From 6032d390e790ca22140af39c30b1bb7d1b441dad Mon Sep 17 00:00:00 2001 From: FreeArtMan Date: Wed, 13 Apr 2022 14:01:50 +0100 Subject: Update rtlsdr_usage notes.Typos fixes and some additional notes --- md/writeup/rtlsdr_usage.md | 53 +++++++++++++++++++++++++++++----------------- 1 file changed, 33 insertions(+), 20 deletions(-) (limited to 'md') diff --git a/md/writeup/rtlsdr_usage.md b/md/writeup/rtlsdr_usage.md index a1440ce..b6e0eed 100644 --- a/md/writeup/rtlsdr_usage.md +++ b/md/writeup/rtlsdr_usage.md @@ -6,11 +6,12 @@ keywords:linux,rtlsdr,gqrx By rtlsdr usually call RTL2832U chip based tv-tunners which -can be used for not just recievin DVB-T frequencies but much more +can be used for not just receiving DVB-T frequencies but much more and yes price is ~$10 it mean that anyone can just buy and try -without "loosing" money. +without "loosing" money. None of examples below requires any modifications +or extra hardware to run. -As of 2022 the cheap that commonly available is r820t2. +As of 2022 the version r820t2 that is commonly available. ### Get sources @@ -85,16 +86,21 @@ then adsb data from plains is received. ## Collection of tools -### FM +### rtl_fm, FM modulation -Get some sound trancmited from FM radio stations. +Get some sound transmitted from FM radio stations. +Find local radio station and set frequency choose wide band FM modulation __-M wbfm__ +set SDR sample rate to any supported, but more then 150kHz, for example __-s 200000__. +Resample SDR output to audio frequency __-r 48000__. Pipe output to any audio tool +here is example for aplay where sampling rate set to same resampled rate of SDR. +IQ format from rtlsdr is signed 16 bit little-endian __-f S16_LE__. ```bash rtl_fm -f 96.3e6 -M wbfm -s 200000 -r 48000 - | aplay -r 48k -f S16_LE ``` -### Spectrum diagram +### rtl_power, Spectrum diagram Scan spectrum to find some activities on different frequencies. Good link with all description is http://kmkeen.com/rtl-power/ . @@ -107,13 +113,13 @@ and then draw image : heatmap.py fm_stations.csv fm_stations.png ``` -### ADSB +### rtl_adsb, ADS-B ADS-B ( Automatic dependent surveillance broadcast ) in simple words airplane -geoposition, speed, height and flight number broadcasting. You can receive +geo location, speed, height and flight number broadcasting. You can receive this data and see how many plains is around and sometimes flight number. -rtlsdr have default one rtl_adsb programm but it shows only received data, +rtlsdr have default one rtl_adsb program but it shows only received data, without any decoding. Here is dump1090 specifically for rtlsdr and nothing more: @@ -123,7 +129,7 @@ description howto install could be found also here http://www.satsignal.eu/raspberry-pi/dump1090.html -Using in interactive mode with height in metrs: +Using in interactive mode with height in meters: ```bash dump1090 --interactive --metric ``` @@ -137,15 +143,16 @@ Output: ``` -### AFSK1200 +### GQRX, FSK1200 -Gqrx is graphical SDR software where you can travel across frequencies -and in real time search for some transmission. +Gqrx is graphical SDR software where you can scan across frequencies +and demodulate and listen FM broadcasts and HAM bands frequencies. +Easy way how to explore the available frequency range http://gqrx.dk/ It have built-in AFSK1200 demodulator or in simple words ham radio packets. -And you could try to see what people sending in tex around the world. +And you could try to see what people sending in text around the world. ### Multimon-ng @@ -160,32 +167,38 @@ Here is few waterfalls for rtlsdr https://github.com/roger-/pyrtlsdr -It have demo waterfall and aslo thats is python bindings to libsdr that +It have demo waterfall and also thats is python bindings to libsdr that could used for fast prototyping ### rtl-entropy https://github.com/EliasOenal/multimon-ng -Project that make rtlsdr as entropy source, uses FIPS 140-2 standart to -verify that data is random enought to pass test. +Project that make rtlsdr as entropy source, uses FIPS 140-2 standard to +verify that data is random enough to pass test. ### rtl_433 -Generic data receiver. Can use to track remote sensors, weather stations and alot -other devices. +Generic ISM data receiver. Can use to track remote sensors, weather stations and many +other devices. https://github.com/merbanan/rtl_433 +``` +rtl_433 +``` + + ## Projects where rtlsdr used ### WebSDR WebSDR probably best site where you can go and click on some radio receiver and listen what happens in some particular country. WebSDR site contains -about 80 radio recievers around the world that can be accessed trought web +about 80 radio receivers around the world that can be accessed trough web interface. + http://websdr.org/ If you want setup your own radio reliever read FAQ, prepare mail and send mail -- cgit v1.2.3