[Xastir] Raspberry Pi with Xastir

[Ray Wells]

Hi Lee,

It didn't competely dawn on me during early use of of the Pi that the 
supply that was most reliable was the 5.22v mobile phone charger. Back 
then I couldn't do extended running on that ps because it belonged to 
the phone of SWMBO and she needed it every second day. Also back then I 
didn't measure the voltage of that supply, I took its 5v on face value. 
It was only when the DTV dongle crashed so soon and repeatedly on other 
supplies, including clean, linear supplies,  that I checked the phone 
charger more closely.

The adsb Pi is now running from a Murata smps that delivers 5.0v but, 
that Pi has the polyfuses shorted to keep USB voltage as high as 
possible. The new Pi is running from a linear supply set to 5.1v and 
that puts an adequate voltage on the USB sockets - 4.85v from memory.

You might have a point about cpu loading being in the equation. FWIW 
dixprs uses around 33% of cpu. Load average on that Pi is constantly 
around the 1.0 mark but fpac contributes a bit to that. The adsb Pi on 
the other hand shows load average of around 0.4.

I await the outcome of you running higher supply voltage.

Ray vk2tv



On 23/02/14 15:12, Lee Bengston wrote:
> Hi Ray,
>
> I think you were spot on with achieving greater than 5.0 volts as you
> mentioned in one of your earlier messages.  I did some searching around,
> and there are a couple of suppliers of power supplies that are rated at 5.2
> or 5.25 volts that are specifically targeting the Raspberry Pi.  I'm going
> to try something with 5.1 or 5.2 volts and see if Dixprs and/or Xastir work
> better in that scenario. That definitely seems to work well for you.  I
> suspect by running APRX I lightened the load on the CPU enough to get by
> with a more marginal supply.  Top never shows APRX using more than 0.3% of
> the CPU.
>
> Regards,
> Lee - K5DAT
>
>
> On Sat, Feb 22, 2014 at 2:49 AM, Ray Wells <vk2tv at exemail.com.au> wrote:
>
>> Lee,
>>
>> That's good news.
>>
>> I started to get excited once I passed the previously unachievable eleven
>> days!! I'm really ecstatic now ...
>>
>> vk2tv at gateway-vk2tv ~ $ uptime
>>   07:39:38 up 40 days,  8:27,  1 user,  load average: 0.98, 1.03, 1.05
>> vk2tv at gateway-vk2tv ~ $
>>
>> The Pi runs a four port FTDI USB/RS232 adaptor plugged directly into the Pi
>> libax25, ax25apps and ax25tools compiled from Bernard's (F6BVP) sources
>> dixprs with three ports configured
>> fpac running Rose and Netrom nodes via axudp
>>
>> The ADSB Pi is doing even better ....
>>
>> vk2tv at adsb-vk2tv ~ $ uptime
>>   07:45:26 up 44 days,  2:50,  1 user,  load average: 0.40, 0.38, 0.40
>> vk2tv at adsb-vk2tv ~ $
>>
>> It runs sdr-rtl and dump1090 with a DTV dongle plugged directly into the
>> Pi. This is the Pi where I've shorted out all polyfuses to provide a
>> reasonable voltage to the USB ports.
>>
>> Both units run Raspbian and run headless.
>>
>> Ray vk2tv
>>
>>
> _______________________________________________
> Xastir mailing list
> Xastir at lists.xastir.org
> http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir
>