Elektronica Stynus

Sweex LB000021 Router hack

I came across a topic on Tweakers about routerhacking. After reading a few pages I came to the conclusion that I could use this for my weather station project. Part of this hack is a serial interface that I can use to send commands to the router. For example I can send data to my site like this:

wget http://elektronicastynus.be/Projecten/weerstation/data.php?pass=***&temperatuur=25


On a new en used side I came across a sweex LB000021 router that was priced cheap, so I bought it.



The inside:


The hardware should be adapted for this hack, you can read what needs to be done below: 


The first step is to ad a 7805 voltage regulator. This makes the 5V for the usb port. For the 100nF capacitors that go with the regulator I used some 0805 smd ones. These I can solder directly to de leads.

The next step is to suck the solder out of the pads of the usb connectors. If you do this later it can be that you accidental remove smd components.

Then you need a 100µF capacitor and mount it on the place of C91.

L11, L12, L14 and L15 are ferrite beads, I did not have them in smd so Ii soldered some bigger ferrites in place. You can also short circuit the pads.

Then you need to solder a few smd resistors.

R120, R117, R129, R130 = 22 Ohm

R116, R115, R127, R128 = 15 KOhm

The next step is to solder the 48Mhz crystal. My crystal was bigger than the provided place. Therefore I strapped it to the back of the ferrites and connected it to the pcb with wires. If you place the crystal on the pcb then you need to short circuit L4. With wires you can just use the pad of L4.

Then the usb ports must be soldered on. Normally vertical ports should be used, but I did not have those so I put some horizontal on and used some wires to connect them with the pcb. To reinforce them I soldered some flat copper on top. I also soldered a 9-p sub-D connector to it for the RS232 interface.

For the RS232 interface I made a small pcb with a MAX232 on it.

C1 = 100nF

C2, C3, C4, C5 = 1µF

IC1 = MAX232

Eagle files

SV2 goes to the 9 pin sub-d connector


SV2 Pin1 > sub-D Pin5

SV2 Pin2 > sub-D Pin2

SV2 Pin3 > sub-D Pin3

SV1 goes to the router pcb on JP2.


Pinout JP2:









3 5




JP2 Pin2 > SV1 Pin1 (3,3V)

JP2 Pin8 > SV1 Pin4 (GnD)

JP2 Pin1 > SV1 Pin2

JP2 Pin7 > SV1 Pin3

The hardware is now ready.


But then I thought the processor got to hot. So I glued a heat sink on it. I also cut a piece of the cover and put some mesh in it. Then I painted the case.


After I adapted the router, it turned out that the wget commando was not in the firmware from Tweakers. But because it is Linux it can be added. "All I have to do" is to search how to ad it.


Thanks to:

Jeroen for the description of the hack

Lindsey for the router

Pascal for the mesh



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