Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
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Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
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Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#2Some notes about this setup.
1. The radio will kinda suck. You’re probably not doing it wrong.
2. The sanest way to get pifm to play a stream (say from modipy) is a FIFO. gstreamer will be your friend.
3. Music will sound like garbage without a high and low pass filter.
3.1 Volume becomes an issue, you’ll need to amplify quite a bit to match the volume of real radio stations so your ears don’t get blown out if it flips stations.
4. It’s really low power so really really long wire paid dividends to get whole apartment coverage.
5. Tuning will be really finicky since FM kinda “attaches” to a station and you’ll be competing with basically every frequency already taken by the big towers.
If you want to take the next step I have https://www.adafruit.com/product/1958 and am very happy with it.
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#3Some notes about this setup. 1. The radio will kinda suck. You’re probably not doing it wrong. 2. The sanest way to get pifm to play a stream (say from modipy) is a FIFO. gstreamer will be your friend. 3. Music will sound like garbage without a high and low pass filter. 3.1 Volume becomes an issue, you’ll need to amplify quite a bit to match the volume of real radio stations so your ears don’t get blown out if it fli…
Sigh, getting a amateur radio operator license is not difficult, and teaches people such wonderful concepts like avoiding interference with noisy transmitters.
1. If you are using a modulated square-wave without a filter, than the harmonics/overtones will be splattering the local spectrum.
2. Tools like KerberosSDR/KrakenSDR make triangulating illegal broadcasts rather trivial.
3. Keep in mind, some places have a $5k fine and 1 year in jail... if you are illegally broadcasting.
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#4Note that the video is from 2012. The page itself was last updated in 2015.
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#5[deleted]
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#687 comment HN thread in 2013:
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#7One needs to be careful with such home made devices as they may clash with the officially assigned frequencies.
We had in France a similar story where a village was losing 3G/4G connectivity almost every day around 22:00. It seemed that there are interferences with something.
A special car was sent by the national regulation entity, it was trying to triangulate the source.
They found a house where the owner bought a jammer on AliExpress because he wanted his children to sleep and not go on internet. He thought it was only "for the house".
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#8Some notes about this setup. 1. The radio will kinda suck. You’re probably not doing it wrong. 2. The sanest way to get pifm to play a stream (say from modipy) is a FIFO. gstreamer will be your friend. 3. Music will sound like garbage without a high and low pass filter. 3.1 Volume becomes an issue, you’ll need to amplify quite a bit to match the volume of real radio stations so your ears don’t get blown out if it fli…
Sigh, getting a amateur radio operator license is not difficult, and teaches people such wonderful concepts like avoiding interference with noisy transmitters. 1. If you are using a modulated square-wave without a filter, than the harmonics/overtones will be splattering the local spectrum. 2. Tools like KerberosSDR/KrakenSDR make triangulating illegal broadcasts rather trivial. 3. Keep in mind, some places have a $5k…
> Sigh, getting a amateur radio operator license is not difficult,
It is if you are trying to run from someone who's liable to pluck your address out of a public database (like the one the FCC runs) and come after you, possibly with murderous intent. It is if the government persists in misgendering you because hating you is politically fashionable in some circles. I'm not arguing that it's conceptually difficult, but "That Hobby Where The Government Publishes Your Home Address" might be unpopular for reasons beyond the difficulty of understanding the hobby's conceptual level.
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#9One needs to be careful with such home made devices as they may clash with the officially assigned frequencies. We had in France a similar story where a village was losing 3G/4G connectivity almost every day around 22:00. It seemed that there are interferences with something. A special car was sent by the national regulation entity, it was trying to triangulate the source. They found a house where the owner bought a…
[deleted]
Re: Turn Raspberry Pi’s GPIO into an FM Transmitter (2012)
#10One needs to be careful with such home made devices as they may clash with the officially assigned frequencies. We had in France a similar story where a village was losing 3G/4G connectivity almost every day around 22:00. It seemed that there are interferences with something. A special car was sent by the national regulation entity, it was trying to triangulate the source. They found a house where the owner bought a…
A special car
These have a surprisingly long history, e.g.
https://en.wikipedia.org/wiki/Direction_finding#/media/File:...
