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Topic: Adruino Intercom System (Read 3551 times) previous topic - next topic

joshchab

Hello, I'm looking to create a wireless intercom system at my house using the Arduino. All of the cheaper intercom systems I've found online have only four lines (I'm looking for around 6), and all of the systems I've found with more lines were very expensive. I'm pretty new to the Arduino and have basic circuit knowledge, but I feel as though this project wouldn't be too bad. The system I was envisioning would be something like this: each intercom would have it's own Arduino connected to a microphone and a speaker. In turn, the Arduinos would be connected to each other wirelessly via XBee shields. Each intercom would also have various buttons to control which intercom to communicate with. I've done a preliminary search through Arduino forums and such, but there doesn't seem to be any info about streaming audio between Arduinos through XBee shields. Does this project seem feasible? Can I stream audio through XBee shields? Thanks.

Grumpy_Mike

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but there doesn't seem to be any info about streaming audio between Arduinos through XBee shields

That has to tell you something.

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Does this project seem feasible?

No

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I stream audio through XBee shields?

They are not very suitable for this.

joshchab

Thanks for your feedback. I kind of figured it couldn't be done from the lack of info on the web  - I just wanted to make sure. Could you perhaps elaborate on why it wouldn't work? Are there any alternatives I could look into?

Grumpy_Mike

It won't work because:-
1) The arduino's A/D is only 10 bits and that is not very good quality
2) The arduino has only an 8 bit D/A through the PWM so that is even worse.
3) There is not much memory space to buffer any sound
4) The Xbee transmits data in packets not continuously so you would have to implement a system of time stamped packets, transfer them into a buffer and feed out the buffer at the sample rate. See 3)
5) The Xbee is a bit slow for this sort of thing. It has a top raw speed of 250K baud which translates to 25K bytes per second. With the handshaking this cuts the speed down even further so you would only get a sample rate in the order of 8K samples per second.

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Are there any alternatives I could look into?

I bought a wireless phone for my land line and that acts as a wireless intercom, so no need to plug it into a land line. It is a Logik and was cheaper the three arduinos and three Xbees with shields.

joshchab

Thanks for your quick and helpful feedback. I'll check into that Logitik system you mentioned.

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