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Is something like an AM radio signal decoding relatively easy to understand? What about FM? And NTSC?
Is the python code clear-ish? Complicated? Full of math I’m not appreciating?
Thanks!
Ok… it’s not exactly trivial: https://pysdr.org/content/rds.html#fm-demodulation
Years ago I made a couple of SoftRock receivers for the 20m and 40m CW bands and put them on a couple of Raspberry Pis. I got WebSDR to run on it and it's kinda become a thing now. https://n5dux.com/ham/raspberrypi/websdr.php
> Q: My SDR can be tuned from 0 to 30 MHz (or from 25 to 1900 MHz, or whatever). Can I offer all of that tuning range to the users?
> A: No. Such an SDR does not feed the entire 0-30 or 25-1900 MHz spectrum to your computer: that would be way too much data. Instead, a small part (at most a few MHz) are filtered out in external hardware, centered around some frequency that you can tune. With the WebSDR software, users can only tune around within that small part of the spectrum. You (as the operator of the site) choose the centerfrequency
Rydberg antenna range: 0-20Ghz, https://news.ycombinator.com/item?id=28402527 https://en.wikipedia.org/wiki/Rydberg_atom
Bus width:
W3C WebUSB enables USB device access from JS, TypeScript, WebAssembly, and anything that emscripten emcc can compile to WASM (for use with the in-browser WASM runtimes, or the newish docker WASM runtime CLI arg). Emscripten-forge is one way to build WASM WebAssembly from e.g. C, Python.
W3C WebRTC specifies audio/video/message relaying and NAT traversal: https://webrtc.org/getting-started/media-devices
OpenWRT has an rtl-sdr package but not yet a WebSDR package; and an nginx-ssl package, but there's not yet an nginx-rtmp-module package fwics: https://www.google.com/search?q=nginx-rtmp-module+openwrt
OpenWRT wiki > SDR, LoRA / LoRAWAN , Mesh https://openwrt.org/docs/guide-user/advanced/sdr , https://www.google.com/search?q=openwrt+lora
Pipewire may now arguably be the best way to handle audio and video streams with Linux. Pipewire is not yet supported on OpenWRT ? but is probably already supported by DragonOS (Lubuntu 22.10+)?
Pipewire: https://en.wikipedia.org/wiki/PipeWire https://wiki.archlinux.org/title/PipeWire
https://news.ycombinator.com/item?id=30613125 ... Pipewire to WebRTC:
pipewire-screenaudio: https://github.com/IceDBorn/pipewire-screenaudio:
> Extension to passthrough pipewire audio to WebRTC Screenshare
awesome-amateur-radio#sdr https://github.com/mcaserta/awesome-amateur-radio#sdr
The OpenWRT wiki lists a few different weather station apps that can retrieve, record chart, and publish weather data from various weather sensors and also from GPIO or SDR; pywws, weewx
weewx: https://github.com/weewx/weewx
A WebSDR LuCI app would be cool.
LuCI docs > Modules: https://github.com/openwrt/luci/blob/master/docs/Modules.md
SETI + Unistellar => all cool things: https://www.seti.org/unistellar-and-seti-institute-partnersh... https://www.seti.org/unistellar-seti-institute-education
https://www.unistellar.com/citizen-science/ :
> Citizen Astronomer Network: The Unistellar Network is a worldwide community of Citizen Astronomers working in partnership with professional astronomers at the SETI Institute. Members use their Unistellar telescope to collect astronomical data, which is supplied to SETI Institute astronomers who then use it to develop predictions and models
"Synthetic aperture": https://en.wikipedia.org/wiki/Synthetic-aperture_radar
"WebUSB Support for RP2040" that has 2x20 pin (*) GPIO and MicroUSB: https://news.ycombinator.com/item?id=38007967
A radiotelescope attached to a 30 pin Model B could probably also feed WebSDR?
it's still closed source software? previously: https://news.ycombinator.com/item?id=18571139
If you want to have something similar for use at home, you could take a look at http://kiwisdr.com . I have one, but you need to hunt down EMI sources, before you can properly use it.
WebSDR on other hardware is a better alternative-ish.
I’d love to decode some radio signals - just to go through the “motions” and try my hand at it. Is something like an AM radio signal decoding relatively easy to understand? What about FM? And NTSC? Is the python code clear-ish? Complicated? Full of math I’m not appreciating? Thanks! Ok… it’s not exactly trivial: https://pysdr.org/content/rds.html#fm-demodulation
You really should play with audio samples from your system to get a feel for things, before diving into the math. You can also use it with a $30 rtlsdr dongle.
This is a cool project. I bought both a HackRF and an Ettus USRP B210 years ago for playing with. I am yet to actually do anything of interest! Anyone want to share anything cool they’ve done in the SDR world?
Earlier quoted context omitted.
If you want to have something similar for use at home, you could take a look at http://kiwisdr.com . I have one, but you need to hunt down EMI sources, before you can properly use it.
> but you need to hunt down EMI sources, before you can properly use it. Do you have any recommendations for doing this? I have some source that interferes every 11 seconds for a second or so. It causes packet loss with my wifi (2.5 and 5GHz), and makes my bluetooth game controllers really frustrating to use, since input are missed every time it does it. I assume it's in the microwave range. I'm familiar with RF test…
I’d love to decode some radio signals - just to go through the “motions” and try my hand at it. Is something like an AM radio signal decoding relatively easy to understand? What about FM? And NTSC? Is the python code clear-ish? Complicated? Full of math I’m not appreciating? Thanks! Ok… it’s not exactly trivial: https://pysdr.org/content/rds.html#fm-demodulation
Wow! Thanks for posting this.
It’s not trivial, but very meticulously written.
It would definitely classify as a “learn python the hard way” challenge for a math-y learner.
Years ago I made a couple of SoftRock receivers for the 20m and 40m CW bands and put them on a couple of Raspberry Pis. I got WebSDR to run on it and it's kinda become a thing now. https://n5dux.com/ham/raspberrypi/websdr.php
From the WebSDR FAQ: > Q: My SDR can be tuned from 0 to 30 MHz (or from 25 to 1900 MHz, or whatever). Can I offer all of that tuning range to the users? > A: No. Such an SDR does not feed the entire 0-30 or 25-1900 MHz spectrum to your computer: that would be way too much data. Instead, a small part (at most a few MHz) are filtered out in external hardware, centered around some frequency that you can tune. With the W…
Actually the instantaneous bandwidth of a ryberg antenna based receiver is only about ~4 MHz in implementation papers I've read. A good fit for a 2 MHz instantaneous banwidth $20 rtl-sdr dongle. The 0-20 GHz is the tuning range (again).