RTL-SDR V3 issues activating bias t

Hmm may be not quite. When I reboot, stop 1090 mutability, go into the relevant directory, rtl_biast/src and re issue the ./rtl_biast -b 1 commnad, I get this error “-bash: ./rtl_biast: No such file or directory” ??

The rtl donlges only allow one program to connect to it at a time. If dump1090 is connected to the dongle then you would need to stop dump1090 before you run the rtl_biast program.

The “usb_claim interface error -6” is because the RTL device is used by another program.

To stop dump1090 you can “kill” the program OR use systemd to stop it:

sudo systemctl stop dump1090-fa
or
sudo systemctl stop dump1090-mutability
or
sudo killall dump1090-fa (must have killall installed)

You can restart the program with

sudo systemctl start dump1090-fa

You can see active programs by running

top
OR
ps aux

“./rtl_biast: No such file or directory””
You can use the find command to see where the program is located.

sudo find / -name rtl_biast

The ./ in front of the command ./rtl_biast -b 1means run the command relative to the current directory.
You can also run rtl_biast from the absolute directory found by the find command.

If you run “sudo make install” after making the rtl_biast program it will install the command. You can then run the command with no path such as “rtl_biast”

Would it be possible to have the rtl_niast program and the switch to turn it at the appropriate time included in the next image of piaware released by Flightaware.

I run a standard piaware image on several installation and all the instructions to get, compile and run rtl_biast at the appropriate time in the boot procedure just manage to destroy the working image and I go back to the beginning and start again.

My interest is in RF, antennae, signal, noise, gain and the optimisation of position reports and aircraft. I have no interest in Linux or programming.

I would prefer it added to the Configure page of the My ADS-B page as the neatest option (where gain setting should also be located) but adding it to the piaware-config would be the next best place.

Your consideration would be appreciated.

S.

Changing Piaware Settings Without SSH and Without microSD Card plugged in Desktop

Thanks, but I can’t see how that helps.

I can run SSH and I can plug the microSD card into the computer. It doesn’t help me get the rtl_biast program nor turn it on at the appropriate time.

What am I missing?

S.

In that thread I have suggested facility to set UUID and GAIN etc from Browser on a Desktop/Laptop on Local Network.

Continuing the same philosophy, this facility can also be provided on the “My ADS-B” page, (as suggested by you), which is again a browser interface. Since “My ADS-B” page is accessible from anywhere in the world through internet, it is a much better and more secure option, specially for remotely located sites.

:smiley:

Sorry, I thought you were proffering a solution to my problem where I want to turn on biasT for a V3 dongle.

I agree that much more useful things can be added to the My ADS-B page to make management more readily for those of us who no longer get joy with tinkering in software. (Been there, done that but moved on to bigger and better things and left COBOL and FORTRAN a long time ago).

I would appreciate a definitive list of instructions to create the rtl_biasT program on the piaware image but all the instructions I have found start with running git and it appears that git is not installed on my image.

Hence I keep taking one step forward and two steps back each time I touch it.

I suspect that the answer to my problem will be to wait till after Easter and buy the parts and simply make a 4.5V power injector.

S.

Do this before you start with instructions to create the rtl_biasT program on piaware image.

sudo apt-get update
sudo apt-get install git

And then what?

I got past that bit which was not mentioned in any of the instructions I found.

Nor did I find a requirement to install git-utils or something similar. I only found that when I scrolled back to see if git had installed correctly when it wouldn’t work.

I muddled through and eventually created rtl_biast and I could turn the volts on and off but I could not follow successfully any of the instructions to locate it and start it before dump1090 claimed the device. (I foolishly didn’t keep notes of the instructions that actually worked so I have to start again, again)

Thanks for your interest and I do appreciate the huge input you have to this forum.

Cheers,

S.

Type of PI being used ??

Have you got biast working at some stage and are looking for some switch development??

Before we get too much further can I point to my post above where I asked for rtl_biasT to be added into the piaware image.

I did eventually make rtl_biasT and I did manually test that I could turn the volts on and off. As I had gone down so many dead end paths attempting to follow the many instructions I found, I deleted that image and went back to a virgin image to ensure stability.

In answer to your questions then

  1. I have a Pi 3B

  2. I have a virginal piaware 3.5.3 in and running with the ONLY modification being Wi-Fi SSID and Password.

  3. Without breaking anything, I want to install rtl_biasT and turn it on before anything else claims the receiver.

My suggestion was for Flightaware to add the rtl_biasT functionality to the next image release and provide a method of turning it on in preferably the Configuation page in the My ADS-B page or in the piaware-config file.

I’d also be happy if someone could give a tested set of command to unambiguously setup a virgin piaware image to install the software and set a switch to turn it on first. (and yes, I like to use the words virgin and virginal in this context).

Thanks,

S.

ok. I have had biasT running. I have not developed any switching and have had to do every thing manually. What I have found, is that I need to be in exactly in the directory SRC. I make sure that I have turned off mutability BEFORE I switch on the bias t. Once I have confirmed the 4.5V output, then I re start mutability. So far, I have not had any issues apart from the obvious very manual way of getting this going before mutability is running. I take it you do not need any scripts etc to get bias t working, thats is what I could have provided :slight_smile: Jeff

.
(1) This seems to be a low-priced solution.
The down side is very long delivery, Over 2 months.

.

.

(2) This is another option, but at 5 times the price of (1).
.
https://www.ebay.com/itm/Bias-Tee-Operates-from-10MHz-7000MHz-Bias-tee-Bias-T-DC-HDR-12V-or-USB-pwr/282542069310

.

.
(3) Another option

https://www.ebay.com/itm/PCT-Series-PCTMPI1G-Power-Inserter-for-PCT-CM-Distribution-Amplifiers-or-Preamp/291540280382?hash=item43e127a43e:g:8HkAAMXQbcRQ5w3O

.
.

(4) This is a DIY Bias-T, if anyone is interested in DIY.
Uses a recycled TV Splitter, a 200pF ceramic capacitor, and an axial inductor or self-made coil.

NOTE:
Click on the images in this post to see larger / full size

if your using systemd can you not set the biasT stuff up as a service (run once) and add it to the requirements of mutability service?

That way then mutability tries to start it has to start biasT first. Not 100% sure this will work but it might be worth looking at.

I bought a bias t via ebay last week, should be here on Tuesday I hope. https://www.ebay.com.au/itm/112742416931?ul_noapp=true

Thanks for those suggestions.

I checked one of my local suppliers and they have this.

http://www.radioparts.com.au/product/00760721/vc12pinj-‘f’-line-dc-power-injector-resi-linx

(87 in stock)

My buy price is only $AU2.20 so I will get a couple and crack one open and see how they do it and I can modify it if needed.

Thanks everyone for your suggestions.

S

@SweetPea11
Great find!
At AU$2.2, it is almost free. Good idea to buy a bunch and crack open one to see what is inside.

Whatever the physical configuration, in most bias-ts’, the circuit is basically a capacitor and an inductor, as shown in diagrams below:

Bias-T-Diagram-421x227px

Bias-T-microUSB-432x324px

.

Please click here to see my post dated Sept 17, 2013. Its Photo #2 shows details of a DIY Bias-T which I have made at that time. There are notes added to the photo, explaining what is what.

.
.

We can look into adding the option to piaware-config
OR
We can have the compiled command added to the piaware image. This would then require the user to enter one or two lines to set it up on boot.

The main problem is that liability is an issue. If someone turns on the bias-T and then shorts their RTL-SDR blog dongle or the dongle shorts something on the antenna feed then who is responsible?
I guess warning in multiple places can help a bit.

See the warning on the RTL-SDR blog dongle:
https://www.rtl-sdr.com/rtl-sdr-blog-v-3-dongles-user-guide/
This is a real problem that probably caused a few receivers to stop working.

Yes, please.

I’m NOT/NOT a lawyer, and this is NOT/NOT a legal opinion, but warnings, and making it ‘harder’ to activate accidentally, should take care of the issue.