yet another Lang_RX/TX.py error

Forum for discussion about the Langstone Microwave Transceiver that shares some features with the Portsdown. Wiki: https://wiki.microwavers.org.uk/Langstone_Project
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f6itu
Posts: 4
Joined: Sun Jul 18, 2021 6:02 pm

yet another Lang_RX/TX.py error

Post by f6itu » Mon Jul 19, 2021 3:41 pm

Hi
I'm a complete newbie trying to install and use Langstone (alone, without portsdown).
The cpu board is a Raspi4 with the 7' touchscreen
I scrupulously followed the github instructions.

The first run ended with a "Lang_RX.py" error. The USB "white-as-in-the-langstone-wiki" key was not working (even if seen by lsusb and the ./set_sound code)

After changing the device, a "1) hw:CARD=ICUSBAUDIO7D,DEV=0" was immediately recognized. But alas, still the same Lang_RX.py error when booting Langstone.

After a few tries, I realised that stopping and running Langstone via the SSH console made this error disappear and displayed my waterfall. RX is clear and demodulation perfect

In other words, Langstone is running without troubles .... as long as you stop and re-run the code. Technically satisfying but ergonomically boring.

I also discovered that the USB dialog between the raspi and the Adalm-Pluto was very slow. Pluto_Test gave me a

"1000 Calls made in 1601 ms with 0 failures
Pluto throughput measured at 624 calls per second
Typical value on a working system is 1900 calls per second"

I have nothing between the Pi4 and the Pluto board, I changed several times the cable, and the PSU is an original Raspi one.

Does anyone have a vague idea of what the problem is?

With my VY 73'
Marc f6itu

g4eml
Posts: 446
Joined: Thu Apr 26, 2018 9:36 am

Re: yet another Lang_RX/TX.py error

Post by g4eml » Mon Jul 19, 2021 10:31 pm

That sound device is not one I have seen before. But it appears that you did get it working.

Have you tried connecting the Pluto to different USB ports? Some people have found that it works better when connected to the USB2 ports.

f6itu
Posts: 4
Joined: Sun Jul 18, 2021 6:02 pm

Re: yet another Lang_RX/TX.py error

Post by f6itu » Tue Jul 20, 2021 9:53 am

Thank you, Colin

I had the same reaction an tried all usb ports.

I should mention that my Pluto is a "D" board and is powered via the main usb plug (the "common" data/power plug). I should probably try to use the power plug located on the right side of the box.

I also tried to use a more powerful PSU (the one I use for my HP portable computer, which is a "PD" usb3 psu block able to deliver 65 W). Without any particular success.

I also noticed that the throughput tend to slow down at 450 call per second at the end of the day, when the raspi and Pluto were rather hot.

I also tried to zap the microSD card and reinstall everything from scratch... same error.

This SD card is definitely NOT a C10 class memory. I'll try to find a better device and keep you informed
Tnks again
73'
Marc

g4eml
Posts: 446
Joined: Thu Apr 26, 2018 9:36 am

Re: yet another Lang_RX/TX.py error

Post by g4eml » Tue Jul 20, 2021 10:12 am

Hello Marc,

A slow memory card can certainly cause problems, especially during the initial load.

I have never tried the Langstone with a revision D Pluto so it might be there is some difference there if it takes longer to boot than the older revisions. The slower performance might be down to different firmware in the Pluto, but even with the figure you are getting it should still work OK.

If you are getting problems when starting from boot up it might be worth increasing the delays in the Langstone/run command. You will see several places where there are ‘sleep 3’ commands. If you increase those to ‘sleep 6’ it might give more time for the programs to start.

Colin.

f6itu
Posts: 4
Joined: Sun Jul 18, 2021 6:02 pm

Re: yet another Lang_RX/TX.py error

Post by f6itu » Tue Jul 20, 2021 11:30 am

Tnks Collin

Before touching anything in the code, I'll try to install a new kernel an app on a "serious" SD Card.
I think I flashed the last official Pluto firmware... I'll check this too.

Thanks again for these hints. I'm pretty sure everything will be ok with a better memory card

73'
Marc

f6itu
Posts: 4
Joined: Sun Jul 18, 2021 6:02 pm

Re: yet another Lang_RX/TX.py error

Post by f6itu » Wed Jul 21, 2021 7:02 pm

Hi Collin et All ...

May I suggest a small modification of the wiki ? specify that the read/write speed of the SDcard is not "important" but critical ;-)

Everything is working nice and easy with a high speed memory. Just a quick "Lang_RX.py" error displayed during a brief period of time during the launching of the Python code (half a second, not longer). The waterfall is immediately displayed after this insignificant glitch.

Thanks again Collin. For your support, for your development, for you kindness.

VY 73'
Marc

g4eml
Posts: 446
Joined: Thu Apr 26, 2018 9:36 am

Re: yet another Lang_RX/TX.py error

Post by g4eml » Wed Jul 21, 2021 7:48 pm

Hello Marc,

That is good news. I remember in the early days I decided that the SD card type made a difference but since then it has not been a common problem. Maybe most cards are now fast enough.

Occasional flashes of the Lang_Rx.py message are normal. Maybe I need to increase the timeout value a little.

73
Colin.

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