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I want to put together a device that allows >= 128kbps audio to be streamed over a wireless (wifi?) mesh network.

I'm a professional software engineer but have 0 experience in hardware, and I need the greatness of your community to help me get a grib on this. I have done extensive independent research into bluetooth / XBee / Zigbee / arduino wifi boards but haven't hit on anything that seems like the right solution and need some expert advice.

To flesh this out: I would like a durable and compact unit that would have a 3.5mm jack output to an external amp / speaker and a power input (preferably 12v so as to allow the use of batteries). Each unit itself should expand the wireless mesh network, with a range of preferably greater than 10 meters. These boxes would not need to have any audio input - just a wireless repeater (transmit and receive) and an audio out (for speaker). I imagine there would be a slightly different "source" box that would take audio IN and wireless out.

I ruled out bluetooth (master/slave relationship) and Zigbee (lacking bandwidth). I really was interested in the miniSwarm Arduino board (more info: http://forum.arduino.cc/index.php?topic=159327.0 ) but they failed to reach their indigogo goal. What is the best option?

EDIT: I was looking at the DigiX, which supports WiFi mesh and has an onboard DAC for audio http://www.kickstarter.com/projects/digistump/digix-the-ultimate-arduino-compatible-board-with-w . Would its 2 channels, 12-bit DAC with 1 mega-sample conversion rate in single channel mode suffice for this? Just looking around at options at this point.

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  • \$\begingroup\$ Also if no good solution exists, I am reading that bluetooth would allow support from one master to multiple slaves, which would be acceptable if nothing better exists. \$\endgroup\$ – woody121 Dec 4 '13 at 16:49
  • \$\begingroup\$ You want to build this from the component level? Or are you trying to find out which set of pre-built modules you need? \$\endgroup\$ – Samuel Dec 4 '13 at 17:00
  • \$\begingroup\$ Preferably pre-build modules, this is already going to be out of my normal comfort zone and dont want to bite off more than I can chew. \$\endgroup\$ – woody121 Dec 4 '13 at 17:11
  • \$\begingroup\$ 128kbps isn't very high quality for music so presumably you are wanting to broadcast voice data? Maybe you are compressing the audio? I'm just being nosey! \$\endgroup\$ – Andy aka Dec 4 '13 at 17:54
  • \$\begingroup\$ I would love 196kps or higher but I am unsure of what options are out there. This is very much in the exploratory stage at this point :-) \$\endgroup\$ – woody121 Dec 4 '13 at 18:49
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How about something like the Raspberry Pi? Apart from running on 5v (not 12v) it looks about right for you.

This thread in the Pi Forum includes discussion on using a Pi as part of a mesh network and some details of adapters that do (and don't) work for the task. The Pi already has a built in 3.5mm mini jack for stereo audio out and 10m between nodes should be achievable in many situations.

Then for software you've got a range of options and can use a normal pc as the source using something like VLC to create audio streams which Pi's can latch onto, have them set up as receivers and push audio to them, or just have the Pi's pull in files from a shared folder.

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  • \$\begingroup\$ Thanks for the input - 1)I am looking at this thread and see lots about turning the Pi into an access point, but is this mesh networking? I am hoping that each box would be able to both transmit and receive. I assume there would need to be some semi hefty software handling this communication, hopefully I would not need to bake it myself? 2) how would the audio stream(rtmp, lets say) from vlc be read by the pi? \$\endgroup\$ – woody121 Dec 4 '13 at 18:48
  • \$\begingroup\$ There are some specific references to mesh networking in that thread as well as the access point stuff, every node on the mesh being an access point too. Sorry I couldn't be any more specific with the link. With the mesh networks you'll notice they're using 300mb N wifi usb devices but they'll be limited to only using half of that because of the need for duplex Tx / Rx at the same time. The protocols and stacks are fairly light and would just need to be loaded in so far as I'm aware. \$\endgroup\$ – James Snell Dec 4 '13 at 20:06
  • \$\begingroup\$ As for playback, VLC is available on the Pi along with a CLI (command line interface) which you'll want to use since you'll want to run the Pi "headless". \$\endgroup\$ – James Snell Dec 4 '13 at 20:07

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