Raspberry Pi link

Everything technical about radio can be discussed here, whether it's transmitting or receiving. Guides, charts, diagrams, etc. are all welcome.
Post Reply
SW_UK_UGR
who u callin ne guy bruv
who u callin ne guy bruv
Posts: 10
Joined: Fri Jan 27, 2017 12:39 am

Raspberry Pi link

Post by SW_UK_UGR » Tue Jan 15, 2019 4:36 pm

Hi, not looking to lose anything more expensive than I need to if my transmitter gets discovered..

Ive been looking into using a Raspberry Pi 3 with an updated audio card for picking up the studio link at the tx site and have seen some posts about people on here using them, but from what ive read they are using them over an internal network. Obviously I want to have the TX in a different place to the studio, any advice on the following questions would be wicked :smoke

* What would be the best way to pick up the link, im just thinking of using a WiFi dongle and picking up a stream, but i feel there must be better ways to do this.

* What is the best software to use for encoding stereo etc??

There is plenty of info online but it is hard to properly find the right stuff to read, so im interested to ask you guys who may have tried and tested many ideas etc.

Thanks! :tup

alfaeire
big in da game.. trust
big in da game.. trust
Posts: 81
Joined: Tue Aug 11, 2015 11:17 am

Re: Raspberry Pi link

Post by alfaeire » Tue Feb 12, 2019 10:16 am

Howdy.. I don't get on here much.. So apoligies for the late reply.

I use a pi and it works a treat.

Let me explain my setup.

In the studio our audio is fed into a pc which encodes the audio using WME and it gives us an IP address on the network..
https://www.google.com/url?sa=t&source= ... 9966754400

I have 2 ubiquity WiFi panels. One on the network and one with the pi plugged into it.. They have obviously been matched via their software. I picked them up online second hand for cheep.. https://goo.gl/images/fVa4QT

The pi sits on the tx end, I have runeaudio installed on it.. the ubiquity panel plugged into the pi (it has up to 5km line of sight and hundreds of buildings use them so its hard to trace!)http://www.runeaudio.com

Runeaudio has a browser interface you can log into via your network. Then you can set it up to play a stream with the following : "mms://192.168.2.150" just change the numbers to whatever your ip is. It's all pretty simple and low budget.
https://goo.gl/images/bqqe8d

I've added a hifi Berry to the pi to increase the audio quality..
https://www.hifiberry.com/shop/boards/h ... y-dac-pro/

It was a pretty expensive way of doing things when you can just get yourself a hdmi splitter and take the HD audio from the splitterhttps://www.dx.com/p/hdmi-to-vga-adapte ... GKgvxjp2DY


Hope this helps.

alfaeire
big in da game.. trust
big in da game.. trust
Posts: 81
Joined: Tue Aug 11, 2015 11:17 am

Re: Raspberry Pi link

Post by alfaeire » Wed Feb 13, 2019 4:16 pm

*inexpensive

Sent from my ANE-LX1 using Tapatalk


Albert H
proppa neck!
proppa neck!
Posts: 1164
Joined: Tue Apr 05, 2016 1:23 am

Re: Raspberry Pi link

Post by Albert H » Thu Feb 14, 2019 11:33 am

I'll agree that the $5 HDMI splitter is the way to go. At our source end we're running "darkice" - an open-source media streamer - on a Raspberry Pi 3B with an "audio injector" card attached to it. The Pi is in a 1U 19" rack case, along with the audio injector, a balanced to unbalanced audio board, a stereo limiter and PPM bar graph (not VU!). The unit takes stereo audio in through a pair of balanced 600Ω XLR inputs, and outputs an Ethernet stream straight from the Ethernet socket on the Pi. This is plugged into the studio VDSL modem / router and away it goes to the streaming host (one of the big ones in California) and off to the transmitter sites.

I expected a few seconds of latency, but the FM transmitter sites only lag the studio by around 1850ms. This doesn't mean that the DJ can monitor his "live" output, but it's possible to give reasonably accurate time checks! The lag through the streaming hosts varies from 5 seconds to around 11 seconds. I can only presume that the variability is due to routing changes due to 'net congestion.

I'm going to build several more of the 19" cased streamers in the next few months. People seem to like the idea of a dedicated box for the purpose, rather than tying up a whole computer! It also has the advantage that I can include whatever audio processing the client wants - either inside the box, or connected through insert jacks to allow the use of other commercial processors like DBX, Aphex, or even (shudder) Orban! One option we're offering includes a fast feed-forward delay-line limiter that doesn't overshoot and will temper the output of the most over-enthusiastic DJ!

The Raspberry Pi - along with a good power supply and reasonable quality A to D and D to A conversion hardware provides a really cheap and simple approach to "linking" over the 'net. It is possible to run the software on the £12 Raspberry Pi Zero W, which makes for a further saving. If you house it in a plastic box, you can even make use of its wi-fi abilities. One station that I know in the Netherlands have one set up just like this. They also have an output from the Pi that operates a big opto-relay to switch their main rig on and off remotely. They use an open wi-fi point in the building that houses their rig - it's in a cafe downstairs.
"Why is my rig humming?"
"Because it doesn't know the words!"
;)

Post Reply