakealarm

Query the current settings, in the front is current time, followed by the time of automatic booting: If no automatic boot is set, it will display "disabled”.

$ sudo cat /sys/class/i2c-dev/i2c-3/device/3-002d/wakealarm

Note that some older versions of hardware may not support this feature, if you don't see this file node in your system:
/sys/class/i2c-dev/i2c-3/device/3-002d/wakealarm
your board may be it does not support this feature.

6.19 Installing and Using OpenCV 4.1.2

OpenCV has been pre-installed in FriendlyCore (Version after 20191126) and does not require manual installation.
Please refre this link: https://github.com/friendlyarm/install-opencv-on-friendlycore/blob/s5pxx18/README.md
Quick test：

. /usr/bin/cv-env.sh
. /usr/bin/setqt5env-eglfs
cd /usr/local/share/opencv4/samples/python
python3 turing.py

6.20 Installing and Using Caffe

git clone https://github.com/friendlyarm/install-caffe-on-friendlycore
cd install-caffe-on-friendlycore
sudo ./install-caffe.sh

6.21 How to install and use docker (for armhf system)

6.21.1 How to Install Docker

Run the following commands：

sudo apt-get update
sudo apt-get install docker.io

6.21.2 Test Docker installation

Test that your installation works by running the simple docker image:

git clone https://github.com/friendlyarm/debian-jessie-arm-docker
cd debian-jessie-arm-docker
./rebuild-image.sh
./run.sh

7 Work with Android

7.1 Work with 4G Module EC20 under Android5

7.1.1 Hardware Setup

Connect an EC20 module to a USB to miniPCIe board and connect the board to an ARM board's USB Host. Here is a hardware setup:

Power on the board and you will be able to surf the internet with the 4G module like using an Android phone.

7.2 Modify the Android boot Logo

Replace the logo.bmp:

/opt/FriendlyARM/smart4418/android/device/friendly-arm/nanopi3/boot/logo.bmp
/opt/FriendlyARM/smart4418/android/device/friendly-arm/nanopi2/boot/logo.bmp

Replace the bootanimation.zip:

/opt/FriendlyARM/smart4418/android/device/friendly-arm/nanopi3/bootanimation.zip
/opt/FriendlyARM/smart4418/android/device/friendly-arm/nanopi2/bootanimation.zip

Re-compile android.

7.3 Use fastboot command to flash android firmware

Enter the uboot command line mode on the serial terminal when powering on, and then enter the following command:

fastboot 0

For S5P4418:

fastboot flash partmap partmap.txt
fastboot flash 2ndboot bl1-mmcboot.bin
fastboot flash fip-loader loader-mmc.img
fastboot flash fip-secure bl_mon.img
fastboot flash fip-nonsecure bootloader.img
fastboot flash boot boot.img
fastboot flash system system.img
fastboot flash cache cache.img
fastboot flash userdata userdata.img

For S5P6818:

fastboot flash partmap partmap.txt
fastboot flash 2ndboot bl1-mmcboot.bin
fastboot flash fip-loader fip-loader.img 
fastboot flash fip-secure fip-secure.img 
fastboot flash fip-nonsecure fip-nonsecure.img
fastboot flash boot boot.img
fastboot flash system system.img
fastboot flash cache cache.img
fastboot flash userdata userdata.img

7.4 Android Keys

Android 5:

  vendor/friendly-arm/nanopi3/security/

Android 7:

  build/target/product/security/

7.5 Optimizing HDMI Performance on Android 7

7.5.1 Note

By default, the driver initializes two framebuffers, one for the primary LCD display and the other for HDMI. If your project specifically requires the use of HDMI and not the LCD, you can follow the steps outlined in this chapter to make modifications. After making these changes, HDMI will be configured as the primary display, resulting in the initialization of only one framebuffer. This optimization conserves resources and leads to corresponding improvements in UI performance and boot speed.
The content of this chapter is applicable exclusively to S5P6818 running Android 7. For S5P4418, the modification process is similar, with adjustments needed in the corresponding files.

7.5.2 Modify the kernel

You need to modify the kernel Device Tree Source (DTS) to disable the dp_drm_lvds node, as shown below:

--- a/arch/arm64/boot/dts/nexell/s5p6818-nanopi3-common.dtsi
+++ b/arch/arm64/boot/dts/nexell/s5p6818-nanopi3-common.dtsi
@@ -810,6 +810,7 @@
                        plane-names = "video", "rgb", "primary";
                };
                port@1 {
+                       status = "disabled";
                        reg = <1>;
                        back_color = < 0x0 >;
                        color_key = < 0x0 >;
@@ -820,7 +821,7 @@
 
 &dp_drm_lvds {
        remote-endpoint = <&lcd_panel>;
-       status = "ok";
+       status = "disabled";
 
        display-timing {
                clock-frequency = <50000000>;

After compilation, you will obtain a new arch/arm64/boot/dts/nexell/s5p6818-nanopi3-rev*.dtb file.
During the testing phase, you can directly update it to the board using adb with the following command:

adb root; adb wait-for-device; adb shell mkdir /storage/sdcard1/; adb
shell mount -t ext4 /dev/block/mmcblk0p1 /storage/sdcard1/
adb push arch/arm64/boot/dts/nexell/s5p6818-nanopi3-rev*.dtb /storage/sdcard1/

For a complete firmware update, you will need to replace the files in the device/friendlyelec/nanopi3/boot directory of the Android 7 source code.

7.5.3 Modify env.conf

To modify the device/friendlyelec/nanopi3/boot/env.conf file and add a line

lcdtype     HDMI1080P60

This mode needs to match the mode detected by Android 7 after startup; otherwise, it may result in a prolonged black screen state or even no display output. In such cases, you may need to manually set it in the U-Boot command-line environment:

setenv lcdtype HDMI1080P60; saveenv; reset

7.5.4 Modify system.prop

To modify the device/friendlyelec/nanopi3/system.prop file in Android 7

ro.sf.lcd_density=240

Alternatively, you can adjust the system property or experiment with different values that you deem more appropriate. You can also use the following command to change the display density under the serial or adb environment and observe if the effect is suitable:

adb shell wm density 240

7.5.5 Compiling Android

Follow the instructions in the wiki to compile Android 7 and conduct testing. If you encounter any exceptions, please carefully review the preceding steps.

8 Make Your Own OS Image

8.1 Install Cross Compiler

8.1.1 Install arm-linux-gcc 4.9.3

Download the compiler package:

git clone https://github.com/friendlyarm/prebuilts.git -b master --depth 1
cd prebuilts/gcc-x64
cat toolchain-4.9.3-armhf.tar.gz* | sudo tar xz -C /

Then add the compiler's directory to "PATH" by appending the following lines in "~/.bashrc":

export PATH=/opt/FriendlyARM/toolchain/4.9.3/bin:$PATH
export GCC_COLORS=auto

Execute "~/.bashrc" to make the changes take effect. Note that there is a space after the first ".":

. ~/.bashrc

This compiler is a 64-bit one therefore it cannot be run on a 32-bit Linux machine. After the compiler is installed you can verify it by running the following commands:

arm-linux-gcc -v
Using built-in specs.
COLLECT_GCC=arm-linux-gcc
COLLECT_LTO_WRAPPER=/opt/FriendlyARM/toolchain/4.9.3/libexec/gcc/arm-cortexa9-linux-gnueabihf/4.9.3/lto-wrapper
Target: arm-cortexa9-linux-gnueabihf
Configured with: /work/toolchain/build/src/gcc-4.9.3/configure --build=x86_64-build_pc-linux-gnu
--host=x86_64-build_pc-linux-gnu --target=arm-cortexa9-linux-gnueabihf --prefix=/opt/FriendlyARM/toolchain/4.9.3
--with-sysroot=/opt/FriendlyARM/toolchain/4.9.3/arm-cortexa9-linux-gnueabihf/sys-root --enable-languages=c,c++
--with-arch=armv7-a --with-tune=cortex-a9 --with-fpu=vfpv3 --with-float=hard
...
Thread model: posix
gcc version 4.9.3 (ctng-1.21.0-229g-FA)

8.2 Compile Linux kernel for FriendlyCore/Lubuntu/EFlasher

8.2.1 Compile Kernel

• Download Kernel Source Code

git clone https://github.com/friendlyarm/linux.git -b nanopi2-v4.4.y --depth 1
cd linux

The NanoPi-Fire2A's kernel source code is in the "nanopi2-v4.4.y" branch.You need to switch to this branch.

• Compile Ubuntu Kernel

touch .scmversion
make ARCH=arm nanopi2_linux_defconfig
make ARCH=arm

After your compilation succeeds an "arch/arm/boot/zImage" will be generated and a DTB file(s5p4418-nanopi2-rev*.dtb) will be generated in the "arch/arm/boot/dts/" directory. You can use them to replace the existing zImage and DTB files in the boot partition of your bootable SD card.

8.2.2 Use Your Generated Kernel

• Update kernel in SD card

If you use an SD card to boot Ubuntu you can copy your generated zImage and DTB files to your SD card's boot partition(e.g. partition 1 /dev/sdX1).

• Update kernel in eMMC

If you boot your board from eMMC you can update your kernel file by following the steps below:
1) Usually after OS is loaded eMMC's boot partition (in our example eMMC's device name was /dev/mmcblk0p1) will be automatically mounted and you can verify that by running "mount"
2) Connect your board to a host PC running Ubuntu and copy the zImage and DTB files to eMMC's boot partition
3) Or you can copy your generated kernel file to an external storage card(e.g. an SD card or a USB drive), connect the storage card to your board the move the file from the card to eMMC's boot partition
4) After update is done type "reboot" to reboot your board. Note: don't just directly disconnect your board from its power source or press the reset button to reboot the board. These actions will damage your kernel file

• Generate Your boot.img

Refer to this repo: https://github.com/friendlyarm/sd-fuse_s5p4418

8.3 Compile Linux kernel for Android7

The Android 7.1.2 source code already contains the pre-compiled kernel. If you need to customize it, you can compile the kernel according to the following guide.

git clone https://github.com/friendlyarm/linux.git -b nanopi2-v4.4.y --depth 1
cd linux
touch .scmversion
make ARCH=arm nanopi2_nougat_defconfig
make ARCH=arm

The newly generated kernel is arch/arm/boot/zImage，The new DTB file is also included under the directory arch/arm/boot/dts/.(s5p4418-nanopi2-rev*.dtb).
If you only want to debug the kernel, you can quickly update it with adb:

adb root; adb shell mkdir /storage/sdcard1/; adb shell mount -t ext4 /dev/block/mmcblk0p1 /storage/sdcard1/;
adb push arch/arm/boot/zImage arch/arm/boot/dts/s5p4418-nanopi2-rev*.dtb /storage/sdcard1/

If you want to generate boot.img for burning, you can copy the kernel zImage and DTB files to the Android7 source code directory: device/friendlyelec/nanopi2/boot, then recompile Android7.

8.4 Compile U-Boot for Android7/FriendlyCore/Lubuntu/EFlasher

Download the U-Boot source code and compile it. Note that the github's branch is nanopi2-v2016.01:

git clone https://github.com/friendlyarm/u-boot.git 
cd u-boot
git checkout nanopi2-v2016.01
make s5p4418_nanopi2_defconfig
make CROSS_COMPILE=arm-linux-

After your compilation succeeds a bootloader.img will be generated. If you want to test it flash it to your installation SD card to replace an existing U-Boot v2016.01 file via fastboot, sd-fuse_s5p4418 or eflasher ROM.
For Android7: Copy bootloader.img to Android7 source directory device/friendlyelec/nanopi2/boot, then recompile Android7.
Note: you cannot use mixed U-Boot files. For example you cannot use fastboot to update an existing U-Boot V2014.07 and you cannot use bootloader.img to replace an existing u-boot.bin

8.5 Compile Android 7.1.2

8.5.1 Install Cross Compiler

Install 64 bit Ubuntu 16.04 on your host PC.

sudo apt-get install bison g++-multilib git gperf libxml2-utils make python-networkx zip
sudo apt-get install flex curl libncurses5-dev libssl-dev zlib1g-dev gawk minicom
sudo apt-get install openjdk-8-jdk
sudo apt-get install exfat-fuse exfat-utils device-tree-compiler liblz4-tool

For more details refer to https://source.android.com/source/initializing.html 。

8.5.2 Download Android7 Source Code

There are two ways to download the source code:

• repo archive file on netdisk

Netdisk URL: Click here
File location on netdisk：sources/s5pxx18-android-7.git-YYYYMMDD.tar (YYYYMMDD means the date of packaging)
After extracting the repo package from the network disk, you need to execute the sync.sh script, which will pull the latest code from gitlab:

tar xvf /path/to/netdisk/sources/s5pxx18-android-7.git-YYYYMMDD.tar
cd s5pxx18-android-7
./sync.sh

• git clone from gitlab

NanoPi-Fire2A source code is maintained in gitlab, You can download it by running the following command:

git clone https://gitlab.com/friendlyelec/s5pxx18-android-7.git -b master

8.5.3 Compile Android7

cd s5pxx18-android-7
source build/envsetup.sh
lunch aosp_nanopi2-userdebug
make -j8

After your compilation succeeds the following files will be generated in the "out/target/product/nanopi2/" directory.

filename	partition	Description
bl1-mmcboot.bin	raw	boot firmware
loader-mmc.img	raw	boot firmware
bl_mon.img	raw	boot firmware
bootloader.img	raw	uboot-v2016.01
env.conf	-	Uboot environment variable containing Android kernel command line parameters
boot.img	boot	kernel zImage, DTBs; logo; Android ramdisk
cache.img	cache	-
userdata.img	userdata	-
system.img	system	-
partmap.txt	-	Partition description file

9 Build Kernel Headers Package

The following commands need to be executed on the development board:

9.1 Software Version

The OS image file name: s5p4418-sd-friendlycore-xenial-4.4-armhf-YYYYMMDD.img, s5p4418-eflasher-friendlycore-xenial-4.4-armhf-YYYYMMDD.img

pi@NanoPC-T2:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.6 LTS
Release:        16.04
Codename:       xenial
pi@NanoPC-T2:~$ cat /proc/version
Linux version 4.4.172-s5p4418 (root@jensen) (gcc version 7.5.0 (ctng-1.24.0-108g-FA) ) #1 SMP PREEMPT Wed Mar 24 15:17:25 CST 2021

9.2 Install the required packages

sudo apt-get update
sudo apt-get install -y dpkg-dev bsdtar

9.3 Build Kernel Headers Package

git clone https://github.com/friendlyarm/linux -b nanopi2-v4.4.y --depth 1 kernel-s5pxx18-arm
cd kernel-s5pxx18-arm
rm -rf .git
make distclean
touch .scmversion
make CROSS_COMPILE= ARCH=arm nanopi2_linux_defconfig
alias tar=bsdtar
make CROSS_COMPILE= ARCH=arm bindeb-pkg -j4

The following message is displayed to indicate completion:

dpkg-deb: building package 'linux-firmware-image-4.4.172-s5p4418' in '../linux-firmware-image-4.4.172-s5p4418_4.4.172-s5p4418-1_armhf
.deb'.
dpkg-deb: building package 'linux-headers-4.4.172-s5p4418' in '../linux-headers-4.4.172-s5p4418_4.4.172-s5p4418-1_armhf.deb'.
dpkg-deb: building package 'linux-libc-dev' in '../linux-libc-dev_4.4.172-s5p4418-1_armhf.deb'.
dpkg-deb: building package 'linux-image-4.4.172-s5p4418' in '../linux-image-4.4.172-s5p4418_4.4.172-s5p4418-1_armhf.deb'.
dpkg-genchanges: binary-only upload (no source code included)

10 Installation=

sudo rm -f /lib/modules/4.4.172-s5p4418/build
sudo rm -f /lib/modules/4.4.172-s5p4418/source
sudo dpkg -i ../linux-headers-4.4.172-s5p4418_4.4.172-s5p4418-1_armhf.deb

10.1 Testing

To compile the pf_ring module as an example, refer to the documentation: https://www.ntop.org/guides/pf_ring/get_started/git_installation.html.

git clone https://github.com/ntop/PF_RING.git
cd PF_RING/kernel/
make CROSS_COMPILE=

After compiling, use insmod to try to load the module:

sudo insmod ./pf_ring.ko

11 Connect NanoPi-Fire2A to External Modules

11.1 Connect NanoPi-Fire2A to USB Camera(FA-CAM202)

• In this use case the NanoPi-Fire2A runs Debian. If you connect your NanoPi-Fire2A to our LCD or an HDMI monitor after Debain is fully loaded click on "other"-->"xawtv" on the left bottom of the GUI and the USB Camera application will be started. After enter "welcome to xawtv！" click on "OK" to start exploring.

11.2 Connect NanoPi-Fire2A to CMOS 5M-Pixel Camera

For more details about the CAM500A camera refer to [1]

• If your NanoPi-Fire2A runs Android5.1 and it is connected to our LCD or an HDMI monitor after Android is fully loaded click on the "Camera" icon and the application will be started. You can take pictures or record videos

• Under Debian a camera utility "nanocams" is available for previewing 40 frames and picture taking. You can try it by following the commands below

sudo nanocams -p 1 -n 40 -c 4 -o IMG001.jpg

For more details about the usage of the nanocams run "nanocams -h". You can get its source code from our git hub:

git clone https://github.com/friendlyarm/nexell_linux_platform.git

• Under FriendlyCore (kernel 4.4), You can try it by following the commands below:

Enter the following command to preview the video：

gst-launch-1.0 -e v4l2src device=/dev/video6 ! video/x-raw,format=I420,framerate=30/1,width=1280,height=720 ! nxvideosink

Enter the following command to start recording (VPU hardware encoding)：

gst-launch-1.0 -e v4l2src device=/dev/video6 ! video/x-raw,format=I420,framerate=30/1,width=1280,height=720 ! tee name=t t. \
 ! queue ! nxvideosink t. ! queue ! nxvideoenc bitrate=12000000 ! mp4mux ! \
 filesink location=result_720.mp4

11.3 Use OpenCV to Access USB Camera

• The full name of "OpenCV" is Open Source Computer Vision Library and it is a cross platform vision library.
• When the NanoPi-Fire2A runs Debian users can use OpenCV APIs to access a USB Camera device.
  

1. Here is a guideline on how to use OpenCV with C++ on the NanoPi-Fire2A:

• Firstly you need to make sure your NanoPi-Fire2A is connected to the internet.Login to your NanoPi-Fire2A via a serial terminal or SSH. After login type in your username(root) and password(fa):
• Run the following commands:

apt-get update
apt-get install libcv-dev libopencv-dev

2. Make sure your USB camera works with the NanoPi-Fire2A. You can test your camera with NanoPi-Fire2A's camera utility.

3. Check your camera device:

ls /dev/video*

• Note:in our test case video0 was the device name.

4. OpenCV's code sample(official code in C++) is under /home/fa/Documents/opencv-demo. Compile the code sample with the following commands:

cd /home/fa/Documents/opencv-demo
make

After it is compiled successfully a "demo" executable will be generated

5. Connect NanoPi-Fire2A to USB Keyboard & Run the Following Command:

./demo

opencv is successfully started

11.4 Connect NanoPi-Fire2A to Matrix GPS Module

• The Matrix-GPS module is a small GPS module with high performance. It can be used in navigation devices, four-axle drones and etc.
• The Matrix-GPS module uses serial communication. When the NanoPi-Fire2A is connected to the Matrix GPS module, after the NanoPi-Fire2A is powered up type in the following command in a terminal or click on the xgps icon it will be started.

$su - fa -c "DISPLAY=:0 xgps 127.0.0.1:9999"

• Or on the Debian GUI start the LXTerminal, type in "xgps" and enter it will be started too.

For more details about this GPS module refer to Click to check
Refer to the following diagram to connect the NanoPi-Fire2A to the Matrix-GPS:

Connection Details:

12 Access Hardware under Android

FriendlyElec developed a library called “libfriendlyarm-things.so”, for android developer to access the hardware resources on the development board in their android apps, the library is based on Android NDK.
Accessible Modules:

• Serial Port
• PWM
• EEPROM
• ADC
• LED
• LCD 1602 (I2C)
• OLED (SPI)

Interfaces & Ports:

• GPIO
• Serial Port
• I2C
• SPI

Refer to the following url for details：

• Homepage: http://wiki.friendlyelec.com/wiki/index.php/FriendlyThings
• Examples: https://github.com/friendlyarm/friendlythings-examples
• Guide to API: http://wiki.friendlyelec.com/wiki/index.php/FriendlyThings_APIs

13 Connect NanoPi-Fire2A to FriendlyARM LCD Modules

• Android

Here are the LCDs that are supported under Android:S430, S700/S701, S702, HD700, HD702, HD101 and X710 all of which are LCDs with capacitive touch.

• FriendlyCore & Lubuntu Desktop

Here are the LCDs that are supported under FriendlyCore and Lubuntu Desktop:S430, S700/S701, S702, HD700, HD702, HD101 and X710 all of which are LCDs with capacitive touch;
W35B, H43, P43, S70D and Matrix 2.8" SPI Key TFT LCD all of which are LCDs with resistive touch
All these LCD's tech details can be obtained on our wiki site:LCDModules

14 Schematics & Mechanical drawing

• Schematic(NanoPi Fire3_2A 1709 Schematic.pdf)
• PCB Dimension(NanoPi_Fire_3_2A_1709_Drawing(dxf).zip)
• S5P4418 Datasheet (S5P4418_Datasheet_0.1.pdf)

15 Resources

• 《创客秘籍》Hacker's Book in Chinese by FriendlyARM
• 《创客秘籍-02》Hacker's Book-02 in Chinese by FriendlyARM
• 《创客秘籍-03》Hacker's Book-03 in Chinese by FriendlyARM
• SEC_Users_Manual_S5P4418_Users_Manual_Preliminary[2]
• eMMC eMMC5.0_1xnm_based_e_MMC
• Matrix Modules & Wiki Sites:
  • Button
  • LED
  • A/D Converter
  • Relay
  • 3-Axis Digital Accelerometer
  • 3-Axis Digital Compass
  • Temperature Sensor
  • Temperature & Humidity Sensor
  • Buzzer
  • Joystick
  • I2C(PCF8574)+LCD1602
  • Sound Sensor
  • Ultrasonic Ranger
  • GPS
  • Matrix - Compact Kit
  • Fire Sensor
  • CAM500A Camera
  • BAll Rolling Switch
  • 2'8 SPI Key TFT 2.8" SPI LCD
  • IR Counter
  • IR Receiver
  • L298N Motor Driver
  • MQ-2 Gas Sensor
  • MQ-3 Gas Sensor
  • One_Touch_Sensor
  • _Photoresistor
  • _Potentiometer
  • Pressure & Temperature Sensor
  • RGB LED
  • RTC
  • Rotary Encoder
  • Soil Moisture Sensor
  • Thermistor
  • USB WiFi
  • Water Sensor

16 Source Code and Image Files Download Links

• Image File: [3]
• Source Code: [4]

17 Tech Support

If you have any further questions please visit our forum http://www.friendlyarm.com/Forum/ and post a message or email us at techsupport@friendlyarm.com. We will endeavor to get back to you as soon as possible.

18 Update Log

18.1 2023-01-09

18.1.1 FriendlyCore：

• optimized the systemd service

18.2 2020-10-26

• FriendlyCore, Lubuntu：

Fix Bluetooth stability issue

18.3 2019-12-28

• eflasher：

1) Supports flashing only some files, such as updating only the kernel and uboot in emmc
2) Added gui option to disable overlay filesystem
3) Add command line parameters to achieve one-click installation without interaction
4) Fix the issue that the same mac address will appear on different devices after backup and restore image
5) UI interface can now be configured with title, hide interface menus and buttons

18.4 2019-11-26

• FriendlyCore:

Pre-installed OpenCV 4.1.2

18.5 2019-11-14

• Introducing a new system FriendlyWrt:

FriendlyWrt is a customized OpenWrt system developed by FriendlyElec. It is open source and suitable for applications in IoT, NAS etc.
Please refre: http://wiki.friendlyelec.com/wiki/index.php/How_to_Build_FriendlyWrt

• FriendlyCore, Lubuntu updated as follows:

1) Added support for new 4.3-inch screen YZ43
2) Compile bcmdhd as a module.

• Android7 update is as follows:

1) Added support for new 4.3-inch screen YZ43
2) Optimize the touch experience when using HD900 screen under Android 7 system
3) Optimize the touch experience when using S702 screen under Android 7 system

18.6 2019-10-18

• Android7, FriendlyCore, Lubuntu：

Fixed audio playback issue.

18.7 2019-09-30

• Android7 updated as follows:

1）Added support for Android hardware access library (named FriendlyThing), support access to hardware resources such as GPIO, PWM, RTC, serial port and watchdog, providing open source demo
2) Added support for camera CAM500B (OV5640)
3) Added support for LCD W500 (800x480)
4) Fixed LCD-S430 compatibility issues

• FriendlyCore, FriendlyDesktop updated as follows:

1) Kernel version updated to v4.4.172, same as Android 7
2) Added Docker support, support 32bit and 64bit file systems
3) Kernel configuration items are optimized to enable more features and device drivers

18.8 2019-07-18

• Introducing a new system Android 7.1.2

1) Features similar to the old version of Android 5, support 4G, WiFi, Ethernet, Bluetooth, etc.
2) Kernel version: 4.4.172
3) Known issue: The camera is not working yet

• Android/FriendlyCore/Lubuntu updated as follows：

1) Fix an issue where HD101B can't be touched in some cases
2) Fix GPIO configuration of Power key
3) Solve the problem of too small volume: the volume of the DAC is changed from -20dB to -6dB during playback.
4) Add more models of USB Wi-Fi support, built-in driver rtl8821CU.ko, rtl88XXau.ko

• Updates for Lubuntu only：

1) Modify Lubuntu's Power key behavior to (without pop-ups) shut down directly
2) Add script xrotate.sh to simplify screen rotation settings (Note: screen rotation will lose performance)

• The following updates are only available for NanoPC T2, Smart4418:

Support for reading Ethernet Mac addresses from the onboard EEPROM, only supports the following systems: FriendlyCore, Lubuntu, Android7

18.9 2019-06-25

Linux(Ubuntu 16.04/18.04) uses OverlayFS to enhance filesystem stability.

18.10 2019-06-03

1) Configure LED1 to be in heartbeat mode
2) Fix HDMI 1080P may have no display problem in some cases
3) Fix the issue that mysql cannot be installed under Linux
4) Fix the issue that the 1-wire touch resistance screen cannot be used under lubuntu

18.11 2019-01-24

1) Update uboot-v2014.07, uboot-v2016.01 for HD702V LCD
2) Adjust Qt5 font path

18.12 2018-12-17

• Android5 updated as follows:

1) Add support for 4G network, support module: Quectel EC20
2) Add audio setting UI, you can set the default output to headphones or HDMI
3) Synchronously turn off the backlight of the one-line touch screen when the system Shutdown

• FriendlyCore updated as follows:

1) Add OV5640 camera support
2) Update BL1 to improve system startup stability

• Lubuntu updated as follows:

1) Add Chrome-browser browser, support web page 1080P hardware decoding, support WebGL
2) Set the audio output channel to HDMI by default (can be changed via /etc/asound.conf)
3) Update BL1 to improve system startup stability
4) Fixed some issues regarding the package error in the previous version
5) Adjust DPMS settings, turn off automatic sleep by default

18.13 March-04-2016

• Released English version

18.14 March-09-2016

• Corrected a typo

18.15 March-23-2016

• Added section 11

18.16 March-27-2016

• Corrected expression errors

18.17 April-08-2016

• Added section 6.4.2 and 7.4
• Updated section 6.5

18.18 June-30-2016

• Added section 9 and 10

18.19 Sep-04-2016

• Updated section 5.2.2 and 10.1.1

18.20 Sep-27-2016

• Updated section 5.2.2, 7.5 and 8.2

18.21 Nov-2-2016

• Updated section 6.2, 6.3, 6.4 and 12

18.22 Nov-17-2016

• Added section 10.6

18.23 Dec-7-2016

• Added section 6.6
• Updated section 7.5

18.24 June-13-2016

• Added section 7: added UbuntuCore
• Added section 11.3: added DietPi

18.25 June-20-2016

• Updated sections 6.2 & 6.3: Wireless connection and WiFi AP setting
• Added section 3: software features