OT - What I've been doing recently

[bloom25]

These last several months I, along with 3 other seniors here at Oregon State University, have been working on a wireless digital audio project.  I've done all the design, and most of the assembly.  (The other guys are doing simulation, documentation, and some assembly.)  I need to have it finished by May 7th, so as you can imagine I haven't really had time to work on much else.  Just a couple hours ago I got the transmitter to talk to the receiver totally isolated from each other and actually heard recognizable audio for the first time.  After that I decided to take a break, and that's why I'm typing this...

It's actually pretty revolutionary if it can be made cheap enough.  Imagine a device similar to a home audio receiver (or actually built into it)  where you connect all your audio devices such as satellite, DVD, CD player, radio, VCR, etc.  This is our transmitter.  It could use a regular remote control to select which input is currently being transmitted.

The receiver section can be built into virtually any audio device, speakers, headphones, etc.  The receiver can select between multiple transmitters (kind of like channels, if more than one transmitter is present).  What makes this device special is that it is sending 16 bit, 48 kHz sampling rate digital stereo audio (slightly better than CD quality).  If I were to build on what I've got, you could place any device with a receiver anywhere within about 100m or so away from the transmitter and get CD quality sound without any wires.  If it were built into a set of headphones, you could walk around anywhere within your house and it would be just like you were plugged into a CD player.  

To be able to send digital audio at this quality level, I need a lot of bandwidth.  (Specifically 6.144 Megabits/second.)  802.11b (11 Mb/s) or better yet 802.11a (54 Mb/s) can handle it.  Unfortunately, I can't afford the development kits for the more common 802.11b chipsets, so at this point I use a sort of turbocharged infrared setup.  That means I only have a range of about 10 feet, but it's a LOT cheaper.  It does serve as a proof of concept though.  I'm sure as the cost of 802.11b chipsets, the same system that is used for wireless computer networks, come down in price I will be able to do it that way economically,  I designed the system to be able to use any method of transmission capable of handling this data rate.  (Our group is currently calling it a HAN - home audio network.)  I think there is a good chance that you might start seeing similar systems to this within the next 5 years or so as the cost of components necessary come down in price and shrink in size and power consumption.  Currently it would cost around $400 for one transmitter and one receiver if I used 802.11b.  (The receiver can drain a 9V battery, if it's driving headphones directly, in about an hour... )  With IR it's *only* cost me about $150.  I wish I could have afforded to use RF, rather than IR, but I don't have that kind of money laying around.

This is what our group choose as a senior project, which I need to complete my Electrical Engineering degree.  I've spent the better part of a year working on this.  As you can imagine, I'm pretty excited to have actually gotten the thing working nearly perfectly about an hour ago.    You really just can't imagine how good it sounds unless you can actually experience it.  It's just like hearing sound out of a CD player, but there are no wires connecting the speakers to the CD player.  I've only got a couple known small bugs left to work out and it will be ready for demonstration.  I think this may have actually been the very first time this has been done with this high of a bit rate, there is certainly nothing directly comparable on the market like this that I am aware of.

_____________________________ _____________________

I know this has nothing to do with AH, but I'm sure many of you know how it feels to have spent months of your time on something to see it finally come to life and actually work.  For me, seeing something I designed and built come to life and work is one of the best feelings in the world.  After working 5 - 6 hours a day for the last 2 weeks straight on this it was such a relief to have it finally working.  (I'm also very happy to know that I will be able to graduate this term... )

[capt. apathy]

sounds cool.
could have really used that last night.
bought a home theater system and am trying to keep all the wires straight for vcr,dvd,tv, pc vi-vo, and cd/mp3 disc player- it's killing me.

so get back to work so i can clear this wire mess from behind my gear:D

[bloom25]

I realize this isn't AH related, but I'm pretty proud of my work.

We showed our project at OSU's annual open house on Tuesday.  It got a LOT of attention from the industry representatives.  Out of 107 graduating seniors, our group got 2nd place.  The dean of the department personally congratulated us later in the night.(First place was a company sponsored group with $500 extra dollars to burn.  We were unsponsored and had to pay for everything ourselves.  They also had the work of several previous years to build upon.  Basically what they did was develop an active braking system for a baja buggy.)

The potential for this project is huge!  I developed my own data protocol, which can currently handle up to 128 simultaneous stereo streams of slightly greater than CD quality digital audio.  The receiver can pick any stream it wants.  (A very minor modification would be to use ASCII text as part of the code and expand to thousands of streams.  This would allow selection by just entering the name of the song or audio source at the receiver.)  As soon as I can afford it, I'm buying an 802.11b chipset development kit.  If I can make it work, and I'm sure I can, it will be revolutionary.  Several people suggested we patent this immediately.  Unfortunately I can't afford this either right now.

Using 802.11b or Bluetooth 2.0 will allow a single digital stereo stream to be sent wirelessly to any receiver (which can be built into speakers or headphones very cheaply).  Unlike all other wireless audio systems out there today, our system does a real time analog to digital conversion on the audio input and transmits a digital, NOT analog, signal.  This signal is recovered at the receiver(s) and a digital to analog conversion is performed and the recovered audio signal runs through an amplifier to speakers or headphones.  This hasn't even been possible in real time until late 2000.  It's only in the last year that any wireless solutions have been available to handle our bandwidth requirements.

If 802.11a or 802.11g drops in price I can even do Wireless Dolby Digital (AC3).

If I use a CAT5 network cable, I can send 25 simultaneous stereo streams to an infinite number of receivers, which can all be daisy chained to a single cable.  That's why we were describing it as a HAN (home audio network).

I realize a lot of you probably don't understand what I'm talking about, but there are two ways I can go with this at this point.  One way is to go with a high speed wireless radio link and send slightly better than CD quality sound to any place within a house wirelessly.  The other way is to use computer networking cable and set the system up to allow 10 to 20 simultaneous audio streams to be selected by any of the receivers connected to the same cable.  If we used a fiber optic cable, that number could easily scale into the tens of thousands.  Imagine being able to select, at any time, between 10000 or more CD quality audio channels.  When you combine this with being able to also send a few of those streams wirelessly you can understand why I'm proud of what I've done.  Another group was working on an automobile communication protocol and thought it would be possible to integrate this into a car's computer system.  

It will be a couple years before 802.11b chipsets drop enough in price to make this economically feasible.  Hopefully I can manage to capitalize on the idea.  All I need to do know is get ahold of an 802.11b chipset...  You never know, maybe in 5 years something like this could be in your home.  (It's in mine today. )

[Animal]

Bloom, if you follow thru on this, you will be a millionare.

dibs on employment opportunities

[funkedup]

Animal email me funkedup@raf303.org

[bloom25]

I just did some more searching on the patent site and found that someone has already patented something quite similar.  There are a few things my system can do that theirs could not.  Not only that, they couldn't have possibly made theirs work when they patented it, as the chips I used were not available until 1.5 years after their patent was issued.  (Look at the patent site for Wireless Digital Speakers to see their patent, two actually.)

My system can handle multiple simultaneous streams.  The main primary difference is that they specify their system as using a 2.4 Ghz chipset.  Even though they don't specify which, I'm considering developing my current Infrared setup, which I know does work.  I had an idea for a very cheap way to do this with IR that may actually be better than RF in some ways.  They also don't consider using a network cable as a possible transmission method, so that's another thing.

I was kind of disappointed when I finally found a patent that was highly related to my project, though there are no products that have ever used what they describe.

[Animal]

Forget about my job offer, you patent thief


So what are you gonna do?
I'd refine the system, try a patent that wont conflict with theirs, then sell it to some audio company.

[BigGun]

Bloom...what you need to find is some venture capital....lots of places down here in bay area....

of coarse for them you need more than just good idea....you need to put together a pretty good business plan.....just a thought though.

sounds like a cool project

[bloom25]

The silly thing is that I know, judging by the chips they list on their patent, sound quality and cost would not be comparible to my system.  They didn't shoot for greater than CD quality and their costs would be significantly higher.

Regardless, I'll probably still finish mine as I intended and expand it to a point beyond what they had planned.  There are still no products that make use of that patent that I can find.

I think I might try a combination wired/IR approach.  That patent certainly does not apply to those two.  It specifically states "digital radio frequency" transmission.

I have some interesting ideas on things that I can do with minimal effort that would be quite interesting.

[qts]

I don't know much about patent law, and less about US patent law, but I do know that here in the UK if you publish something, you can't patent it thereafter.

So, say no more and go patent it.

[AKDejaVu]

Originally posted by bloom25
I was kind of disappointed when I finally found a patent that was highly related to my project, though there are no products that have ever used what they describe.

Bloom25, stop with the patent searches immediately.

File a pattent based on your designs merrits and let a pattent lawyer/researcher find out if it is viable.

The absolute worst thing to do is to search through other patents.  It can be used against you in that you can get ideas from other people's patents.. only on a slight variation.

AKDejaVu

BTW... someone initially patented the sunscreen in a car.  You know.. those fold-out things you put in the window.  Someone else was able to patent an almost exact design with one minor modification... a cutout for the rear-view mirror.

[AKDejaVu]

Originally posted by qts
I don't know much about patent law, and less about US patent law, but I do know that here in the UK if you publish something, you can't patent it thereafter.

In the U.S. it works a tad bit differently.  If you publish it.. someone else can't patent it... unless they could prove conclusively that their patent wasn't derived in any way from your publication.  That is very difficult to do.

AKDejaVu

[capt. apathy]

if you can't get it pattented right now (for whatever reason) then at the very least take the plans you have and have them notorized or something so you can later verify the dates you had your work completed

[AKDejaVu]

BTW Bloom.. we're trying to do the same thing with processors.

AKDejaVu