Raspberry Pi 4 Released - Don't Buy for Portsdown

Discussion about this major DATV Project. See also https://wiki.batc.org.uk/The_Portsdown_Transmitter
gi7ugv
Posts: 40
Joined: Tue Oct 31, 2017 2:47 pm

Re: Raspberry Pi 4 Released

Post by gi7ugv » Tue Jul 30, 2019 2:47 pm

gi7ugv wrote:
Sat Jul 06, 2019 11:32 pm
After some use it’s looking like it would really benefit from a fan for cooling. Under heavy load the CPU quickly throttles significantly. A small heatsink helped a little but not enough for my use, will try a fan next.

There’s firmware being tested that might reduce temperatures too but it seems this Pi is going to need more thought with regard to heat than previous ones.
Not for Portsdown as already said but just an update for anyone interested to say that a fan makes a huge difference to the Pi 4. My Pi 4 is maintaining itself at 52C while transcoding a stream with ffmpeg and using limesdr_dvb to transmit. Previously with just a small heat sink it would work for under 10 minutes before hitting 80C and throttling the CPU breaking ffmpeg.

GM4JOJ
Posts: 2
Joined: Tue Feb 14, 2017 12:04 am

Re: Raspberry Pi 4 Released

Post by GM4JOJ » Tue Jul 30, 2019 4:15 pm

[quote=gi7ugv post_id=20415 time=1564498072 user_id=15483]
Not for Portsdown as already said but just an update for anyone interested to say that a fan makes a huge difference to the Pi 4. My Pi 4 is maintaining itself at 52C while transcoding a stream with ffmpeg and using limesdr_dvb to transmit. Previously with just a small heat sink it would work for under 10 minutes before hitting 80C and throttling the CPU breaking ffmpeg.
[/quote]

If you've got 15 mins to spare you might be interested in this YouTube video that demonstrates how various cooling methods applied to the Pi 4 affect the CPU temperature. Fitting a fan makes a lot of difference.

https://www.youtube.com/watch?v=AVfvhEJ9XD0

F1BFU
Posts: 20
Joined: Sun Aug 04, 2019 1:53 pm

Re: Raspberry Pi 4 Released - Don't Buy for Portsdown

Post by F1BFU » Mon Aug 05, 2019 12:35 pm

Hello

with Portsdown 2019 is it possible to replace the LimeSDR with an Adalm Pluto?

Gilles F1BFU /FR

G8GKQ
Site Admin
Posts: 1307
Joined: Sun Mar 22, 2009 1:21 pm

Re: Raspberry Pi 4 Released - Don't Buy for Portsdown

Post by G8GKQ » Tue Aug 06, 2019 3:58 pm

Hi Gilles

No. No-one has yet written Linux software that will transmit DATV from the Pluto and is capable of running on a Raspberry Pi.

I am not clever enough to do it, but if you can find the software, I could try to put it into the Portsdown project.

Dave, G8GKQ

g8lce
Posts: 76
Joined: Sun Dec 06, 2015 10:26 am

Re: Raspberry Pi 4 Released - Don't Buy for Portsdown

Post by g8lce » Wed Nov 06, 2019 10:18 am

Hi Dave, G8GKQ

From your comment about not supporting RPi 4 I read that it is only the touchscreen that does not work. Does this mean that I could control Portsdown remotely (as I do with the RPi 3 ) or am I reading too much between the lines?

I use a remote RPi with Portsdown for Oscar 100 and in the future for TXing to GB3NQ. The extra speed for dealing with signals may be a benifit.

If someone wrote a remote control program that ran in Windows 10 and echoed your touchscreen that could then be used as a remote screen or a local screen instead of the 7 inch touchscreen. (if there are any cheap chinese touchscreen windows 10 tablets )

I also have an interest in astronomy and recently there has been a project that has produced a RPi program that runs the astronomy bits but also turns the RPi into a WiFi hotspot if no WiFi or LAN is detected. You can then connect to it from your computer or Phone and control it if say you were on top of a hill.
https://indilib.org/forum/general/5524- ... vised.html

NOTE that I know that all I am doing is using all the hard work of others and owe them a big thankyou.

Martin G8LCE

G8GKQ
Site Admin
Posts: 1307
Joined: Sun Mar 22, 2009 1:21 pm

Re: Raspberry Pi 4 Released - Don't Buy for Portsdown

Post by G8GKQ » Wed Nov 06, 2019 10:41 am

Hi Martin

There are 2 issues with the Raspberry Pi 4. The first is that the software I use for the touchscreen is no longer supported. The second is that it needs an upgrade of the operating system. Currently Portsdown works with "Stretch" and the RPi4 only works with the newer "Buster".

I am currently developing and testing a new RPi3/3+ Portsdown build using Buster to overcome the operating system issue. The only major issue that I have found so far is that FreqShow (the spectrum view) does not work properly. However, there is at least another month or so's work until I will be able to publish the new release. After that, I will test it without a touchscreen on the RPi4, so what you are proposing may be practical.

Once I have the basic transmitter working on the RPi4 I will start looking at a redesign of the touchscreen control, initially focussed on the LongMynd receiver to take advantage of the H265 hardware decoder. It may end up being a Python program that could run on either a Windows or Linux environment.

I had considered including a WiFi hotspot in the Portsdown system, but it has never got to the top of the to-do list. Thanks for the link - I'll take a look and see if it would be easy to incorporate the functionality.

Dave, G8GKQ

g8lce
Posts: 76
Joined: Sun Dec 06, 2015 10:26 am

Re: Raspberry Pi 4 Released - Don't Buy for Portsdown

Post by g8lce » Wed Nov 06, 2019 10:56 am

Hi Dave,

I have just realized he most obvious way you could go maybe!

Use the old touchscreen RPi that you know (and love? ) and use it to control the next generation RPi 4 Portsdown software.

That would recycle the equipment we already have while progressing to faster RPi's

As an aside I have started using some AMX 3155HDs for routing video around. They can be controlled from a web interface and will reconfigure video and audio. They also produce test signals. As they originally cost thousands they are now less than £100 on Ebay. Have a look at the specs etc. online. They can be sent commands and have various relay outputs etc. but just the simple web interface does most of what I need. There may need to be a new topic about this sort of stuff as there are other bits that are useful ie. AMX 1100.

Martin G8LCE

Post Reply

Return to “The Portsdown Digital ATV System”