Linksys WRT310N Router

This mod came about after I purchased a Linksys WRT310N router for a customer. After using the router during testing I noticed that it became quite hot. This was measured by the mildly scientific method of touching the casing with the back of my hand and feeling the heat output.

These things get quite hot. As many other reviews on the net have pointed out. Google search here

These are available to buy in NZ from CBCNZ

I’ve been a fan of Linksys products for a long time, starting way back with the venerable WRT54G, and still wanted to use a Linksys product for the job I was doing. I probably could have gotten away with using 802.11g but I wanted to try the Draft-N 2.0 goodness.

I decided that I would attempt to cool this beast. Like most of my ideas I went into this one half-assed, without a real plan or any idea how I was going to achieve it.

My initial idea involved mounting a 40mm fan inside the top casing. This proved to be impractical.

It seems that I didn’t try hard enough, someone has managed to fit a 40mm fan on the top of the unit and retain it’s sexy curves. Well done airman

Luckily for me I was helped out immensely by my colleague, Richard. He proposed mounting a fan underneath the router and blowing air upwards through it. This new plan then created its own set of issues : how to mount the router above the fan and still provide airflow?

Enter a broken ATX power supply. Testing proved that the 120mm fan still worked, and the metal fan mount / psu casing we felt could be adapted as a mount for the router.

ATX PSU Cover (sans fan)

This seemed to be the best idea but for it to work we would need to drill out the holes on the underside of the casing to provide better airflow. This part proved to be, quite literally, the most boring.

Making the holes bigger

We also decided to run the router for a day and measure the temperate using a probe. This was to establish a baseline for how hot the thing got, and so we could tell if our endeavours had actually worked.

With 3 wireless users hitting it reasonably hard we found that the temperature peaked at 52 degrees Celsius. Although most of the time it sat around 40 degrees.

I also decided to add some extra heat sinks to the board.

Board pre heat sinks

Board with Heatsinky Goodness

Spray painting the fan mount

As the fan mount lacked any kind of style we painted it. This improved things.

Now available in Black

We then mounted the fan and a dust filter.

120mm's of better airflow

"Luke, I am your father."

With its hat back on

All we needed to do now was put the case back together and test.

How cool? This cool

Now it is ready for primetime. The hottest that we have seen it now is 22 degrees Celsius. So it is a significant improvement. Sadly the customer will probably not appreciate all the effort that has gone into modding their router.

Ready for primetime

List of Ingredients :

Thanks to :

Search here for a D-Link DIR-300 online

I’ve managed to install DD-WRT firmware onto my router. After some frustrating false starts.

Now that I’ve successfully done this I thought I’d post this update to cover what I feel are some limitations in the 2 guides I followed. ( BrainSlayer’s flashing.txt, and shadowandy’s mini flashing guide http://www.shadowandy.net/_html/archives/2007/09/mini_flashing_guide_for_dir300.html)

The part that gave me the most frustration was the initial TFTP of the temp bootloader. As I kept getting error messages from the 4 different tftp servers I tried I was convinced that it hadn’t worked. So I never actually moved onto the next step.
Turns out that you can ignore the TFTP errors when you transfer ap61.ram

After this life became easy again, and the guides easily followed.

The other trouble I had was connecting initially to the redboot shell. I was trying to use the built in WinXP telnet, and while I was able to get a connection I could not send a ^C. When I attempted to use putty as my telnet client I was not able to get the timing right to connect within the redboot timeout window.

That is when I went searching for an automated solution. I’ve stolen the following from a forum about Linksys NSLU2′s and modified it a bit.
http://www.nslu2-linux.org/wiki/HowTo/TelnetIntoRedBoot

(This has only been tested by me using XP)

Requires : putty.exe placed somewhere in your path.
Click Start, then Run, in the run box type putty, click OK. Verify that putty actually starts (and without needing you to click OK on the security dialog that appears)
In putty enter the IP of your DIR-300 (192.168.20.81, and the port, 9000) name the session dir300 and click save session. Then close putty.

save the following as a .bat file


echo off
echo Set objShell = WScript.CreateObject("WScript.Shell") > dir300.vbs
echo Set objExecObject = objShell.Exec("cmd /c ping -t -w 1 192.168.20.81") >> dir300.vbs
echo Wscript.Echo "Start DIR300 after first ping timeout..." >> dir300.vbs
echo Do While Not objExecObject.StdOut.AtEndOfStream >> dir300.vbs
echo strText = objExecObject.StdOut.ReadLine() >> dir300.vbs
echo Wscript.Echo strText >> dir300.vbs
echo If Instr(strText, "Reply") > 0 Then >> dir300.vbs
echo Exit Do >> dir300.vbs
echo End If >> dir300.vbs
echo Loop >> dir300.vbs
echo objShell.Run("putty -load dir300") >> dir300.vbs
echo Do Until Success = True >> dir300.vbs
echo Success = objShell.AppActivate("putty") >> dir300.vbs
echo Wscript.Sleep 200 >> dir300.vbs
echo Loop >> dir300.vbs
echo objShell.SendKeys "version" >> dir300.vbs
echo objShell.SendKeys "{ENTER}" >> dir300.vbs
echo Wscript.Echo "Done... You can close this command window." >> dir300.vbs
echo Wscript.Quit >> dir300.vbsCALL CScript dir300.vbs
del dir300.vbs


With the DIR-300 disconnected from the power run your .bat file. When you see the first line of timeouts appear power on your dir-300

The script should do it’s thing and you (hopefully) will be looking at a RedBoot> prompt waiting for you.