[HN Gopher] Building an FM radio from $3 radio chip and an 84MHz...
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Building an FM radio from $3 radio chip and an 84MHz ARM Arduino
Author : 9wzYQbTYsAIc
Score : 41 points
Date : 2022-10-09 07:25 UTC (15 hours ago)
(HTM) web link (hackaday.io)
(TXT) w3m dump (hackaday.io)
| thakoppno wrote:
| People in the US who find this interesting should spend the ~$50
| to get licensed for amateur and buy a UV5R radio.
|
| There is just so much one can do and learn with these cheap
| radios. In many ways, it's the raspberry pi of radio.
| [deleted]
| amelius wrote:
| ... based on the TEA5767 radio module.
|
| So this is more a lesson in how to wire things together than it
| is in how FM radio even works.
| teeray wrote:
| The TEA5767 is a full FM broadcast receiver on a chip. So yeah,
| it's really just how to wire up that chip, connect it to an
| audio amplifier (LM4811), etc. If you want to learn how radios
| work, I'd recommend many of the learning materials out there
| for amateur radio.
| 9wzYQbTYsAIc wrote:
| The enclosure design was interesting - not 3d printed,
| unfortunately, but still looks remarkably clean.
|
| And the choice of user interface was interesting to see - a
| single rotary encoder reminiscent of the days of the iPod.
|
| But, yes, definitely more about how to wire together
| (physically and digitally) the components of a consumer product
| than about how FM radio chips work or how to build your own
| radio from crystals, etc.
| hulitu wrote:
| > Building an FM radio from $3 radio chip and an 84MHz ARM
| Arduino
|
| The article is great. He just forgot to explain how and why (84
| Mhz microcontroller for a FM radio ? ) he did it. /s
| squarefoot wrote:
| That in fact is quite overkill; probably it was what he had at
| hand. That FM chip can be controlled by any uC capable of
| bitbanging i2c, so pretty much every cheap one including small
| ATTiny uCs that cost one tenth of the Arduino Due.
| 9wzYQbTYsAIc wrote:
| Another day, another hack, is the hackaday way.
| zython wrote:
| and for my next trick I'm going to make a slingshot with only two
| parts: a slingshot and a squirrel
| 9wzYQbTYsAIc wrote:
| Hah, neat trick!
|
| https://allanimalsfaq.com/squirrel/how-to-make-a-squirrel-sl...
| anaganisk wrote:
| Didn't RPI have In built capability to do that? I built a cheap
| streaming system, back when bluetooth wasn't so main stream to
| make "piplay" for my stereo in car with Pi2.
| 9wzYQbTYsAIc wrote:
| I'm not sure, it might.
|
| As I recall, some ARM SoC have FM radios in them.
|
| edit: ah, it was the Qualcomm modems that I was recalling
|
| https://www.wired.com/2016/07/phones-fm-chips-radio-smartpho...
| bdowling wrote:
| Sort of. The Raspberry Pi CPU had a configurable clock
| generator that could output up to about 125MHz to a GPIO line.
| Some people figured out that it was possible to rapidly change
| the configuration registers to modulate an audio signal onto a
| carrier frequency in the FM broadcast range. [0] So you could
| make a low power FM transmitter using just a Raspberry Pi and a
| piece of wire.
|
| [0]
| http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspb...
| gregsadetsky wrote:
| Would anyone be able to recommend the most beginner friendly
| "assume (almost) no knowledge" of how to implement an fm radio
| using 1) a dsp "pipeline" 2) analog electronics?
|
| If I wanted to understand every single step of the dsp process
| and what each individual piece of electronics did in "decoding" a
| fm signal, where should I turn to?
|
| Thank you!
| jrockway wrote:
| FM radio receivers were a staple of those electronic kits I
| used to play with as a kid. Here's what a quick Google search
| shows: https://www.electronicsforu.com/electronics-
| projects/simple-...
|
| The difference in complexity between this and something
| commercial are extras like decoding the stereo subcarrier and
| applying the data to the main signal:
| https://en.wikipedia.org/wiki/FM_broadcasting#Stereo_FM
| gregsadetsky wrote:
| Yeah, I also did electronic kits as a kid, and both learned
| how to read a diagram thanks to them, but never understood
| what individual parts did in any circuit.
|
| I "get" I=V/R (I mean not really... I know it exists), but
| how to go from there to understanding what each capacitor is
| doing in the simplest of fm circuits?
|
| Is each component doing the equivalent of non-trivial real-
| time signal processing? How to visualize / think about it?
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(page generated 2022-10-09 23:00 UTC)