[pskmail] Re: server on Rasp Pi or Beablebone Black

  • From: Ian Bennett <ibennett@xxxxxxxxxx>
  • To: pskmail@xxxxxxxxxxxxx
  • Date: Fri, 29 Aug 2014 18:14:34 +1000

Per,
        Not sure where your noise is getting in however I find I need to 
"choke" wall warts to within an
inch of it's life :-)
        My problem is getting RF into the DC supply and find toroids rescued 
from UPS especially useful. I
wind as many turns as I can of the DC output from the power supply around the 
toroid. Not only does
this keep the RF out, it also makes the installation very neat as the power 
supply cables are now
very short :-)
        This procedure is standard for anything I use. Not sure if it is making 
any difference but it makes
me feel better :-P

Ian
VK1IAN


On 29/08/14 18:01, Pär Crusefalk wrote:
> Hi,
> 
> I did have the Pi run a minecraft server for the kids prior to making it run 
> pskmail.
> Minecraft can be quite demanding, it certainly is very demanding when many 
> players are using the
> server and so I overclocked it.
> By looking at the blog entry about that I was quite happy to do some 
> overclocking as it should be
> perfectly fine to do so:
> http://www.raspberrypi.org/introducing-turbo-mode-up-to-50-more-performance-for-free/
> The raspberry will reduce the speed if it should get too hot, mine is not hot 
> at all but I have
> applied all the heat sinks that are available for it.
> 
> Yesterday I put a new PSU there that did not QRM as much as the old and 
> decided to launch the server
> again.
> Sadly I can now not launch fldigi as it dies complaining it could not find 
> /proc/cpuinfo. I
> recompiled fldigi but had the same issue so something has happened to it. 
> Perhaps some other upgrade
> has affected it. I will try to get some time to make it work again this 
> weekend. When I did have it
> running it did not consume very much cpu, not even when doing PSKR.
> 
> 73, Per
> sm0rwo
> 
> 
> 
> 
> John Douyere skrev 2014-08-29 03:31:
>> Hi Greg,
>>
>> I can't remember saying it was not powerful enough, just that the THOR modes 
>> are more demanding
>> that most of the other modes.
>>
>> If I remember well the discussion thread I was asking if the CPU load was 
>> not too high on
>> Raspberry PI as the OM could not decode PSKR modes. In the end the issue was 
>> not with CPU load but
>> a bug in the Fldigi PSKR code.
>>
>> The OM also reported that THOR modes could be decoded.
>>
>> Having just converted a few Fldigi modems into Android using not the Java 
>> language but C++
>> *natively *I have some reasonable idea of the capability of some of these 
>> ARM CPUs without the
>> Java overhead.
>>
>> For example a rather old HTC Desire phone can decode PSKR, THOR, OLIVIA, 
>> MFSK and even MT63 2000L
>> without problems. The CPU load does not exceed 50% which leaves enough room 
>> for other processes.
>>
>> Looking at the results of benchmarks like the Whetstone Native (not Java) 
>> benchmark results for
>> Raspberry PI on the net I find values of 95 MFLOPS at 700Mhz CPU clock (the 
>> default I understand)
>> and 134 MFLOPS at 1000Mhz clock speed (over-clocked).
>>
>> Compare this to the results of 120 MFLOPS for my HTC desire mentioned above 
>> and you can see that
>> it is very comparable. So in my opinion it should work on a Raspberry PI, 
>> ASSUMING that there no
>> significant extra overheads introduced by the GUI side of Fldigi + O/S.
>>
>> I don't know what Per has done to make it work in terms of configuration but 
>> I would suggest
>> looking at the following:
>>
>> - Overclock the Raspberry PI to 800-900MHz (Do some research here as it 
>> seems to be the maximum
>> acceptable long term continuous running overclock limit).
>>
>> - In Fldigi:
>>
>> 1. Set the slow CPU option ON.
>>
>> 2. IN THOR modem disable filtering, soft-symbol and soft-bit decoding.
>>
>> 3. In Audio / Settings I would choose either Linear interpolator or Fastest 
>> Sinc interpolator.
>>
>> - Finally and it can be important on some devices, run Fldigi minimized. 
>> This reduces the GUI
>> processing quite significantly regardless of the settings of the waterfall.
>>
>> Maybe Per can detail his configuration to make it work on the Raspberry PI.
>>
>> I believe the Banana PI with it dual core 1GHz ARM-V7 architecture 
>> (including hardware floating
>> point unit) should provide a much lower CPU load when running Fldigi and a 
>> Pskmail server.
>>
>> Hope this helps,
>>
>> 73, John (VK2ETA)
>>
>>
>>
>>
>> On Thu, Aug 28, 2014 at 2:01 AM, Greg <kb1ncj@xxxxxxxxx 
>> <mailto:kb1ncj@xxxxxxxxx>> wrote:
>>
>>     Greetings Group,
>>
>>     I see people mention they are setting up servers with these new micro 
>> devices.. I thought I
>>     remember when I asked about this maybe a year ago, John (VK) I think 
>> said that they were not
>>     powerful enough especially with the THOR modes... Still true? I would 
>> switch my server out
>>     just to save on electric use.
>>
>>     Also my server was on boot stuck for a few weeks but back on now..
>>
>>     Greg
>>     KB1NCJ
>>
>>
> 

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