interfacing an ADC (LTC1408-12) with PC

You sound really 'basic', why not use soundcard as a 'free' ADC first then proceed to external electronics?

But to answer your question, yes, but then why not use free octave, a Matlab clone?

If you get it running, come back I've a lot of custom functions and script to operate on those data sets.

On a sunny day (Wed, 10 Sep 2014 07:37:06 -0700 (PDT)) it happened Tareq Matar wrote in :

PC -> PC parport? Laptop may not be so easy.

Im basic :) I have already thought of a sound card but it wont solve the issue since i need to connect six microphones to the ADC.

the programming language is not my problem, but i prefer matlab since i have used it before.

How about three sound cards? You can get them for USB.

--

Rick

Creative Labs EMU1212 has 8 channels at 44.1kS/s, enough?

If you own a copy of Matlab and familiar with it, stick with it, it has the power to do what you want.

Curious, what you doing with six mikes?

Look at the Adafruit trinket.

For $7.00 you get three IO pins (+ 2 more paralleled with the USB). You won't be able to control the 3 select lines with the pc but you should be able to cycle through all the channels.

e

44.1ksps is more than enough i only need about 10ksps, Im using elctret mic rophones

i cant connect them to that card unless there are appropriate microphones t o be used with those specifications

The project im working on is basic in theory but its implementation is hard to me since its my first and im not experienced with hardware at all.

I want to do some processing (Generalized cross-correlation with phase tran sform) on those signals gathered by the mics in order to obtain the time de lay between each pair of mics and find the direction of sound arrival in 3D and steer a camera to that direction.

if you want any further explanation i will be glade to provide it.

Dear Mr. Panteltje

If only you were my teacher in high school or college, what a waste!

nce

i

icrophones

to be used with those specifications

rd to me since its my first and im not experienced with hardware at all.

ansform) on those signals gathered by the mics in order to obtain the time delay between each pair of mics and find the direction of sound arrival in

3D and steer a camera to that direction.

You're question was "How do I connect a LTC1408-12 to a PC". My answer was to connect the PC's USB to the trinket and then the trinket to the LTC1408-

12 conv and sclk pins. I assumed you knew how to connect the microphones to the LTC1408-12.

On a sunny day (Wed, 10 Sep 2014 08:44:44 -0700 (PDT)) it happened Tareq Matar wrote in :

Well, could you elaborate on what you mean by that?

since

ce i

as

microphones

es to be used with those specifications

hard to me since its my first and im not experienced with hardware at all.

transform) on those signals gathered by the mics in order to obtain the tim e delay between each pair of mics and find the direction of sound arrival i n 3D and steer a camera to that direction.

s to connect the PC's USB to the trinket and then the trinket to the LTC140

8-12 conv and sclk pins. I assumed you knew how to connect the microphones to the LTC1408-12.

That's the answer i was looking for, and i can connect it to a laptop. Thank you.

e transform) on those signals gathered by the mics in order to obtain the t ime delay between each pair of mics and find the direction of sound arrival in 3D and steer a camera to that direction.

You would need a beefer micro to do that, unless you have a PC/laptop doing nothing else other than sound processings.

was to connect the PC's USB to the trinket and then the trinket to the LTC1

408-12 conv and sclk pins. I assumed you knew how to connect the microphone s to the LTC1408-12.

Or just s single chip PIC with 24 channels of 12 bits analog and USB OTG. The rest is just software (or firmware).

Matar

eq Matar

can use a standalone matlab file to process the data

I meant that as a compliment.

You have posted many times to some of my previous threads and you always gi ve a hint and leave the rest as a "homework". most of my teachers are not l ike that, they teach what they know and thats it.

There is an old saying and i will try to translate without altering its mea ning, "If you are a fisherman and someone asked you for food then you eithe r give him a fish or teach him how to fish, in the first case you will be a sked for a fish every day and in the other you taught him how to survive".

Regards, Tariq

On Wednesday, 10 September 2014 19:09:03 UTC+3, snipped-for-privacy@gmail.com wrote :

ase transform) on those signals gathered by the mics in order to obtain the time delay between each pair of mics and find the direction of sound arriv al in 3D and steer a camera to that direction.

ng nothing else other than sound processings.

r was to connect the PC's USB to the trinket and then the trinket to the LT C1408-12 conv and sclk pins. I assumed you knew how to connect the micropho nes to the LTC1408-12.

The rest is just software (or firmware).

I will consider that option. Thank you.

Is enough, interesting project.

Let's see 1100 fps means the time shift between adjacent mikes to subtend an angle is ...

resolution will be 8kS/s, per your statement. that's a resolution of 1.7 inches of delay. you may need to place your mikes at 'wide' locations, because close up more accurate than if the subject is 15 feet away

Worthwhile to search for 'sonar' 'seek' information.

why six? why not three? well ok, four if you want 360 degrees, but doesn't four adequately pick out the source?

On a sunny day (Wed, 10 Sep 2014 09:22:55 -0700 (PDT)) it happened Tareq Matar wrote in :

The problem (and I am not into giving complements because I do not care), as I am not your teacher, is that (and I asked several times) WE here do not know if you can write the required code, be it for a PC parport, for a USB I/O device, or for any PIC or other micro. You have never answered that question.

We have discussed the hardware FIFO as a solution, assuming you would indeed use that, then you still need to generate a constant local clock, SPI read, so then you need likely a micro, or do it with hardware - complicated - I dunno about that USB interface thing somebody else mentioned, but USB drivers is not 5 minutes work, and you STILL need the constant local clock.

Yes, that is an old saying, but if he keeps asking how do I hold this fishing net over and over again maybe the hopes he will survive _on self caught fish that is_ will gradually diminish.

I would admire if he stepped into the river and started with a small, say very small, fish. Going for sharks ? OK.

Beware of octopuses.

:-)

My statement was based on a research paper i have read before, they used 8ksps the spacing was about 75cm for some mics and 30cm for a mic in the +z direction.

I can send the paper to you. If you want please send an email to me at snipped-for-privacy@gmail.com

transform) on those signals gathered by the mics in order to obtain the t ime delay between each pair of mics and find the direction of sound arrival in 3D and steer a camera to that direction.

an angle is ...

inches of delay. you may need to place your mikes at 'wide' locations, bec ause close up more accurate than if the subject is 15 feet away

And if the target is moving ...

To the OP: You might be able to hunt (search) in low resolution mode, but once you ide ntify the interesting time frame, you probably need higher resolution sampl ings. Assuming that you also have some servo controlling of the camera, yo u have a very tight control loop. Doing it with PC/laptop/USB latency will be very challenging, not to mansion the amount of data/traffic involved. That's why i think you need some local processing hardware.