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GNUBLIN-LAN

From GNUBLIN

GNUBLIN-LAN SCHRAEGBILD 001.jpg


Contents

Technical details

  • ARM 9 180 MHz processor
  • 32 MB SDRAM
  • MicroSD cards (up to 32GB) Operating system / kernel / user data
  • 1 x RJ45 network port (via ENC28J60)
  • 1 x integrated USB console (USB to RS232 converter)
  • 1 x relay on-board
  • 1 x RTC (clock with battery)
  • GNUBLIN Connector
  • 1 x LED on GPIO controlled 3
  • Power LED
  • Various boot options (SD Card, DFU or RS232)
  • External 7-12 V power supply via hollow socket (optional)
  • USB OTG (host or device)

Links & Datasheets

Interfaces and components

To get an overview of which components and interfaces are located on the GNUBLIN LAN, helps the figure below. A detailed description of the pin and pin assignment, see below. NOTE: In the hollow socket for the external power supply is the ground inside!

GNUBLIN-LAN uebersicht.png

Settings

As mentioned above, various settings can be made on the board. So it is possible, using the boot option jumper to influence the power supply (USB or external) or the USB option (device to host or device). The following diagram shows since that configuration option.

GNUBLIN STANDARD STECKER JUMPER.png


configure LAN

The LAN chip ENC28J60 on the Gnublin-LAN board is connected via the SPI interface. In order to use this, you first must load the driver with:

modprobe enc28j60 irq_pin=12 cs_pin=19

If it worked, the output of:

ifconfig -a

should including the eth0 interface.

To obtain DHCP server for an IP address, you give the following command:

dhclient eth0

In order to test the whole now, any PC in the local network or a remote Internet server can be pinged.

ping google.de

The output is now obtained for example (the ping program terminates with ctrl + c) the following:

PING google.de (173.194.69.94) 56(84) bytes of data.
64 bytes from bk-in-f94.1e100.net (173.194.69.94): icmp_req=1 ttl=49 time=44.3 ms
64 bytes from bk-in-f94.1e100.net (173.194.69.94): icmp_req=2 ttl=49 time=44.7 ms
64 bytes from bk-in-f94.1e100.net (173.194.69.94): icmp_req=3 ttl=49 time=43.3 ms
64 bytes from bk-in-f94.1e100.net (173.194.69.94): icmp_req=4 ttl=49 time=43.4 ms
--- google.de ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 43.308/43.968/44.784/0.673 ms


HINT:

Automatically load drivers

If the enc28j60 drivers should be automatically loaded at boot time, you must enter

enc28j60 irq_pin=12 cs_pin=19

in the file /etc/modules. This is done most easily using the text editor nano in the terminal directly on the Gnublin.

nano /etc/modules


Static IP at boot

File /etc/network/interfaces at Gnublin:

## Ethernet Schnittstelle 0
auto eth0  
iface eth0 inet static
    address 192.168.0.97   
    netmask 255.255.255.0  
    gateway 192.168.0.1

dynamic IP at boot

File /etc/network/interfaces at Gnublin:

## Ethernet Schnittstelle 0
auto eth0  
iface eth0 inet dhcp
    hwaddress ether ba:07:1b:0c:64:0e

Gnublin always gets a different IP address from the DHCP

If the Gnublin gets a different IP address from the DHCP server after every reboot, the reason is that the ENC28j60 chip has no fixed MAC address and for each load the driver outputs a different address. To be able to bypass, you can assign a static MAC address. For this in File /etc/network/interfaces

nano /etc/network/interfaces

add the following line:

hwaddress ether MAC-ADRESSE

As a MAC address can for example Choose the that has got the LAN module when loading the driver. You can see it here:

ifconfig


eth0      Link encap:Ethernet  HWaddr ba:07:1b:0c:64:0e
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