computoman

Finally decided to do something with my Raspberry Pi.  Made a desktop to put it the den. Normally I use a composite monitor, but I decided to use a VGA monitor with an HDMI to VGA adapter. Unfortunately the adapter did not support sound, so I had to use the standard analog audio adapter. Well I hooked everything up and everything was working but the sound. Hmmm. The sound worked before. Did a bit of research and found I had to use a utility to change the default sound output. $ sudo raspi-config  You want to choose advanced options, then  The you want to choose the audio option, then And then lastly choose the output device desired. Wow, the sound worked again. By the way I used xrdp to remote into the rpi to make screen capture easier.

Here is a web based interface to control some low voltage lines via the Arduino.  The web interface will let you either singly turn an led on of off. You can also turn all the leds on or off at one time. From there you can interface all kinds of equipment.  The basic circuit for the project is: Or to look at an Arduino board the relevant pins are: Whether is is for a Personal computer or one of many microcontrollers, the interfacing technique is pretty much the same. Here are two links to consider: http://www.instructables.com/id/Ubuntu-and-the-arduino/  http://www.instructables.com/id/External-device-control-ie-coffee-machine/ Now you can remotely turn on for off many devices and a start at home automation. The code: [code] #include <Ethernet.h> #include <SPI.h> //network NB: Pins 10, 11, 12 and 13 are reserved for Ethernet module. byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; byte ip[] = { 192, 168, 1, 200 }; byt...

Here are a few little schematics and stuff I have collected. I will be adding more as we go along. Each of these projects are under ten dollars each. An old computer (that has a soundcard with a microphone input) to use with a free program called Audacity (for an internet radio station you could use shoutcast and icecast also) installed. Yes, we acquired an old computer from a local user group for free. People (obviously Microsoft users) thought It was worthless. Linux makes computer equipment more valuable. $ sudo apt-get install audacity pavucontrol Step 1: Simple Microphone. Microphone: (Any good piezo buzzer should work.) We tried several piezo buzzers and found the larger ones work better. I also plan to try some old speakers also. The real tiny piezo buzzers from old motherboards need a preamp (they are not loud enough and need additional electronics to help them work better). One interesting thing is that you can also use the piezo mi...

Had some old video without audio and had some old audio without video, so I decided to put them together to see what would happen. Feel like I am in an old silent movie theatre playing the piano. Actually that is me playing the guitar from many years ago. Did it in no time at all with ffmpeg.

Using mathematics or what people have used mathematics for can be fun. One such item is a parabola. It can be used for everything from capturing radio waves to sound. There are a zillion formulas for building a parabola. One such formula is y=x^2/(4+b). But then, if you look closely on the net, there are examples you can use without all the math. In one article, I found a small picture of a parabola form that did not seem useful. Then I thought to myself, what if I enlarged the picture, could the picture be more useful? Saving the picture to storage was the first task. Then we loaded the picture into a viewing program. There you could enlarge the picture and save it in the expanded format. So far so good. Then I printed out the picture. Still do not have a parabola yet. Then it was time to get out the scissors and cut between the splines. Easy enough. Now just one last step in that we need to attach the splines together. Cellophane tape makes that easy. If you add foi...