It’s hard to tell…what are the two blue things on either side of the case?
The GPS dongles, i ordered something like this
But until they arrive I Frankensteined clasic ones into weatherproof ones.
The GPS dongles are not really needed for normal Pi3+ or Pi4 use.
May be useful if you disassembled one of the blue Flightfeeders sent by FA - those use the GPS to set location (useful in remote places). Those are custom-made Mode-S Beast, AFAIK normal ones don’t have the GPS input:
It’s basically a Radarcape or at least the FPGA reception board is the same … no mystery there.
And yes there is no advantage for rtl-sdr based receivers to have a separate GPS.
Can you please elaborate on the GPS part? Its true one is a dongle an one is FPGA without the GPS module.
I read somewhere Radarcape attaches some sort of GPS information to the messages, i thought gpsd+piaware does the same thing. Am I wrong?
For the timing information to be useful for multilateration, it needs to accurately measure the time of message arrival at the receiver. This essentially means that the receiver hardware itself needs to be doing this time measurement, as is done in the Radarcape/Airsquitter/FlightFeeder.
In the “rtlsdr dongle + gps dongle” case, the GPS time can only be matched up later, on the Pi, after unpredictable delays due to USB and software not designed to provide real-time guarantees. The accuracy of that timestamp is not good enough to be useful for multilateration.
Thanks for that, it makes my life a bit easier not having to attach GPS dongles everywhere.
Maybe there is a way to attach a GPS module to Mode-s Beast, the non-gps module one.
I see some unused/unsoldered pins. Maybe it could be done, just asking…
Time to show you my setup: it is built around the OrangePi Zero (non-LTS, in its 256MB version), and a FA stick.
It is powered through Ethernet, with a flat cable to run between the window and its frame. The proximity of the Ethernet and power doesn’t seem to impair the ADS-B signal integrity, neither does the heat: the tuner’s drift, accoring to SDR-Kalibrate is within 2ppm.
The fan is here to maintain the CPU temperature at acceptable values, even if I know this exact board is able to work under quite high temps - and is said to report falsely high temperatures, too - and is set to start when the CPU reaches 80°C (and stops at 75).
Fan is controlled by the GPIO, through a NPN transistor.
What is totally unnecessary in this application, are the two BME280 environment sensors, barely visible on the pictures, that I use to monitor values inside the case, and outside.
The case is a classical electric box, which is cheap and totally suitable for outdoor use.
FevreBeaver, very nice setup. I am interested in trying an tower mounted setup like your configuration. Currently my Pi and FA Blue Dongle are in my radio shack (in the basement office) connected with 60ft of LMR-400. Works pretty good but wondering if I have a minimal amount of LMR-400 how many more positions I may get. A few questions:
- Make/model of the weatherproof box?
- Make/model of the POE injector units?
- Jumper block in the lower right?
I use a 5ft long RG58, good enough on such low distances. However, if I’ve had a nice setup running fine for some months, I’m struggling with big issues since I’ve put that one into production (and that was yesterday evening).
1/ The box is, as said above, a rather common electric box, that exact one : https://www.castorama.fr/boite-de-derivation-exterieure-avec-10-passe-cables-et-systeme-de-verrouillage-integre-diall-150-x-110-x-70-mm/3663602794158_CAFR.prd
no doubt you’ll be able to source something similar.
2/ The POE splitter is this one https://www.aliexpress.com/item/4000096422051.html?spm=a2g0s.9042318.104.22.168424c4dlF6qZc fed by a PoE switch ;
3/ The jumper block is, or was meant to be an I²C bus connector. Both environment sensors were connected to this jumper block, each with its own address of course, then at some point one of them lost connection, very possibly because of a bad connection or dry joint, and instead of fixing it, I’ve just hooked that sensor on another bus, because this board has 3 I²C interfaces.
That’s unfair! You will “catch” all the airplanes with the 3 dongles
Will you please write a short description of your setup?
Only the left side is ADS-B. The setup on the right is connected to my Airband Antenna. One dongle running rtl_airband for a permanent feed of Edinburgh Tower and Radar. The other dongle runs rtl_tcp for general airband scanning.