For around $30 in parts and a good amount of patience, you can have a completely open source and hackable mp3 player ready to go. It can be modified to accept serial commands, be embedded in an art project, used as the voice of your next smart talking robo-sidekick, or filled with music and used as is. Put in whatever size card you want, up to the theoretical limit of the MMC format! All the source and schematics are here for free as part of the Creative Commons. I have kits available if you don’t feel like scavenging for the parts yourself.
This player features a shuffle mode, basic track navigation, volume control, FAT32 support, fragmented file support, an unlimited number of files on the root directory, and high quality playback. Files at 256Kbps can be played without a hitch. Variable bitrate files are supported with peaks up to 320Kbps.
The World’s Simplest Open Source DIY MP3 player - [Link]
That’s a very compact nixie clock based on PIC16F84A and 74141 driver IC and MPSA92 high voltage transistors.
PIC16F84A Nixie Clock - [Link]
I work a lot with ESD sensitive stuff – ICs, transistors and other devices. And that means – if I don’t wanna kill em all I need to discharge often – which is quite annoying. But I happen to work with a computer, and a standard input device – the mouse. Which gave me a nice idea – use the Ground connection of the mouse to discharge me.
ESD removal mouse – [Link]
This circuitry allows you to control your computer with a simple remote, like the one you already use for your TV-set. It’s very useful when you want to control a DVD or an mp3 player without having to stay at the keyboard. Please note that this circuit is NOT IrDA compatible and it won’t help you to connect to your mobile phone or whatever IrDA device; it’s only good to control your pc with a standard remote control. I use it for VDR and now my pc is a full featured set top box connected to the television, capable to digitally record and replay satellite television, DVDs and every kind of digital content (mp3, divx). There are many softwares you can install to control this ciruit; for Linux you can use Lirc and for Windows you can use either Winlirc, Girder, IR Assistant or uIRC.
How to build a simple but cool IR receiver – [Link]
The microsat movement is alive and well today, and you can even buy a nifty CubeSat Kit, built around the MSP430 chipset. Seems like buying a kit would take a bunch of the fun out of it, but I guess a lot depends on what sort of “fun” you’re after. It also costs $6,000, but it is, after all, a spacecraft. [via]
Microsatellite kits – [Link]
I wanted to build an etching tank since i first saw one in an article on Make Blog. It was fun to make it and it will sure speed-up my PCB making process. The main thing that i wanted to achieve with my etching tank was to keep it thin so it holds up smaller amounts of etchant, it’s better this way because i need to store and work with smaller quantities. My finished tank holds 1,5 L of liquid when full.
PCB etcher with aquarium pump and heater - [Link]
If you’re looking for a build-it-yourself, standalone, USB harddrive based MP3 player, this may be of interest to you. Originally conceived as a replacement for a CD player, this unit sits on the shelf next to your stereo and connects via standard RCA line-out audio connectors.This is an open-source project. Full hardware schematics and software source code are freely available on this site. As long as it’s for non-commercial use in whole or in part, you may use and modify this design to your heart’s content. [via]
Homebuilt MP3 Player - [Link]
The uWatch is an open source RPN and Algebraic scientific calculator watch that you can build yourself. Jones writes: [via]
It only had an 18 key keypad, but I figured that was OK as my old CFX-400 only had 16 + 4 side keys. All the extra functions were performed with a MENU key and two rows of 4 soft function buttons that mapped to the 8 keys directly below the LCD.
uWatch : World’s First DIY Scientific Calculator Watch - [Link]
Martin Paul writes:
The FX120 will need a little help on the bottom end. The goal was to let them go down to about 50 Hz. With the Mathcad worksheets I designed a Mass Loaded – Tapered Quarter Wavelength Tube (ML-TQWT). Afterwards I contacted M.J. King and asked him to have a look at the simulation I had completed. With his feedback “I think you have a design” (I want to thank Mr. King for his kind help and advice) I made some test enclosures out of chipboard. Figure 1 shows the calculated frequency response for the FX120 for the enclosure shown in Figure 2.
Fostex FX120 MLTL Speaker Project - [Link]