Langstone Update 28/05/20

Forum for discussion about the Langstone Microwave Transceiver that shares some features with the Portsdown. Wiki: https://wiki.microwavers.org.uk/Langstone_Project
G8IKP
Posts: 6
Joined: Tue Jun 25, 2019 11:01 am

Re: Langstone Update 28/05/20

Post by G8IKP » Fri Jun 05, 2020 8:44 pm

I'm sort of glad to hear, as I have had these problems since I did my first Langstone build. I was trying different power units a different Pluto and a complete rebuild of the SD card but it stopped after about 30 seconds on a new SD rebuild then subsequent reboots lasts about 5 seconds before freezing. John
John G G8IKP

g4eml
Posts: 252
Joined: Thu Apr 26, 2018 9:36 am

Re: Langstone Update 28/05/20

Post by g4eml » Fri Jun 05, 2020 9:36 pm

John,

This problem only occurred in the last few days. If you were having problems before that then you have a different fault.

Colin.

G4FKK
Posts: 55
Joined: Sun May 05, 2019 12:15 pm

Re: Langstone Update 28/05/20

Post by G4FKK » Sun Jun 07, 2020 12:48 pm

Hi Colin,

You may remember I reported intermittent tx/rx switching delays recently. I've noticed that disconnecting the Langstone from my LAN appears to make the switching entirely reliable - well, so far at any rate. I wonder if that's a clue to something in the coding or whether my LAN is doing something it shouldn't?

73, Martin - G4FKK

g4eml
Posts: 252
Joined: Thu Apr 26, 2018 9:36 am

Re: Langstone Update 28/05/20

Post by g4eml » Sun Jun 07, 2020 1:52 pm

Hi Martin,

The Pluto, although connected with USB actually appears to the software as if it is a network device. I suppose activity on the Pi’s network port could conceivably cause the response time of the Pluto to slow down.

Just out of interest what is the network address range for your wired network? The Pluto by default sets up a network address of 192.168.2.x , if your wired network also uses that range then the Pi might have difficulty working out where to send the Pluto commands. If you do have an address clash then it is possible to change the Pluto to use a different subnet.

I don’t see any difference on my system with the Ethernet connected or not.

Colin.

G4FKK
Posts: 55
Joined: Sun May 05, 2019 12:15 pm

Re: Langstone Update 28/05/20

Post by G4FKK » Sun Jun 07, 2020 6:02 pm

Thanks for that Colin,

My local address range is 192.168.102.nnn (for various historical reasons), and I haven't changed the Pluto's address. I just realised I haven't installed a pullup on pin 11 (PTT), so maybe some odd earth-loop is putting some noise on it when the network cable is plugged in?

73, Martin - G4FKK

g4eml
Posts: 252
Joined: Thu Apr 26, 2018 9:36 am

Re: Langstone Update 28/05/20

Post by g4eml » Sun Jun 07, 2020 6:55 pm

You do need additional pull-ups on the input pins. Even though I have enabled the built in pull-ups they don’t seem to be very effective.

Colin.

g0mjw
Posts: 1259
Joined: Sat Sep 20, 2014 9:15 am

Re: Langstone Update 28/05/20

Post by g0mjw » Sun Jun 07, 2020 8:18 pm

I read that: "wiringPi pull-ups and pull-downs do not work on the Pi4B. The ways the pulls work has changed in the new BCM2711 SoC used in the Pi4B"

and there needs to be a new version but it's not being maintained. Howver someone else is on it - see https://github.com/WiringPi/WiringPi

So maybe it's software but I just used a 3k3 resistor and it works fine.

Mike

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