I’m into computer security a little bit and always striving to learn more. I’m also a firm believer in Open Source software. In Proprietary software you don’t know really know what’s going on. Case in point: Alexa, Siri, Hey Google. They say it isn’t spying on you but you know that it is.
With Open Source software you can view the code and see if any hanky panky is going on.
There are a lot of Open Source Operating Systems such a Linux. But here’s the catch. You run your Open Source OS which gets launched by a firmware (BIOS – Built In Operating System) which is PROPRIETARY!. Also it can prevent you from installing a 3rd party device such as a battery, or charging brick. Major exploits such as HeartBleed (remember that scare a few years ago) live and breathe in the firmware. You can slick the OS, change the hard drive all you want but you are still compromised AND YOU DON’T EVEN KNOW IT.
Let’s lay out a scenario.
I just bought an RSPDuo from SDRPlay and I wanted to see if I could hook it up so I could access it from the network just like I do my Airspy HF+ on SpyServer.
So you dig around on Google and you find out that sure enough you can however it wasn’t as easy as it appeared. Believe me, it never is. I am running my RSPDuo from an Ubuntu 18.04 laptop. In SDRPlay’s defense they have a Raspberry Pi image on their downloads page and this stuff may already be configured. I won’t swear to that though. Laptops have a hell of a lot more OOMPH than a Raspberry Pi though and I just like messing around in Linux.
Lets get started:
OP25 is my FAVORITE police scanner program. I track two trunked radio systems with ONE software defined radio. My Uniden Police Scanner that does that costs $800. This way costs about $30.
Anyway, I’m reading through some OP25 stuff today and I found out it has a web interface. SAY WHAT? Looks like this.
So sometimes a really good technology just never really takes off. A USB TV Tuner is just one such technology.
It should have taken off. Just about everyone who has a laptop should have one of these. I have three.
So what would you use it for? In my case I live in a Hurricane zone and in fact got blasted by Hurricane Florence last year and had no power for several days. (Actually I had power because I have a full house generator). Anyway, due to a concern for the amount of fuel I had on hand I shut down at times and THIS is how I got my news during those times.
Did you ever stop to think about all those radio waves flying around us all the time? Of course you didn’t. That’s why you have me!
Ok I’ve been on a roll playing with OP25 and Raspberry Pi and one thing I can tell you is that the onboard audio from the bcm2835 chip is somewhat inadequate. Oh, it works but you’re going to need a powered speaker or really efficient headphones, and even then it is a bit light.
What to do?
Add a USB Digital to Analog converter (DAC). Depicted here is a HiFiMeDIY USB DAC. This is a tad bit expensive for this project but I have like 4 of these things laying around the house. They are ridiculously good. If you like music slap one of these bad boys on your laptop in the hotel room and the quality of your music will improve ten fold.
That’s not what we’re doing here though.
There are a LOT of USB DAC’s out there and some cost just a few dollars. HiFiMeDIY makes some cheaper ones as well that are way more than enough for improving your OP25 sound.
The Phat DAC costs $15 but you’ll have to solder header pins on yourself. That may be the cheapest, and best route. It has the form factor for the Raspberry Pi Zero but it works on all the Pi’s.
In my last part I set the Pi up to stream to Broadcastify. In this one we are just going to pump audio out through the headphone jack.
I’m doing this with an old generic black RTL-SDR and it works and it works fine but it is kind of susceptible to heat and cold and the ppm correction drifts a bit. I really recommend getting a v3 RTL-SDR or a NESDR Smart as they seem more stable. At any rate it doesn’t matter, you’ll just have to deal with the drift if you have any.
My assumption here is that you have Raspbian installed on at least a Pi 3. I haven’t tried it on a lesser Pi but I had it on a Pi 3 B + and then I found a couple Pi 3 B’s laying around and figured I’d reclaim my B+ for another project on another day. OP25 runs fine on the Pi 3.
So I finally figured out OP25 and I have this brand new Raspberry Pi 3 B + laying around doing nothing. In this segment we’ll install OP25 on Raspberry Pi and then take our police scanner feed and send it to the internet on Broadcastify.
As someone pointed out to me yesterday, “There’s an app for that” they are indeed correct. You can get Police Scanner Apps for IOS and Android. Guess where the feeds in those apps comes from? If you said Broadcastify you’d be correct. So if no one is feeding your municipality then there will be no feed in the app. We will be that feed.
So the assumption is that you have a Pi with Raspbian installed and you kind of know how to use it.
OP25 is a program that decodes P25 Phase 1 and Phase 2 digital radio. Some municipal areas are upgrading to P25 Phase 2 so almost gone are the days that you can track them with a police scanner since P25 is a Trunked Radio system and not just a lone frequency to monitor. The only things that do Phase 2 are hardware scanners and hardware radios and OP25 for software radios. Bear in mind Phase 2 could be encrypted and nothing you can do will decode it.
OP25 is HARD. I’m a geek and I messed with it on and off for a year or more and it whipped me more than once. Now that I have it working I find that it is REMARKABLY easy and I’m mad at all the geeks out there who never made a simple tutorial. There are tutorials out there, some good but everybody leaves out the good stuff or the stuff they took for granted.
So, you are a government employee AND a Linux geek. Join the club. It is possible to use your smart card to access DOD CAC Card enabled sites. A must do project for the Linux geek in you.
I’m doing this with an IOGEAR GSR202 and it will work with a lot of other CAC Card readers as well. Also I’m using Ubuntu 18.04
First of all the information is taken from this excellent website. While almost perfect there are a few minor issues that could foul a fella up. I seek to clarify those here.
First lets download the Certs for your browser. They also come from the page I have linked above (MilitaryCAC.com). Download here. Hold tight. We’ll get back to them.