The 24 hour torrent downloader plus file server !

I have been obsessed with power consumption for a little while and have been considering ways to bring down the same in my home. One of the big power drainers was the downloading of movies via torrents. The PC used to be up all night downloading movies using up a full 140 watts with a super fast quad core processor and a graphics card drawing good amount of power while just idling. So I was looking for ways to prevent this.

The second issue I had was with the sharing of data between the multiple devices at home and having too much redundant data across drives for various purposes. The ideal solution was to have a network drive which allows all the devices to talk to the drive over the network. But NFS drives are prohibitively expensive and come with too many caveats. So I wanted something simple and cheap.

So here is one great solution. I purchased the ASUS WL-500g Premium V2 wireless router for Rs 5.5k and this one device does all that I want and consumes less than 8 of power for all the wonderful work it does. Here is the router :



The hardware chip on this router is a broadcom, which means that you can flash plenty of opensource firmwares onto this and make it into a full fledged linux machine. DD-WRT, Oleg and Tomato were the options for firmware and I choose the Oleg's firmware since it closely resembles the Asus factory firmware and is well extensible. Here is the link for the firmware: http://oleg.wl500g.info/

Next step, install "transmission", a torrent client to this linux box. Install the windows agent onto your PC and bingo, you have a torrent downloader running on the router, controllable from the PC. Here is how the PC applicaiton looks like when it connects to "transmission" running on the Asus router.



Im sure you are wondering where the downloaded file is saved ? Now the beauty is that the Asus router has two USB ports. Connect a USB drive to it and the linux OS on the router shares the whole drive on the network as it was a network file system. Works like a charm !

Part two of the project was to make sure that I get a USB device that itself that does not draw too much power. So I opted for a 1.8" hard disk with a external enclosure that consumes 1 watt of power. Gives me space for 60 gigs of download space and also serves as a swap disk for the linux box.



Just for the sake of curiosity, above is a picture that shows four external USB drives, a Verbatim 3.5" disk, a Transcend 2.5" disk, a Diva 1.8" disk and a regular USB flash disk. The 1.8" disk seems to be the best compromise between pocket size, speed and price.

So folks, project succeeded ! I connect to transmission on the router from my PC, start off a any download (FTP, torrent and HTTP) and switch off the PC. Download happens all night and the electricity meter is hardly running. And I can monitor it using the transmission internal webpage from my mobile phone !!!

Do remember that all this does not change the main job of the router and it still functions as a fantastic wireless router.

And to top it all up, I have connected a 1 terabyte external hard disk to the Asus box. I switch it on when I need to and it gives me a 1TB network disk !

Aah the sweet satisfaction of a job well done...

"Kill A Watt" for 220v !

I have been recently thinking a lot about how to conserve power. Part of this is driven by the ever increasing number of gadgets in the house which are leading to larger and larger electricity bills !

I did a lot on searching on the net to figure out if a device to measure the amount of current being drawn by any device is available on the net. Sure it was, "Kill a watt" is a much used, much loved device to do this exactly. Unfortunately, like most things American, it uses 120v and there is nothing for the 220v side of the world. And one 220v option available for Europe was just ridiculously expensive.

So that set me thinking that this should not be too difficult to build. With the help of a few friends who were good at circuits, I finally built it for just Rs 750 ($15).

Here is the circuit diagram of the same. Remember that the current has to flow in series through the multimeter. The current has to pass through the multimeter and the selected component in series to measure the current flowing through the circuit.



Now for some live photos and DIY steps of how I to made it.

Disclaimer : Remember that we are talking of live current here, so the standard disclaimers apply. If you electrocute yourself or burn down your house, it is all your fault !!! Be careful with the circuits and do not connect anything till you are reasonably confident it is all going to work.

What do you need ? A digital multimeter that can measure current, these are available for Rs 600 in any good electrical shop. Remember that the multimeter's available for Rs 200 cannot measure current. They only work on DC and measure current voltages. (If there is a doubt, check if there is a "A~" option among the options).

This is the one I used:



You also need a ready made switch box, again available in any electrical shop for Rs 50. Make sure you get a 5amps model as I would not be comfortable connecting a 15amps component to the multimeter.

Now, you are ready to connect the multimeter to the switch box. Chop off one end of the multimeter cable so that you can connect it directly to the switch box. Remember to cut the cable from the side which does not connect to the mutimeter (It will be a special molex cable on one end to connect to the multimeter and a sharp pin on the other side. Cut the side with the sharp pins). Current flows from the mains to the box and the multimeter wires are connected in series.

Here is the snap of the same.



Close the box and bring the cables from one side of the box so that no live wires are hanging out. This is how the completed box looks like:



Now connect the multimeter molex cables to the multimeter and leave it there. This is because current will be flowing through the molex ends and you do not want them to touch the ground.

That is it basically. Set the multimeter to the 20amps mode to make sure the fuse does not blow, connect ANY device to the box and plug the box to the mains. Switch on the current and the device and you can start seeing live data on how many amps are being drawn by the device. If you multiply the amps reading with 235, you get the number of watts being drawn by the device. Note that even though India claims to run on 220v, we actually get anywhere between 220v and 240v in the mains. I seem to be getting 235v almost constantly, hence I multiply by 235. You can measure the voltage in your house using the same multimeter at the precise moment you are taking the reading if you want perfect figures, otherwise 235 is a close approximation.

See the picture here of my old 17" TFT monitor monitor connected to the circuit.



The 17" TFT monitor is drawing 0.21 amps, which translates to 50 watts of current being used. Note that my new 22" LCD draws a similar amount of current which shows how electronic components are getting more and more power efficient !!!

That is it folks, connect any 5amps device to the circuit and measure the current being used.

A homemade DIY Kill a watt on 220v for Rs 750 !!!

Please leave comments if you find this post usefull !