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.
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.
Two days before I got my CPLD (complex programmable logic device). Here are some snap shots of my CPLD XC9536.
The main problem is that there is not much support for programming these CPLD xc9536 using free software. There are tools available for programming this cpld. But all of them are for Windows platform.
But there is a small hope. The xilinx website is giving a software named ISE WebPACK Design Software. It’s linux version us available for download.
I have to start hacking the CPLD soon. I have designed the PCB for the JTAG Parallel Cable programmer using PCB.
I would like to say special thanks to Omkar Kulkarni for helping me a lot. He has written a very good tutorial for programming this xc9536 CPlD. check this link http://elecrom.wordpress.com/2008/03/02/getting-started-with-xilinx-xc9536/
Here are some links that might be useful.
Wanna get some cool training on Free software topics like How to do free software projects, Tutorials to use GIT , RPM Packing ? Then come to the online IRC summer training from Linux User Group of Durgapur (http://dgplug.org)
Entry is free. Just log on to the IRC of DGPLUG
#dgplug on irc.freenode.net
You can find more details on
All these training of this year are done by Shakthi Kannan (mbuf).
Time Table of these training are in the Summer Training page.
Just go through the class logs of the classes conducted last year and find out how effective it is.
Try to come for the IRC chat according to the time table given. I am sure it will help a lot.
Special thanks to dgplug for conducting these kind of online classes.
In a pursuit of fabricating pcb’s, I have won. I had designed pcb’s boards using PCB. But when I tried to fabricate the pcb in my home, I used to fail. the problem was with the Acrobat Reader . When I take the print out on the paper for layout transfer to the board, a size change occurs to the layout. This size change make the layout completely useless. Actually it was the wrong option selected in Acrobat Reader that made the size change.Now it is OK.
This is development board designed by me for the ATmega8 microcontroller. It is a miniature ARDUINO. You can burn your bootloader and then use with Arduino IDE or you can simply upload your hex file using DAPA programmer circuit. If anyone needs its schematic file please post an comment or I will soon upload it when I am free.
Anyway this is an open hardware project. I will try to upload the details soon. If you are in a hurry, please comment so that I can upload the details fast.
Here is the PCB layout files http://jeffrey.co.in/files/mini-AVR.pcb
These are the two snap shots of my board
PCB is one of the free softwares for designing PCB‘s. But one of the major disadvantage is that, it lacks documentation. Here is a tutorial by DJ Delorie. This tutorial explains about designing a PCB using ordinary and SMD components. But still some parts are under construction. You can read the tutorial from this link