Remote speakers

Almost all of my music is saved on my computer. So, i have to connect my boxes to my computer. I use a laptop with Wi-Fi connection in my bed and it's uncomfortable every time to plug audio jack. After some googling i found a few solutions. Or maybe one solution with different implementations.

The main idea is to "plug speakers" into my home network. The simplest implementation is to use another computer, which is connected to a router via Ethernet and the speakers are connected to that computer. The main disadvantage is the power consumption. The second is that you have to buy a new computer, which can cost a lot. But the advantage is that you can use it also as an external hard drive(like NAS), so 2 things in one machine. The software: i used VLC player(best solution). You can install VLC on a Windows, Linux or MAC. I tried on first two and it works. You can setup your playlist.You can even add online radio stations in your playlist. VLC configurations:

• open VLC, then select Tools > Preferences. In the bottom left corner of the window, under "Show settings", click "All". Than go to Interface > Main interfaces and check the Web radio button.
• than in main VLC window select view > Add interface > Web. 
• edit file C:/Program Files/VLC/lua/http (for VLC 2.0.1), uncomment the line with your network (in my case it was: 192.168.0.0/16).

Or you can make all of above setting from command line typing :
         "C:\Program Files\VideoLAN\VLC\vlc.exe" --extraintf http --intf wx
This is useful when you want to start-up VLC on Windows start-up. Now open your browser and type  http://192.168.0.186:8080, this will open VLC web interface. very simpe :).

The grate thing here is that you can use your smart phone to control that remote VLC. I tried this on my phone which runs android 2.3.3, and my ipod touch 4g. It works on both devices. You just have to install VLC remote(i also tried VLC iRemote) , and you good to go. 
     
I also tried connecting my computer to a TV(over VGA). You can pause play change the volume remotely.

For low power solution you can use for example Raspberry Pi or Beagle Bone. In case the VLC isn't working on that devices you have to make your own program .

Solar concentrator

Solar tubes from neon tubes

Automatic feeder

There are many types of automatic feeders. The one i like is so called screw feeder. The ideea is explained bellow in the picture :

So we need a screw. It's complicated to make one home, without special tools. After a few days of thinking i came up with this:

This is so called meat grinder, that has screw we need. I will try using the whole meat grinder, without some parts. Let's disassemble our meat grinder.

I will use only parts 3, 4, 6 and 7. I will use plate (number 6) with big halls, and not the one in the above picture. I found this one:

It has big halls, so the food can come out easily. It is not enough to use simple motor, because it has to much rpm's. We need a motor with some gears, so called gear motor. We can use something like this:

This gear motor has around 120-180 rpm's.

Serial port in C for Linux

http://www.easysw.com/~mike/serial/serial.html#listing1