“Electronic Design and Fabrication with gEDA” is my first article in LINUX For You Magazine.

This is the first time I am forgetting to blog about my article. Actually it was published in last month(NOVEMBER 2009) issue. Please read it if possible.

This article mainly gives a quick introduction about gEDA. I have also given some snaps of my designs.

http://jeffrey.co.in/articles_talks.html

I have seen some web pages defining that current sinking and current sourcing are same. But the truth is that they are different. This is a tutorial about current sinking and current sourcing in Integrated Circuits(IC).

Current Sinking & Current Sourcing Tutorials

More example programs for Octave has been posted in my wiki page. Please vist

More  Octave Examples

If you don’t know about Octave, I have been maintaining a wiki page for Octave. See the link below

http://jeffrey.co.in/wiki/doku.php/experiments_using_octave_for_b-tech_course

This time I am with an AVR USB board. It is an tiny development board for the AT90USB162 chips.  I have actually made this board design for my friend’s main project. The design has been made using gEDA. It’s an complete open hardware project. But still the schematics are missing.

Actually I have started drawing the board layout using pcb directly instead of using gsch2pcb. I will try to upload the schematic of the board soon as possible.

Special thanks to Sreeraj and Pramode Sir. This project was completed 3 months before. But I didn’t have much time for blogging. Sorry for the late post.

Here are some of the reference links

ATMEL AVR USB AT90USB162 MICROCONTROLLER PROTOTYPE DEVELOPMENT BOARD

AVRopendousDIP – avropendous – Open Hardware Development Board for the AT90USB162

**Here is the board layout file.

sree-usb-noicsp.pcb**

Here are some snapshots.

Last day I bought a USB MP3 player board from a local store in Thrissur. This board can read MP3 files from a USB thumb drive and play it for you.

The board circuit diagram is so simple that there are a very few connections. some of the connections are

• IR sensor connection (3 wires – IR data, VCC, GND)
• USB socket connection (4 wires – VCC, D-, D+, GND)
• Power supply 5V (2 wires – VCC, GND)
• Audio Out (3 wires – Left, Right, GND)
• Switch (4 wires – Next, Previous, Play, Mode)

The other main features are an built in FM receiver and also an remote control. The player can read up to 1999 songs. I have not tried any other music formats other than MP3.

The main attraction is its cost. The board cost only 250 Rupees ( 5$).

Here is the connection diagram details.

http://jeffrey.co.in/blog/2010/10/usb-mp3-player-connection-diagram/

Here are some screen shots

Note(Nov 28, 2009): This is not an open hardware project. Please don’t ask for circuit diagram. I actually bought this circuit board from a local store. The connection details are so easy. The board has markings on it for the connections.