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PiFm For Orange Pi.

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Post time 2015-3-11 13:07:19 | Show all posts |Read mode
Edited by RaveenBouy at 2015-3-14 23:43

So is it Possible to set the Orange pi as a Fm Transmitter ?  Just like the RPI ? you can refer to these sources.

http://www.icrobotics.co.uk/wiki ... o_an_FM_Transmitter
http://www.raspberrypi.org/forums/viewtopic.php?f=29&t=78376
http://hackaday.com/2014/06/15/e ... -an-fm-transmitter/


Has any1 Tried this before? Or can anybody Test this for me? :3

Thank you =3
Quack A Doodle Doo

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 Author| Post time 2015-3-14 23:43:52 | Show all posts
Bumpy bump!
Quack A Doodle Doo

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Post time 2015-3-15 00:45:27 | Show all posts
I would usually toss all my cash to get on developing and experiment on stuff like that.

But currently im trying not too experiment too much as im saving my cash to get my girlfriend across the border. So it would be some time before I could.

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 Author| Post time 2015-3-16 22:54:54 | Show all posts
Awh man, Good luck ^^ and yeah, there's plenty of time ahead us.
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Post time 2015-3-17 04:22:59 | Show all posts
I  suspect this can be done with some software hacking. I could not exactly judge from the description what they are doing but I suspect they toggle the gpio pin  at the right frequencies.
Doesn't seem to be too high quality.
Also in most countries this could be a good way to run into problems with the law (at least in my country it is)
You can also reach me on freenode irc, channel #orangepi username eFfeM

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 Author| Post time 2015-3-17 18:15:41 | Show all posts
Umm i checked at Leemaker forum and umm it seems they're also unable to figure it out with Banana Pro.
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Post time 2015-3-20 04:00:09 | Show all posts
I have downloaded the software and had a quick look.
As I expected the code is toggling the gpio pin at the right speed to create an FM signal
To make sure this is all done at the proper rate the DMA engine is used to keep transferring the data to the gpio port.

It might be feasible on the OPI assuming that:
gpio pins are memory mapped (accessing the gpio pins through the kernel is way too slow)
the gpio circuitry allows toggling the bit with such fast frequencies
the dma controller is fast enough.

If I had to make something like this the first thing I would do is to toggle the gpio pin as fast as I could and measure with an oscilloscope what speed you can achieve.That should probably be at least 200 Mbit/s.
(and no, I am not going to test this as I do not have a scope).
You can also reach me on freenode irc, channel #orangepi username eFfeM

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Post time 2015-3-24 23:47:29 | Show all posts
A colleague of mine mentioned he saw a rasp pi with this FM radio thing.
His understanding was that actually it is not the base carrier you are receiving but the third harmonic or so.
That will allow toggling the port at a lower frequency but at the same time it will create a more powerful output at a lower frequency (which is what the authorities in most countries do not like)
You can also reach me on freenode irc, channel #orangepi username eFfeM

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 Author| Post time 2015-3-25 12:09:30 | Show all posts
Thnx FransM, ugh =/ hope i could get it with running on OPI( just for fun) I've been scanning through Raspi forum to see whether it works with Raspberry Pi2. But many advanced people :C are claiming that it is illegal to try so and blah blah blah....... But a guy replied to my post saying " PiFM uses the DMA hardware of the Pi at a low level. Unless the Orange Pi uses compatible hardware (unlikely) Pi FM will not work. "  
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 Author| Post time 2015-3-25 12:17:15 | Show all posts
Look here FransM : http://www.raspberrypi.org/forum ... ;hilit=pifm#p724932
I can't understand a thing :c
Quack A Doodle Doo
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