Today is the day we find out if I’m as prepared as I think I am. While it no longer seems to be a direct hit it does seem like we are JUST outside the hurricane force wind zone and will be in the Northeast Quadrant of the storm where the heavy rains are. Some forecasts show 20-40 inches of rain in this area which will cause massive flooding. I fully anticipate our neighborhood will get cut off.
I’m an RTL-SDR geek and in a pinch that means when the NOAA satellites fly by I can download the Automatic Picture Transmission signal (APT) directly from the satellite and receive real time telemetry. That’s pretty cool I think. Here’s one from Sep 12th in the late afternoon.
Hurricane Florence coming! You’ve all seen weather radios and you’ve all seen they generally cost $50 or more. On a good day you can find one for $35 or so.
The goal is to receive NOAA which transmits on the following 7 frequencies. There will be one or two specific to your area. The frequencies below are in MegaHertz (MHz).
So at this point it is safe to say I’m a police scanner junkie. This started with my love of Software Defined Radio (SDR) devices. You get an SDR then you tune to FM stereo, then you track aircraft ADSB, then somewhere along the lines you start listening to anything you can which includes emergency services stuff.
First you just listen to analog police, then you find out there are digital trunked systems. That evolves into using programs such as DSD+ with Unitrunker or another program called SDRTrunk or OP25.
Then you realize that you’re into hardware scanners. I started out with a Uniden SDS100 which is probably the most technologically advanced consumer grade scanner on the market at this moment. It probably unseated the Whistler TRX-1. If you read the forums there is kind of a Ford/Chevy thing going on with Uniden/Whistler. I had to see what all the fuss was about so I got the Whistler TRX-1.
So I bought the Uniden SDS100 hardware scanner, and I love it. But it cost $700, and then I added DMR decoding for $60, and NXDN decoding for $50. So I’m into this in a big way. The SDS100 is POWERFUL. It is not a toy by any stretch of the imagination. It comes with free control software called Sentinel (yeah the download is hard to find on that page). Sentinel is adequate for managing favorites and reading and writing to the scanner and it is all you NEED.
However I stumbled across this hunk of software called Proscan which looked interesting but it also costs $50. Where does the cost with this scanner end? Well, like most programs Proscan has a 30 day trial version so I gave it a shot. After playing with it for like an hour I knew it was worth the cost so I bought it. It does NOT disappoint.
Ok, I’m more and more impressed with my new SDS100 scanner and just learned that it has GPS capability (with an added external module). Heck I was impressed that you could just type in the zip code and pull in all the local services fit to scan.
And that’s all good unless you are MOVING because as you move on down the highway your zip code obviously changes. Also if you have a GPS module then you don’t even have to know what zip code you are in. Win, win.
Trouble is the “official” accessory for the SDS100 GPS module costs another $100 (with shipping) or so on top of the scanner which already costs about $700. In addition to that you need a $20 cable not included. Ouch! So…..$120 for GPS or roughly $40. You decide!
This module was designed by a poster at RadioReference.com named Hit_Factor who came up with a $42 DIY module.
This is what we are going to make. We need:
GPS Receiver – $35
Mini USB Connector – $7.50 for 10
A USB cable with a USB “A” connector on one end. You probably have one laying around somewhere. Doesn’t matter what is on the other end as you’ll chop it off anyway. It needs to be of sufficient wire gauge so it can carry current. Some cables have tiny, tiny 28 ga. wire. That won’t cut it.
I have a Uniden SDS100 scanner however the only software available for programming and firmware and database updates is Windows only. Sigh. I’m a Mac guy. Wineskin to the rescue. Download Wineskin and double click.
I have so many computers doing various police scanner programs such as SDRTrunk and OP25 that I started running out of computers and Raspberry Pi’s. I’m really enjoying listening to the police scanner much like my father did many years ago with his Radio Shack scanner. I decided to reclaim some computers so I went out and bought a Uniden SDS100 Scanner from Bearcat Warehouse. I had some questions regarding shipping and the scanner and the guy on the phone was super helpful and even called me back to let me know when my SDS100 shipped.
First impression is the cost. Youzah! $650 but this thing does all the digital modes however sadly you have to pay for additional modes if you want them. Not sure that impresses me but I think there is a licensing fee involved with DMR or NXDN so if it were added up front the scanner would be more expensive.
Before you can really do anything at all with the scanner it has to have the firmware installed and the USA (or Canada) database updated. You’ll require a Windows only (BOOOOO!) program called Sentinel. Sentinel can be downloaded from a sticky thread in the Uniden Tech Support Forum on RadioReference.com
The latest BETA firmware can be found in a sticky thread there as well. Bear in mind the Sentinel program will install STABLE firmware. BETA firmware is installed differently than STABLE firmware.
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.