Robot Baby

[shas0002]

The problem is that I have six microphones to record simultaneously and transfer that to a PC at a sampling rate of 22-25 KHz. The resolution required is 12-16 bits. The microphones will be used to determine talker location. The system described will be tethered to a Babies head. It tracks talker location. At the same time record complete audio and video.

The application required is similar to video Tele-conferencing systems following talker location. I have seen a similar system in a system called limelight.

The interface from the micro-controller or DSP should be able to transfer approximately 2 Mbit/s, and be a small implementation.

I am looking for system block diagrams of such systems. So I can get an idea of what is required for the hardware, where can I find such information.

It is important!

Mahesh

 

[nbucska]

I think 8 bit would be sufficient -- if you have AGC.
The sampling rate of 8-10KHz should be enough,too.
Don't forget anti-aliasing filter !!!

<nbucska@pcperipherals.com>

 

[shas0002]

I am aware of this, it has already been illustrated that 2 microphones and using 8 bit ADC’s are sufficient (i.e. HC11 Motorola). The problem is not just finding the direction but recording environmental information so as much information required should be recorded. Hence a requirement of 12 bits to 16 bit range. The reason environmental sound plus the talker information is required, is that learning is a combination of what the environment, is as well as the interaction. This is how babies learn.

What does an anitaliasing filter do, I’ll read on it but I would like a sentence on it please!

Thus I have to find the right hardware for this interface problem?

Thank you

Mahesh

 

[nbucska]

Let's suppose you want telephone quality -- up to 3000Hz--
so you use 6KHz sample rate. If there is e.g. a 7 KHz sound,
you multiply it with 6KHz, generating 1 and 13 KHz.
(check sin(A)* sin(B) !!)

The 13 KHz is outside of the bandwidt but the 1KHz is right
in the middle -- so you must filter out anything >>3KHz...


<nbucska@pcperipherals.com>