SatNOGS: an Open Source Networked Ground Station

Saturday May 3rd, 2014 by Acinonyx


SatNOGS project is a complete platform of an Open Source Networked Ground Station. The scope of the project is to create a full stack of open technologies based on open standards. SatNOGS is a modular and scalable platform designed as a basis of a global network of ground stations. For the first phase of the project we designed, built, coded, documented and successfully tested the hardware and software parts of the platform, that enabled us to real-time track and communicate with satellites.

Posted in OpenWrt, WiFi, Electronics, HAM Radio | No Comments »

Wireless Battle Mesh v5

Friday January 27th, 2012 by Acinonyx

(26th of March – 1st of April 2012, Athens, Greece)

The next ‘Wireless Battle of the Mesh’ will take place from Mon 26th till Sun 1st of April in the center of Athens (close to the Acropolis), Greece. The event aims to bring together people from across the Globe to test the performance of different routing protocols for ad-hoc networks, like Babel, B.A.T.M.A.N., BMX, and OLSR.

If you are a mesh networking enthusiast, community networking activist, or have an interest in mesh networks you have to check this out!

Informations about the event are gathered at:


The (optional) WBMv5 Warmup event takes place in Sarantaporo (rural area in range of the Olympus mountain). The main event  happens at the National Technical University of Athens (NTUA) in the very center of Athens.


Registrations will be available at different hackerspaces (Fusolab, HSBXL, /tmp/lab, metalab, CCC, …) and on the official website for the event at:


The warmup requires a small fee to cover the transportation costs to Sarantaporo. The main event is free of charge. We offer the possibility to reserve a low-cost bed close to the NTUA for you.

Spread the word

Feel free to spread the word by forwarding this message to all people that might be interested in it. Also blogging about the event is more than welcome!


Posted in OpenWrt, WiFi | No Comments »

Exploring Ubiquiti Bullet2

Wednesday June 3rd, 2009 by Acinonyx

Bullet2 is an AP/Bridge build around Atheros AR2316 SOC. Its CPU is based on MIPS 4Kc technology with a clock speed of 180MHz. It also features wireless and 10/100 Ethernet MAC.

Bullet2 Box

The device comes in a simple black box. There aren’t any documents contained in the box e.g. users’ manual. All directions and information are written on the box.


Its size is much bigger than someone would expect. According to manufacturer specs, the casing  is made of UV stabilized plastic and is suitable for outdoor use. Although it seems that all of the casing is made of ABS material, the LED window is covered by some other kind of plastic. This may be a point of weakness for the weather proofing properties of the device.

Bullet2 without cap

The Ethernet port is protected by a plastic screw cap. There is a very thin rubber gasket at the end of the outer thread for waterproofing, but it can easily get ruined if you tighten the cap too much.

Bullet2 Ethernet

Next to the Ethernet port is the reset button. The maximum supply voltage of 24VDC is also indicated. Bullet2 is powered exclusively through POE.

Bullet2 Cap

The entrance of the ethernet cable is protected by a rubber cable gland. There is a cut (see photo) to help the cable pass through the hole. It doesn’t seem to provide reliable waterproofing.

Bullet2 loose nut

Bullet2 PCB is released from the casing by unscrewing the nut behind the N-type connector. This nut is the only way of fastening the PCB to the casing and it features a special gasket which provides good waterproofing

Bullet2 pulled out of casing

Since the nut is unscrewed, the PCB can be removed freely from the other end. The PCB slides in/out onto special cuts on the inside of the casing.

Bullet2 solder side

There are at least two PCB layers. On the soldering side there is the 10/100 Base-TX physical layer transceiver, the Flash memory and the LEDs. KSZ8721B 10/100 Base-TX has on-chip filtering and very low power consumption. M25P32 Flash memory size is 32Mbit (4ΜΒ) and guarantees 100,000 erase/program cycles per sector

Bullet2 component side

On the component side there is the SDRAM, the 10/100 base-T transformer, the voltage regulator and AR2316 SOC. ICS42S16800 SDRAM size is 128Mbit (16MB) with clock speed at 133MHz. The 10/100 base-T transformer is H16125MCG. The voltage regulator is AOZ1210AI with an efficiency up to 95% and input voltage range from 4.5V to 27V.

Bullet2 without shielding

As you open the metal shielding, AR2316 SOC can be accessed. There is a window for the heatsink on the metal shielding to better cool the IC.

Bullet2 AR2317

There is a sticky heatsink on AR2316 SOC to keep it cool

Bullet2 Flash Memory & Ethernet Physical

It looks like the serial pinheader is hand-soldered…

Bullet2 LEDs

LEDs are in plastic cells which guide light to each indicator window on the casing.

MAX3232 Serial Interface

To connect to Bullet2 via serial we need a TTL to RS-232 interface

Bullet2 & RS232 interface

Supply voltage is 3.3V so we need some IC which can operate there e.g. MAX3232. The supply voltage for the interface is provided by Bullet2 itself.

Bullet2 connected to RS232 interface

The length of the cable between Bullet2 and the interface should be as short as possible.

We can access RedBoot bootloader via serial console and do several tasks on Flash memory and SDRAM like e.g. try a custom firmware without flashing it, revive a bricked Bullet2, etc.

Special thanks to goldendragon for offering his brand new Bullet2 for testing!

Posted in WiFi | 12 Comments »

DWL-900AP+/800AP+/810+ firmware checksum calculator

Saturday January 26th, 2008 by Acinonyx

Firmware Modification Instructions

  • Unarj some_firmware.bin (is actually an arj archive)
  • Modify NML.MEM image
  • Arj NML.MEM back to some_firmware.bin
  • Pad zeros to end of some_firmware.bin until it reaches size 0xe0000
  • Copy hardware version string starting at address 0xdffe0
  • Compile dwl_checksum.c:
    • gcc -o dwl_checksum dwl_checksum.c
  • Calculate 32bit checksum:
    • dwl_checksum < some_firmware.bin
  • Copy 32bit checksum (lsbyte to msbyte) at address 0xdfffc




Posted in WiFi | 1 Comment »

GL2422MP modification for controling TX power

Tuesday September 5th, 2006 by Acinonyx

With this modification you will be able to control the power output of any device that uses GL2422MP miniPCI wireless card in a range from -13 to 17dbm on AP mode and -11 to 19dbm on the other modes. Some devices that use Global Sun’s GL2422MP miniPCI is D-link DWL-810+, DWL-800AP+ and DWL-900AP+.

Power output of GL2422MP is control by a TI (TNETW1100B) chipset. The chipset is driving various voltages on MAX2820 transceiver’s pin (TX_GC) which controls the amplitude of the transmited signal. By altering the TI’s Digital to Analog Converter operation range, we can change the range of the output power to fit our needs (see Datasheet MAX2820). In order to do this, we can simply modify the voltage divider connected to TI’s TX Gain Control output pin which converts the output current of the DAC into input voltage for MAX2820. Placing a potentiometer in parallel with the resistor between Vcc supply voltage and Vtx_gc we can control the power output of  GL2422MP without  having to remove any SMD components thus we don’t destroy the device. If we wish to rebuild the device to its original operation we can simply remove the potentiometer and it will work the same way as it did before the modification. Read the rest of this entry »

Posted in WiFi | No Comments »

DWL-900AP+ rev.B Modified firmware

Monday July 3rd, 2006 by Acinonyx


  • Antenna selection remains the same for both RX and TX
  • More TX power control settings (1 – 18dbm)
  • Power control works on all modes
  • Additional channels (12, 13 and 14)
  • Better web interface


Advanced / Performance

Advanced / Performance

Read the rest of this entry »

Posted in WiFi | 3 Comments »

D-link DWL-900AP+ rev.C Hardware Overview

Wednesday January 19th, 2005 by Acinonyx


  • Mainboard
    • GL2422AP-1T1-B0
      • v1.1
      • v1.2
  • PSU
    • AIC1563CN
      • Input voltage: Up to 30V
      • Output voltage: 3.3Vdc
      • Output current
        • Peak: 2A
        • Continuous: 1.5A
  • CPU
    • Conexant CX82100-4X
      • Core: ARM940T (ARM9TDMI)
      • Max Clock Speed: 168MHz
      • Unused peripherals
        • USB1.1
        • 1 x MII ethernet controllers
  • Flash memory
    • M29W800DB
      • Capacity: 8Mbits = 1Mbyte
      • 100,000 write/erase cycles
    • IC42S16400-7T
    • Capacity: 64Mbits = 8Mbytes
    • Max Clock Speed: 133MHz
  • PLD
    • EPM3032A
      • CMOS EEPROM-based
      • Interfaces with a hex inverter (AHC74)
  • miniPCI slot
    • Probably miniPCI v1.0 compliant slot
    • Wireless miniPCI: GL2422MP-MT2
  • Ethernet Physical Transceiver
    • KS8721B
      • Auto-negotiation
      • 100BaseTX/FX
      • 10BaseT
      • Full/Half duplex
  • JTAG connectors
    • 14-pin (Embedded Ice compatible) for ARM9
    • 10-pin for Altera PLD
  • Serial interface
    • not installed

Read the rest of this entry »

Posted in WiFi | 3 Comments »

DWL-900AP+ rev.C Modified firmware

Saturday January 8th, 2005 by Acinonyx


  • Antenna selection remains the same for both RX and TX
  • More TX power control settings (0 – 18dbm)
  • Power control works on all modes
  • Additional channels (12, 13 and 14)
  • Better web interface


Read the rest of this entry »

Posted in WiFi | 7 Comments »

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