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Topic: Analogue OUT ! (Read 663 times) previous topic - next topic

nela brown

Dec 01, 2006, 12:23 am Last Edit: Dec 01, 2006, 12:27 am by nela_brown Reason: 1
Hi guys,

I got 2 arduino boards and 2 xbee chips and want to connect contact microphones to 'board 1' analogue inputs and then send the signal digitally (wireless) via xbee to 'board 2' and then convert it to analogue signal and send it out to analogue speakers.
Got all the stuff figured out apart from the analogue out ! I saw on arduino website that you can use AD5206 to do the job - but I can not find it anywhere ! is there any d/a converter you could recommend or have any other ideas about how to convert the digital signal back to analogue so I can send it to the speakers?I already got the amplifier and the speakers just need to hook it up together.
HELP  :'(

Nela x

Daniel

Can you tell us more about what your overall project is?

My immmediate thought was why not just send the contact mic audio over one of those plain old devices (they do seem so very old now)... a radio?

A wireless mic would do the trick. that way you don't have to worry about Xbee etc and data transmission. At the receiving end you could do  the A/D and D/A or DSP or whatever processing you wanted.

mechanisma22

What about program it to convert the digital audio signals into PWM waves out of a digital out. It would sound bad but it might work.

nela brown

Hi Daniel,

I wanted to have some mics outside picking up small environmental sounds being attached to various objects, and then send that info wirellesly to various indoor spaces to reconstruct the outdoors environment. I could do it by sending the data from 'outdoor' arduino to 'indoor' arduino then connecting 'indoor arduino' via usb to Max/msp on my Mac and play it from the speakers attached to the computer - but was hoping to bypass the whole computer thingy and be able to use just electronics. So need to translate digital signal into analogue on 'indoor arduino' so I can wire up amplifier and speakers to it. Any ideas ?
nela

Daniel

hi

If it's audio you're after rather than data, then you don't actually need the Arduino's processing ability, as you're just using it for encoding/decoding at either end.

In that case I would just hack a "family communications" radio, or build a few FM radio transmitters...

For a couple of channels, straight radio will be much simpler, more reliable, and have potenitally much better sound quality as you won't need to A/D and D/A convert the audio.

You could try hacking one of those "family radio" communications units, although the audio will be of limited range (about 100hz-3Khz, like a telephone). Do a google search for "family radio service".  

You can also build small, stereo  FM low power transmitters that have full "deviation" (the modulaiton of the radio signal in FM) and give you something like 100hz-15Khz audio. Then, on the inside end you can digitize and MAX/MSP/PD the audio to your heart's content. the only potential downside to a transmitter kit is that you need to follow good RF design practices: shielding, grounds etc, especially if you are sending  three or four channels of audio. Four independent channels (two stereo transmitters) can be done for less than $100.  

Check out these FM transmitters:

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=FM10C

http://www.hobbytron.com/MiniFMTransmitter.html

nela brown

Thanks Daniel,

I had a look at the links you sent me and got all sorts of ideas ...
I might need to rethink the whole thing and figure out what is the best way forward :-/
x

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