Basic knowledge:

• CORE9G25-CON
  • Getting started with CORE9G25-CON Board
• Discover the IP address assigned by DHCP
• Installing Bonjour
• SCP to remotely browse the SD file system
• FTP to remotely browse the microSD file system
• Using the SSH session
• WEB access
• Debug Serial Port Interface

How-tos:

• Set eth0 with a static IP address

  By default each CORE9G25 board get the IP address from the DHCP server on your LAN. To define instead a static IP address replace in /etc/network/interfaces these lines: allow-hotplug eth0 iface eth0 inet dhcp with: allow-hotplug eth0 iface eth0 inet static address 192.168.1.90 netmask 255.255.255.0 gateway 192.168.1.1

• Get the IP address from DHCP manually

  If you need to get the IP address manually from the DHCP server on your LAN simply shut down the eth0 interface: ~# ifdown eth0 Internet Systems Consortium DHCP Client 4.1.1-P1 Copyright 2004-2010 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Listening on LPF/eth0/00:04:25:a8:9d:5e Sending on LPF/eth0/00:04:25:a8:9d:5e Sending on Socket/fallback DHCPRELEASE on eth0 to 10.55.98.1 port 67 eth0: link down and bring it back up by typing: ~# ifup eth0 Internet Systems Consortium DHCP Client 4.1.1-P1 Copyright 2004-2010 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ ADDRCONF(NETDEV_UP): eth0: link is not ready Listening on LPF/eth0/00:04:25:a8:9d:5e Sending on LPF/eth0/00:04:25:a8:9d:5e Sending on Socket/fallback eth0: link up (100/Full) ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4 DHCPOFFER from 10.55.98.1 DHCPREQUEST on eth0 to 255.255.255.255 port 67 DHCPACK from 10.55.98.1 bound to 10.55.98.19 -- renewal in 33627 seconds. it comes up and grabs its IP (in this case 10.55.98.19 )

• Set the system date

  Your CORE9G25 board has two clocks: One called System Clock that is a software clock maintained by the Linux Operating System Another one called Real Time Clock (RTC) and implemented in hardware inside the Atmel CPU. This clock is powered by a Lithium battery to mantain the clock alive when the main power supply is off. Setting the System Clock date is the Linux command to manage the systems clock. To read the currently System Clock type: ~# date Fri Oct 8 17:44:42 CEST 2010 To set it type: ~# date -s "8 OCT 2010 18:45:00" Fri Oct 8 18:45:00 CEST 2010 This time is active until the main power supply board is on. When off the system clock is lost. Setting the Real Time Clock To read the Hardware Clock type: ~# hwclock -r Fri Oct 8 17:46:43 2010 -0.004115 seconds To set the Hardware Clock using the System Clock current time type: ~# hwclock -w Now check it typing: ~# date Fri Oct 8 18:49:02 CEST 2010 ~# hwclock -r Fri Oct 8 18:49:10 2010 -0.004076 seconds

• Change the hostname

  When you get access to the CORE9G25 board command line the prompt is something like this: CORE9G25:~# Where CORE9G25 is the current hostname. If more CORE9G25 boards or other Linux systems are reacheable on your LAN it could be important to have different hostnames tfor each board to avoid for example to give commands to the wrong system. The hostname is saved in /etc/hostname. Change it for example with myboard by typing: ~# echo "myboard" > /etc/hostname ~# /etc/init.d/hostname.sh start then logout typing: ~# logout and login again. The prompt will be: myboard:~# The hostname is very important also when using Bonjour to get the right IP address to the CORE9G25 board in form of http://myboard.local.

• USB memories automount

  This article explains how to automount an USB stick when inserted and unmount it automatically when unplugged Install the required packages The automounter facility is managed by autofs. Autofs controls the operation of the automount daemons. The automount daemons automatically mount filesystems when they are used and unmount them after a period of inactivity. This is done based on a set of pre-configured maps. To install autofs type: ~# apt-get update ~# apt-get install autofs Configure autofs Insert an USB stick and check on which device it appears by typing: ~# dmesg ... usb 1-2: new full speed USB device using at91_ohci and address 2 scsi0 : usb-storage 1-2:1.0 scsi 0:0:0:0: Direct-Access UDISK PDU01-8G 8AH2.0 0.00 PQ: 0 ANSI: 2 sd 0:0:0:0: [sda] 15794176 512-byte logical blocks: (8.08 GB/7.53 GiB) ... sd 8:0:0:0: [sda] Assuming drive cache: write through sda: ... In this case the device is /dev/sda. If your USB stick has more than one partition you will see sda1, sda2, etc. for each partition. Edit the file /etc/auto.master adding this line: /var/autofs/removable /etc/auto.removable --timeout=2 Where: /var/autofs/removable is the directory where your USB stick will be mounted /etc/auto.removable is another file that we have to create --timeout=2 tells that the device will be umounted after 2 seconds of idling Now create the file /etc/auto.removable with this contents: usbstick -fstype=vfat,rw,umask=002 :/dev/sda then restart autofs typing: ~# /etc/init.d/autofs restart Now move to the /var/autofs/removable directory: ~# cd /var/autofs/removable /var/autofs/removable# ls /var/autofs/removable# ls usbstick [ .. list on my files on the usbstick ] As you can see the usbstick directory will appear when requested and disappear after 2 seconds. Related links AutoFs doc from Debian The article from which I drew inspiration for this tip Autofs Man pages

• Change the speed and duplex settings of the Ethernet port

  Change the Ethernet setting on the fly To change the Ethernet parms on the fly type this command: ~# mii-tool [-F mode] eth0 ... Where mode can be: 100baseTx-HD 100baseTx-FD 10baseT-HD 10baseT-FD The setting will be valid until the next system reboot. Mii-tool Man page Change the Ethernet setting at the end Edit the /etc/network/interfaces file and the bold line if you are using the dchp: auto eth0 iface eth0 inet dhcp up mii-tool -F 10baseT-HD eth0 or this line if you are using a static IP configuration: auto eth0 iface eth0 inet static address 192.168.1.10 netmask 255.255.255.0 gateway 192.168.1.1 up mii-tool -F 10baseT-HD eth0 the reboot or type: ~# ifdown eth0 ... ~# ifup eth0 ...

• Read the microSD serial number

  Enter the SD Card ~# cd /sys/class/mmc_host/mmc?/mmc?:* /sys/class/mmc_host/mmc0/mmc0:aaaa# cat serial 0x015c5340 A lot of other info are available: /sys/class/mmc_host/mmc0/mmc0:aaaa# ls -al total 0 drwxr-xr-x 4 root root 0 Jun 27 15:37 . drwxr-xr-x 4 root root 0 Jun 27 15:37 .. drwxr-xr-x 3 root root 0 Jun 27 15:37 block -r--r--r-- 1 root root 4096 Jun 28 07:18 cid -r--r--r-- 1 root root 4096 Jun 28 07:28 csd -r--r--r-- 1 root root 4096 Jun 28 07:28 date lrwxrwxrwx 1 root root 0 Jun 27 15:37 driver -> ../../../../../../bus/mmc/drk -r--r--r-- 1 root root 4096 Jun 28 07:28 erase_size -r--r--r-- 1 root root 4096 Jun 28 07:21 fwrev -r--r--r-- 1 root root 4096 Jun 28 07:21 hwrev -r--r--r-- 1 root root 4096 Jun 28 07:21 manfid -r--r--r-- 1 root root 4096 Jun 27 15:37 name -r--r--r-- 1 root root 4096 Jun 28 07:18 oemid drwxr-xr-x 2 root root 0 Jun 28 07:28 power -r--r--r-- 1 root root 4096 Jun 28 07:28 preferred_erase_size -r--r--r-- 1 root root 4096 Jun 28 07:28 scr -r--r--r-- 1 root root 4096 Jun 27 15:37 serial lrwxrwxrwx 1 root root 0 Jun 27 15:37 subsystem -> ../../../../../../bus/mmc -r--r--r-- 1 root root 4096 Jun 28 07:28 type -rw-r--r-- 1 root root 4096 Jun 27 15:37 uevent Related links RPi SD cards Bunnie:studios blog MicroSD card FAQ Samsung SD & MicroSD Card product family Samsung memory store

• Disable the system logs

  Disable rsyslog The most part of application program log created on /var/log are created by rsyslog daemon. To disable it type: ~# cd /etc/rc2.d /etc/rc2.d# mv S01rsyslog K01rsyslog Disable /var/log/dmesg The system message log on /var/log/dmesg is created by bootlogs daemon. To disable it type: ~# cd /etc/rc2.d /etc/rc2.d# mv S01bootlogs K01bootlogs Disable /var/log/lastlog Comment the line: session optional pam_lastlog.so in /etc/pam.d/login.

• Deleting the cache of package files to save space

  The Debian package installation utility apt-get keeps all the packages it has downloaded in case they are needed in the future in /var/cache/apt/archives directory. It is possible to save space removing them by typing: ~#apt-get clean

• Reserve

Programming languages

This is a selection of "Hello World !" examples in all the languages we tried on the CORE9G25 boards:

• Hello World in C
• Hello World in C++
• Hello World in Python
• Hello World in Java
• Hello World in PHP
• Hello World in Perl
• Hello World in NodeJS
• Hello World in Shell scripting
• Hello World in Lua
• Hello World in YaBasic

Linux Kernel 3.11 and EmDebian "7.1" Wheezy

• Bootloader: Compiling AT91Bootstrap for CORE9G25
• Linux Kernel image: Compiling the Linux Kernel 3.11.6 for the CORE9G25
• Rootfs: Build an Embedded Debian Grip 7.2 root filesystem

Bootable microSD:

• MicroSD card repository
• How to create a bootable microSD from binary repositories

Embedded peripherals

• GPIO lines
• RS232 and RS422 lines
• RS485 lines
• Using the PWM lines
• SPI bus interface
• I2C bus interface
• 1-wire lines
• A/D converter lines
• CORE9G25 wiring examples

USB peripherals

• Webcam:
  • Video streaming over HTTP
  • Time-laps video
• Wi-Fi USB adapters
• Bluetooth USB adapter

Programming examples

• Programming examples with Python
• Install the ARM9 cross toolchain to compile the Linux Kernel and AT91Bootstrap
• Hello world example from a Linux Device driver

Web programming

• Server side using Python
  • Install and test Tornado to write web services in Python
  • Control a led remotely using Tornado web server
• Client side using Javascript
  • Sample Application with Angular.js
• Server side using C
  • CGI written in C

SQL databases

• MySQL server installing and test
• MySQL client API in C, Python and PHP
• Access to MySQL Server using MySQL Query browser
• SQLite installing and test

Miscellaneous

• How to install Shell In a Box
• How to create mini WiFi Webapp server
• Remote control using OpenRemote
• Remote control using TouchOSC