Login at Kodi Home

giaur · (This post was last modified: 2014-01-07, 14:17 by giaur.)

According to this: http://www.icrobotics.co.uk/wiki/index.p...ransmitter PI has built in FM transmiter. How do you think, is this possible to implement FM transmiting as audio output for xbmc?

Even if FM is not very good quality, I think it wolud be nice feature. How do you think?

**popcornmix** · 2014-01-06, 18:06

Built in transmitter is putting it a bit strongly.
You can waggle gpio lines at specific frequencies, that allows fm audio to be picked up on a nearby radio.

This is unlicensed broadcasting, and is illegal in many counties (like the UK).
It may well interfere with neighbour's radio equipement.

Having said all that, I was surprised how good it sounded.

giaur · 2014-01-06, 18:21

I belive it's not illegal if transmiter power is low (at least in my country). There are transmitters built in smartphones, also there are fm transmitters for use with car fm radio. So why not on pi/xbmc?

**popcornmix** · 2014-01-06, 19:30

(2014-01-06, 18:21)giaur Wrote: I belive it's not illegal if transmiter power is low (at least in my country). There are transmitters built in smartphones, also there are fm transmitters for use with car fm radio. So why not on pi/xbmc?

Because smartphones have been through EMC compliance testing when transmitting FM, and the signal transmitted is carefully filtered and set to an appropriate dB level.

The GPIO hack on the Pi is unfiltered and produces quite a lot of noise on other frequencies.
It's been reported to work over 100m, so I'm guessing the power generated is too high.

giaur · (This post was last modified: 2014-01-07, 14:16 by giaur.)

I understand your point of view, however I'm not sure that you really need to care about this... final result depends from antenna used etc and responsibility is always on final user. There are some libraries developed by pi devs to enable fm transmiting and they don't have any doubt.

It's indeed not clear situation, but I'm only asking for use hardware functionality that is already present, in my opinion every user should verify by himself if he can use it or how to use it wihout breaking the law.

deejayq · 2014-01-08, 11:36

this indeed would be a nice feature, let's say if you have fm receiving headphones, then you could watch a show late at night without disturbing other people.