Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: Bluetooth instead?

To: [email protected]
Subject: Re: LF: Bluetooth instead?
From: Stefan Schäfer <[email protected]>
Date: Wed, 19 Mar 2014 00:18:37 +0100
Authentication-results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of [email protected]) smtp.mail=[email protected]
Delivered-to: [email protected]
In-reply-to: <[email protected]>
References: <[email protected]> <A75554795BF441479B7AA3B3AE8BA9BF@gnat> <[email protected]> <[email protected]> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
User-agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3
Hi Jacek,

Thanks for the advice.
Well, before starting with linux, i think i would prefer to lay a 2km long cable through the city :-) All my systems are windows based and wok well since my first own PC in 2000 (windows-linux can be a discussion almost as funny as cw-digimodes :-) ).

Apart from this, my motivation is to run a battery fed MF/LF receiver in the forest which sends its data via a 2.4 GHz link to the shack and is there converted into audio frequencies again. So, on the far end, there is no PC and no internet! And it MUST be a low power device, allowing to run several days with a single battery charge, at least 24*7 hours or better 24*14 hours.

I'm starting to think about spending more time to learn how this can be done. Maybe with a high integrated RF module and an ADC as the main special parts. I have to read about it and ask some programmers here...

73, Stefan/DK7FC


Am 18.03.2014 23:42, schrieb Jacek Lipkowski:
Stefan,

Maybe use a linux platform? Like a raspberry pi, or an old HP thinclient (you can get them very cheap from auction sites). Under linux you can connect any sound card that satisfies your requirements for S/N, sampling rate etc (probably the internal sound card would be ok for the simple stuff, but an external usb card would be better).

This can be connected via wifi. The simplest way to stream would be probably to have a pulseaudio server running on the thin client (pulseaudio comes stock with most linux distributions, so probably you wouldn't event have to compile anything from scratch). You can stream using tcp or rtp (and some other protocols too). On the client side you would also need pulseaudio, and the input should appear as a local sound card to most applications. Pulseaudio has been ported to various linux/unix (macos x included)/windows systems, so software choice would not be a problem. You could also stream via the internet (tcp tunneled in ssl or ssh, or rtp via vpn would be my choice), so that you don't need to set up long range wifi links.

This is a bit more complex than using a bluetooth headset, and requires more power, but is still much simpler than building all of the hardware yourself. The thin client can have much more logic than a simple audio server, it can generate spectrograms by itself etc.

This was probably proposed by others, but i didn't see pulseaudio mentioned anywhere.

VY 73

Jacek / SQ5BPF


<Prev in Thread] Current Thread [Next in Thread>