arduino and bang & olufsen masterlink

Hi Guys,

I’m fairly new at electronics, and wondered if someone could tell me what I would need to interface an arduino with a B&O Masterlink cable?

I have the document describing the masterlink ports:
goo [DOT] gl [SLASH] neGuV

Which says there are the following wires in the socket:

  • 1: Data - (-0.25V ± 0.1V)
  • 2: Data + (-0.25V ± 0.1V)
  • 3: ML sensor
  • 11: - supply voltage (-7 V to -15V, standby +3V to 15V)
  • 12: + supply voltage (-7 V to -15V, standby +3V to 15V)
  • 13: - L (left channel) (1V bal rin 2.2 Mohm, rout 75 ohm)
  • 14: + L (right channel)
  • 15: - R (right channel)
  • 16: + R (right channel)
  • shield: ground
    Data speed 19,200 bits/sec (<- I assume this is baudrate?)

I’m not too bothered about the audio channels (for now), but wanted to send commands over the Data -/+ to control my audio system.

What I want to know is how can I plug the TX RX (and anything else?) into the masterlink cable, to be able to send these commands?

Thanks! The schema isn't a problem as this has been posted a number of times around the web, plus I'm sure B&O would give it to me if I asked nicely (being a customer and all!).

Thanks for the info.. negative voltages are very much over my understanding at the moment, so I'll probably just buy a BeoLink PC2 and hack the USB api by sniffing the traffic from their Music Player!