transmitter coming from a computer

[bornfedslaughter]

Hello. My name is mike, just getting started in Electronics. I want to know if there is any kind of transmitter that can be built, maybe that could plug into a USB port and transmit songs playing in windows media player. I wanna DJ some songs from my computer for a small radius around my home, any distance would be fine. 100 yards or more would be great.

Can this be done? I would think for sure you could strip a USB wire and hook it up to a transmitter...

How would you tell your computer (or the USB drive) to transmit what was playing in WMP?

Any ideas would be helpful, schematics would be amazing, let me know what's on your mind. I want to know if I can broadcast music from my computer. Thanks.

Send me ideas on here, or through email, which ever you prefer. Thanks.

[email protected]

[Hero999]

Yes it's possible but it's not a good idea for a first project because it's much more complicated than you think.

• The output from a USB port is a digital signal, (either on or off, Wikipedia USB for more information), music is analogue signal (a wide range of voltages over a specific rande). A good analogy is a light switch which is digital (the light is either on or offf) and an analogue dimmer switch (the light can vary in brightness between fully on and off). You need a device to convert the digital to an analogue signal, which is what a transmitter needs, look up digital to analogue conversion on Wikipedia.
• You need to write a special program for your PC called a driver to redirect the signal sent to your sound card by the software (WMP or whatever) to the USB port. This is harder still.
  
• There are lots of simple poor quality monophonic transmitter circuits on the Internet, but you want a decent quality stereo transmitter which is much harder to build.
  
• You'll probably want to be able to tune the transmitter from your PC - a digitally controlled transmitter is harder still.
  
• If you want to fit the whole thing in a nice little USB dongle, you'll have to use a high density PCB (printed circuit board) which is very difficult to make yourself and surface mount components, which are very difficult to solder (some can be as small as 1mm. Try opening up a USB flash drive and you'll see what I mean but your project will be even harder you build into such a small space, as it will be more complicated than just a memory controller and a couple of flash memory ICs.
  

In other words, you're talking about making a project I'd recommend for someone on the final year of an electronics degree course.

The easiest option is to use the analogue output from the sound card but then you need a power supply, whether it be a mains adaptor, a battery or another plug which connects to the USB port. Even then, this is not a project for a beginner because you'lve still got to build the transmitter, which isn't easy.

[Silent Jack]

While there are numerous possibilities as far as feasibility, you also have to consider the local laws and regulations.  The FCC regulates what bands can be broadcast on quite strictly and there are stiff penalties for violations.  If you want to DJ and share your music, also consider copyright and terms of use agreements.  If you own the rights to use the material in a performance format, there are numerous options open to you.  Strictly speaking, from the computer alone, there are numerous software packages you can get for free and "broadcast" on a local area network, or stream online.  If you wanted to give the LAN based approach a try to feel things out, I can recommend some free software that will work.