Ubiquiti Ministation is 802.11 AP Development Platform with full Linux SDK support. After few hours of investigation in my opinion this platform is great for large amount of applications. Provided software has many features, for example measuring Point-to-Point connection speed, changing algorithm of medium access or changing ACK time. What is more, hardware radio part parameters are quite good, all of it with Linux develop platform. Additional benefits are size, on board serial port and power supply by Power Over Ethernet.

ubiquity ministation

• Processor: Atheros AR2313 SOC, MIPS 4KC, 180MHz
• Memory: 16MB SDRAM, 4MB Parallel Flash
• Interfaces: Serial, Ethernet(POE), WiFi
• WiFi parameters: TX Power up to 26dBm, RX Sensitivity from -97dBm
• Wifi work modes: Station, StationWDS, AP Bridge, Client
• Antenna: port MMCX, Internal
• Max Power Consumption: 3.5 Watts

Configuring Development Platform

Specification of processor is inaccessible but SoC has Atheros r4600 core known from OpenWRT products. With all of this knowledge we can start developing and build necessary environment. First download and install toolchain. Because toolchain is in .deb file format on Slackware we must convert it to more convenient file type, thus we use alien.

wget http://www.ubnt.com/downloads/sdk/toolchain-mips-ls_0.1-1.deb
alien -t -c toolchain-mips-ls_0.1-1.deb
installpkg toolchain-mips-ls_0.1.tgz

We must modify our PATH environment variable, for example in ~/.profile file and login again.

PATH="$PATH:/opt/toolchain/mips_ls/bin"

To build own system image:

wget http://www.ubnt.com/downloads/mkfwimage-1.2.tar.gz
tar -xvzf mkfwimage-1.2.tar.gz
cd mkfwimage-1.2
make
wget http://www.ubnt.com/downloads/XS-fw/v3.3.2/SDK.UBNT.v3.3.2.4257.tar.bz2
bzip2 -dc SDK.UBNT.v3.3.2.4257.tar.bz2 | tar -xf -
cp mkfwimage-1.2/src/fwsplit SDK.UBNT.v3.3.2.4257/tools/bin/
cp mkfwimage-1.2/src/mkfwimage SDK.UBNT.v3.3.2.4257/tools/bin/
cd SDK.UBNT.v3.3.2.4257
make xs2

Build image can be found in rootfs/XS2.ar2316.v3.3.2.latest. We can simply update firmware on MiniStation using HTTP configuration page or use on board bootloader RedBoot.

Preparing Hardware

Ubiquiti MiniStation Detailed View

Before connecting power supply to MiniStation and Ethernet to your PC you should prepare yourself special Ethernet cable. This should be straight cable but without pins 4,5,7 and 8 connected, this pins are used for Power Over Ethernet. When your PC card isn’t prepared, can be damaged by cable with all connectors.

On the board we have ready to use serial port, and not mounted header for JTAG interface. I’m wondering if JTAG interface works, I didn’t check it. We must remember that signal level are CMOS 3V3 and connecting Rx, Tx signals to other logic should be done in a proper way. Using FTDI232 5V converter we can put in-line 1K resistors on Tx, Rx lines. We connect Rx MiniStation with Tx FTDI232 pin. Pin 1 is marked white drop on the PCB and pin assignments is :

Pin 1,2 3V3
Pin 3 Rx
Pin 7 Tx
Pin 5, 9,10 GND

ser2net can be downloaded from project page http://sourceforge.net/projects/ser2net/

tar -xvzf ser2net-2.5.tar.gz

./configure --host=mips
make
cp ser2net-2.5/ser2net ~/tftpboot

At the end we need to copy compiled server to directory there tftpd server files are kept and accessible for clients.

echo "2001:raw:0:/dev/ttyS0:38400 NONE 1STOPBIT \\
 8DATABITS -XONXOFF LOCAL -RTSCTS" > /var/ser2net.conf
cd /var
tftp -g -r ser2net 192.168.1.2
chmod +x ser2net
./ser2net -u -c ser2net.conf

At this moment we have configured serial port server. We can connect with him using fe telnet:

telnet 192.168.1.20 2001

Configuring 802.11 interface we can connect wireless to serial port. More info about product can be found at http://www.ubnt.com/products/ministation.php. Pricing starts at approximately $160 in single quantities.