What's the purpose ?Every developer even remotely interested in performance regularly needs multiple physical machines to test the effects of various optimizations. I'm no exception to this, on my desk lie a number of fanless Atom and ARM boards serving as load generators and web servers when I need to validate certain points regarding HAProxy.
The problem is that you don't always have enough network connectivity on the wall. A simple solution consists in buying some external 5-port switches but at some places you then don't have enough power plugs, and having to deal with extra cables and devices at all time for a test once in a while is not always cool.
Additionally when you have to visit customers for some consulting it's commonly problematic not to be able to plug anywhere or directly behind a test machine.
Nowadays there are interesting solutions like this very inexpensive 5 port Gigabit Ethernet switch which I paid less than $13 shipping included. But this one also requires an external power supply.
Very simple solutionOne will note that the description mentions a 5V power supply. Thus it can very likely be powered over USB. I bought one and used a USB cable adapter to verify that it worked fine once connected to USB. And indeed, it did.
Thus I opened it, de-soldered the power plug, replaced it with a micro-USB female connector, and that was all. Now I can carry this device in my computer bag every day and if I need to connect it, I can pick whatever micro-USB cable available and connect it to my PC or any other power source.
It would be nice if such low-power switches would ship with micro-USB by default. They would cost even less to produce, and would not need to be shipped with a power adapter.
The modification steps are shown below :
1) open the device by removing the top cover and extract the PCB :
2) desolder the jack plug :
3) prepare a micro-USB connector. This one comes already soldered on a board, I just had to re-cut the PCB a little bit to adapt it to the format of the original jack plug :
4) solder the micro-USB PCB, place a piece of foam on top of it to plug the hole, and put the top cover back. You're done :
That's something very easy to do, which saves you from having to carry an adapter or even a special cable everywhere. I wish the manufacturer will think about it for future versions.