Building a $600 P25 Police Scanner for $250!!! (SDR-Pi)
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- Опубліковано 3 лют 2024
- Here is my latest weekend project; a Raspberry Pi 5 with an RTL-SDR dongle running SDRTrunk software. It is configured to listen to the local LAPD channels and runs great! The chip gets a bit hot so I think I need to add a fan.
Great vid mate, well done. Just a reminder folks, this will do trunking but not decrypt secured channels, so for us in Australia, you will not hear the police.
Exactly. Same thing here in Finland and some other European countries using Tetra.
I've heard that there was some sort of vulnerability in Tetra which allows you to decrypt it but I have not tested that personally.
@@taahaseois.8898 Police here use APCO25 Phase 2 encryption so there are no workarounds for that. 🙁
Now this is slick! I may have to do this! Great video!
Thanks!! I just posted a complete step-by-step if you need any help :) Good luck
I’m going to try this one, I have only heard of people getting trunked signals using 2 dongles. This is great news! Thanks!
You can definitely run 2 dongles, I will show that in a future video
Yes please! Mototrbo dmr tier 2!
Very nice. I just received my first pi5 a couple of days ago and was looking for a project. Even though I'm in a rural area, the next county over has a trunked system. This should be perfect, and I only need to buy a new power supply for the pi5. I already have several rtl dongles and a discone antenna.
I have a sdr kit I believe I'm going to try this
Good luck! Feel free to ask me any questions.
You have my undivided attention. I've been contemplating making something like this for a while and your video gets me motivated. I would love to use a smaller display to match the foot print of the Rasp Pi. Is that a touchscreen with USB cable back to the Pi? or does that pop up go away on its own as the software loads right before you hear the dispatcher talking?
How is your pi5 holding up with sdrt? Have you considered ading a second sdr dongle to handle the bandwidth of your metro p25? In my case pi5 was just not enough to stay stable running sdrt with 2x rtlsdr's in sacramento. The cpu remains very close to pegged like yours, and this resulted in way too much dropped traffic. I reverted back to using an old x86 laptop for now.
Hello, Great video. I was wondering however if there are any projects similar to this one that employ an RTOS instead of using a full Debian based os? I imagine that unless the bottleneck is the CPU based decryption, this could allow for a rpi4 to be able to handle the efforts. This is way outside of my technical knowledge but i like to learn so if anyone has ideas i would be happy to brain storm!
hola pregunta este sofware sirve ´para usarlo en una pc con windows 7
How much RAM does this require? I assume you would need the Pi5 with 8gb to run this?
hey what kind of monitor/tablet do u have there?
Lol I was reading the RTL-SDR blog after ordering one to read my meters, and stumbled across this video! Just so happens we have the same keyboard! Great minds think alike I guess
Hello. I have a question about your setup
Can you give us some info on the display unit you have ?
I'm about to upload a video with all the details and links!
@@TopDNG Double that. Can you please provide the LCD specs? Thanks
Check out my other "HOW TO BUILD" video@@asbari7405 , it has a link to the LCD screen in the description
Does the Hackrfone have the capability of decoding p25? Instead of the RTL you have there?
Yes this should work, but I haven't tried it. I do have a HackRF unit so maybe I can try it soon!
Can you also put out a parts list with link, so we can build one also
Yes, I am uploading a new video now that will have all the links in the description
Does this setup require wifi (after the initial setup)? Or can it run in ‘the field’ just off of the radio frequencies? It looks perfect for part of an emergency comms setup.
No WiFi! Just RF :)
@@TopDNG thank you… Awesome set up!
how does it decrypt the digital signals to hear the good stuff.
It only decodes Digital signals that are not Encrypted
Do you have a write up to run it in headless mode?
Hi Charlie, not yet -- I plan to make one soon; this is the page that helped me figure it out -- die-antwort.eu/techblog/2017-12-setup-raspberry-pi-for-kiosk-mode/
It would be nice if you could add Bluetooth, so we could listen to the scanner via wireless headphones.
If you have it on the pi (or any computer), you should be able to since it takes the speaker output to Bluetooth. At least I can't see why it wouldn't work..
Could you give us a hardware list? What are you using for the screen , etc?
Check out my other "HOW TO BUILD" video it's all in the description!
Skip the first 3 and a half minutes to get to the interesting part.
Thanks for watching Manfred
Does this work with both P25 phase 1 and phase 2?
It should, yes. You might need 2 dongles for some phase 2 systems but I am not sure about this. SDRTrunk introduced phase 2 decoding in 2020
@@TopDNG You need the 2nd dongle for the bandwidth. It has nothing to do with phase 2.
What is the model of the RTL-SDR dongle? Is this the chip RTL2832U?
Yes it is
@@TopDNGcan you share the software? I have one RTL-SDR with 2832u but don't work
@@OrangePiVietnam did you install the rtl-sdr package? The software is SDRTrunk github.com/DSheirer/sdrtrunk
@@TopDNG yes, already, but when i run sdrtrunk, the tunner have status error :(
Ohhhhh@@OrangePiVietnam ; yes, this is a strange error that sometimes happens. Please try using a different USB port (are you using the USB3 port or the USB2 port)?
What hdmi monitor is that?
Hi Steven, there is a link to it in my "HOW TO BUILD..." video for this project!
Monitor -- amzn.to/3SpRURy
Trunking with just 1 sdr?
You should have 2 dongles. I guarantee you're missing a lot of calls due to bandwidth limitations. If a selected P25 frequency is more than 2.4 Mhz away from your control channel, you won't be able to pick it up.
I have 2 dongles, but it's not shown or used here. I'm also not sure what you mean; I am under the impression that the LAPD system has one frequency for each channel. To cover the entire system simultaneously you need two dongles because one doesn't have enough bandwidth to receive all the channels spanning from ~484MHz to ~507MHz. However, if you're only interested in a subset of the channels you can just use one dongle; I don't think that there is a control channel that is required because the system is not trunked -- please let me know if I am mistaken though!
@@TopDNG It's not JUST a control channel, if there are 2 calls where the frequencies are far enough apart you'll get "tuner unavailable". Since one of the BIGGEST advantages of SDR-Trunk is the ability to listen to more than one channel at a time, you could end up missing some calls.
HOWEVER if >ALL< the channels available are inside the bandwidth of the dongle you're good. It appears you're listening to a standard digital system (which is why there's no control channel). It's a pretty safe bet that they will be upgrading to trunking sometime in the future since it allows for a larger number of calls to be handled in a limited frequency range. Generally my understanding is that with the SHEER NUMBER of working units they have in use, they may not be in a hurry (financially) to upgrade, but it will happen eventually.
MOST people will have a trunked system to monitor, and 2 dongles is pretty much a MUST have for trunked systems.
@@TopDNG I forgot to ask... Have you tried entering them as DMR instead of P25? I BELIEVE if you have them set under DMR you can use the map feature to see where they are LOCATED at the time of transmission. I may be wrong, we don't have DMR here, so I have no reference, but I THINK they can monitor their cars locations, and wondered if that's how they do it...
Roger that. Rumor has it they will be going encrypted soon... but yes it's a big financial investment.@@mikeh8416
I haven't tried this DMR experiment; I would be shocked if it worked -- seems like a safety risk to broadcast their locations in a way the public can monitor their whereabouts.@@mikeh8416
Way too much hassle not worth it especially to those who are computer illiterate so don't be building anything you're not experienced with
Ever since baofeng drop the UV-5RH.
But I still dig this too.