[OZAPRS] VK2XSE IGate

[Ray Wells]

My first attempts to use the Pi for an aprs gateway were anything but 
successful, with wifi failing anywhere from a few hours to ten days, the 
latter being the longest uptime without a failure. I tried a variety of 
power supply arrangements and looked at supply cleanliness, as well as 
voltage. I then moved away from the Pi.

My return to the Pi was with a DTV dongle for adsb. With one supply, a 
700mA phone charger, the Pi seemed happy but with other supplies the 
adsb program would crash within seconds. Significant here was the phone 
supply produced 5.22v whilst all others sat just under 5v. I bought a 
Murata 5v/1.5A smps and mounted it inside a commercial 12v/5v cigar 
socket style USB charger thingy. I also shortened the USB lead from 
about 1m to around 300mm.  I shorted all polyfuses. That Pi has just 
passed 26 days uptime.

Armed with that success I again set up another Pi for aprs gateway 
service. Although it's overkill I used a 3.5A linear supply (LM350) that 
I already had on a heatsink. I set the voltage to 5.1v and that Pi, 
which drives a four port USB/RS232 FTDI adaptor, has now passed 22 days 
uptime. With both Pi's I use Ethernet and get to the wifi LAN via an 
ethernet/wifi bridge.

It seems that voltage for the Pi is even more critical than I initially 
believed. I believe that the voltage at the USB ports, under load, is 
particularly critical to reliable performance.

Ray vk2tv


On 05/02/14 18:31, Steve wrote:
> I had to go hunting for your bottom post ;-)
>
> Here's a uname -r from one of mine. It was last rebooted when I did 
> the apt-get update/upgrade to get it to this state:-
> Linux sandhills 3.10.25+ #622 PREEMPT Fri Jan 3 18:41:00 GMT 2014 
> armv6l GNU/Linux
>
> To be honest though, most of the problems were sorted by the time your 
> kernel was released so I'm still a bit surprised about your 
> reliability problems.
>
> I'm probably not telling you anything you don't already know, but the 
> Raspberry Pi's are very sensitive to power input. If I see 4.7v across 
> TP1 and TP2 I start to get worried. If using the Micro USB connector, 
> a good power supply can be crippled by the I2R losses across a poor 
> USB cable. Using that USB port for power puts the Pi on the back foot 
> to begin with I reckon.
> I feed power in via the GPIO header most of the time.
>
> Anyway, good luck!
>
> VK2ZSZ
>
>
>
>
>> uname -a
>> Linux car-pi 3.10.1 #2 Tue Aug 20 10:36:16 EST 2013 armv6l GNU/Linux
>>
>> running some apt-get commands now if an update will help
>> (raspbian is the distro)
>>
>>
>>
>>
>> -+-+-+-+-+-+-+-+-+-+-+
>> Liz
>> VK2XSE
>> _______________________________________________
>> OZAPRS mailing list
>> OZAPRS at aprs.net.au
>> http://lists.aprs.net.au/mailman/listinfo/ozaprs
>>
>>
>
> _______________________________________________
> OZAPRS mailing list
> OZAPRS at aprs.net.au
> http://lists.aprs.net.au/mailman/listinfo/ozaprs
>