Two Independent 1090 Mhz ADS-B Receivers on One Pi (No UAT 978)

FlightAware ADS-B Flight Tracking
128

Hello everyone,

I have been searching the Internet for a long time for a solution like this. Has this project been further developed @abcd567 ? The current Raspberry OS version is Bockworm and this in x64, which almost all feeder services now support. I think it’s a very cool thing, I’m facing the same problem with two different ADS-B antennas. I’m always amazed at how backward I am at not being able to do such projects myself, but maybe it’s also because there are only 24 hours in a day.

Greetings Stephan

129

i’d imagine this solution still works just fine.

As an alternative, just use 2 RPis? Makes it quite a bit simpler.

2 Likes
130

It’s a question of money. My budget for gambling that my wife gives me is small less shoes, she doesn’t want to buy. The usual problem :wink: But Black Friday is coming up soon, let’s see what’s on offer.

131

I run two Pi’s at the house. One is the main dude, best/highest antenna, Low Noise Amplifier, good cable, Airspy Receiver, Pi4, hardwired to the router. The other one is my test system to play with and experiment. It too has a good antenna in a first floor window, Blue Flightaware receiver, Pi3b. It runs Piaware and a nifty little DNS tool named PiHole to block the advertising web pages from messing with our internet experience. Having a test system opens the possibilities and lets you experiment without messing with a perfectly good system doing what it does best.

Have fun out there, this is a hobby and hobbies are important too, just like her shoes. Making your systems better and learning new things is never wrong. Best wishes!
Gene

2 Likes
132

Yes, the automated installation script at my Github site (linked below) installs 2-receivers successfully on both 32-bit and 64-bit RaspberryPi OS Bookworm. Please follow upto date instructions on my following Github site:

https://github.com/abcd567a/two-receivers/blob/master/README.md

On above site, automated install scripts for following are also available:

(6.2) Install two instances of Flightradar24 Feeder

(6.3) Install two instances of Planefinder Feeder

 

133

@abcd567 thanks again for the 2-receivers automated script for dump1090-fa and set-gain! Just used both again and they worked great!

134

@abcd567 , what set-gain file can I edit to add the lower gain values to the dropdown list? The current dropdown list stops at 16.6 - I’d like to add 15.7 14.4 12.5 8.7 and 7.7 in case aircraft are only 20 feet away.

135

You expect aircraft which are 20 feet away from your receiver? :flushed:

1 Like
136

 

Edit file gain.php:

sudo nano /usr/local/sbin/gain/gain.php

 

The contents of file gain.php are as follows:

<html>
 <form id="myform" action="gain.php" method="post" />
 <div><font color=#ff0000 face="'Helvetica Neue', Helvetica, Arial, sans-serif">Current Gain: <?php system('cat /usr/local/sbin/gain/currentgain');?> </font></div>
 <select name="gain" id="gain">
   <option value=60>60</option>
   <option value=49.6>49.6</option>
   <option value=48.0>48.0</option>
   <option value=44.5>44.5</option>
   <option value=43.9>43.9</option>
   <option value=43.4>43.4</option>
   <option value=42.1>42.1</option>
   <option value=40.2>40.2</option>
   <option value=38.6>38.6</option>
   <option value=37.2>37.2</option>
   <option value=36.4>36.4</option>
   <option value=33.8>33.8</option>
   <option value=32.8>32.8</option>
   <option value=29.7>29.7</option>
   <option value=28.0>28.0</option>
   <option value=25.4>25.4</option>
   <option value=22.9>22.9</option>
   <option value=20.7>20.7</option>
   <option value=19.7>19.7</option>
   <option value=16.6>16.6</option>
 </select>
 <input type="submit" value="Set Gain" style="color:#ffffff;background-color:#00A0E2;border-color:#00B0F0;" />
 </form>
</html>

<?php
function setgain(){
$gain="{$_POST['gain']}";
system("echo $gain > /usr/local/sbin/gain/newgain");
sleep(5);
header("Refresh:0");
}

if ("{$_POST['gain']}"){
setgain();
}

?>

 

1 Like
137

Yep, the box is on an airplane hangar.

1 Like
138

@abcd567 , I ran the set-gain button script for ip/skyaware/ and ip/skyaware2/ but the 2nd one shows the gain value for the first tuner. What tweaks do I need to make to see the 2nd tuner values on ip/skyaware2/ ?

139

If you use both the new scripts (i.e. new 2-receivers AND new set-gain) as described in following post, then you should not face this issue:

 

140

Thanks! I ran the old 2-recvr script 6 months ago and ran the old set-gain script earlier today. Do I need to now run both new scripts?

141

Yes, because the new one’s have been custom-made to match each other.

I am not sure if running these new scripts on pi which already has standard install will work OK. You may try. If it fails, then re-image microSD card with Raspberry Pi OS, and first run new 2-rciver script, and next run new set-gain script.

142

The Pi has other stuff installed so re-image isn’t an option. I’ll just live with manual gain adjusts for the 2nd tuner and then use your two new scripts for my next build later this month.

Thanks again for the nice scripts!

143

@abcd567 I noticed when an aircraft starts to taxi for takeoff that the /run/dump1090-fa2/aircraft.json file doesn’t show lat & lon for the aircraft but the /run/dump1090-fa/aircraft.json file does. Once the aircraft is airborne and alt_baro shows a number instead of “ground”, the lat & lon appear. Any ideas how to get lat & lon to display with dump1090-fa2 when the aircraft first starts to taxi? Again, dump1090-fa does show lat & lon during that initial taxi but dump1090-fa2 does not. I’ve tested with both gains around 20.

Example …

dump1090-fa2

{“hex”:“a1f61e”,“flight”:"N2251Q ",“alt_baro”:“ground”,“gs”:15.5,“true_heading”:303.8,“squawk”:“1200”,“emergency”:“none”,“category”:“A1”,“version”:2,“nac_p”:10,“nac_v”:2,“sil”:3,“sil_type”:“perhour”,“sda”:2,“mlat”:,“tisb”:,“messages”:543,“seen”:0.2,“rssi”:-11.9},

dump1090-fa

{“hex”:“a1f61e”,“flight”:"N2251Q ",“alt_baro”:“ground”,“gs”:2.2,“true_heading”:53.4,“squawk”:“1200”,“emergency”:“none”,“category”:“A1”,“lat”:27.814442,“lon”:-97.092919,“nic”:9,“rc”:75,“seen_pos”:0.1,“version”:2,“nac_p”:10,“nac_v”:2,“sil”:3,“sil_type”:“perhour”,“sda”:2,“mlat”:,“tisb”:,“messages”:540,“seen”:0.1,“rssi”:-12.2},

When an aircraft lands, both tuners are outputting lat & lon. The problem is only when an aircraft starts on the ground. I’ve noticed when I run view1090-fa that there’s an option to enable ground lat & lon. Is there a similar config option for dump1090-fa2? Maybe it’s enabled for dump1090-fa but not for dump1090-fa2.

144

If the two dongles are fed from two different antennas, this difference may be caused by differences in characteristics and locations of these two antennas and their coax.

To test, swap coax of antennas at connectors of the two dongles, and see if behavior reverses.

145

both dongles use the same antenna. The box is +400 miles away. On the dump1090-fa2 dongle, as soon as the alt_baro field changes from “ground” to 100, 200, 300, etc the lat & lon show up.

146

ground position decoding needs a reference location.

2 Likes
147

my /etc/default/dump1090-fa and /etc/default/dump1090-fa2 have no values for RECEIVER_LAT and RECEIVER_LON. I’ll populate both and see what happens.