Most Reliable and Stable Setup?


#1

I’ve found a possible new location for my antenna that should improve my reception and reporting compared to what I’m doing here now at the house. It is a remote site, and it will have to be mostly managed through network access as I would have limited access to the site. My concern is that I’m using the Raspi 2 setup and I’ve had to power cycle twice in the last two or three weeks, and i’m not sure what exactly happened. if it was network or something else. Could anyone offer any direction on getting the most stable setup, in terms of software version, what SDR, maybe not even use a raspi at all for this. Any tips or discussion on this appreciated.


#2

Look into the watchdog daemon - the raspberry pi has a hardware watchdog timer built in. You can also set it to reboot under certain conditions, like system load, network connectivity etc.

http://blog.ricardoarturocabral.com/2013/01/auto-reboot-hung-raspberry-pi-using-on.html?m=1

Raspberry pis are quite sensitive to power supply quality, so it would be worth investing in a decent one.

If you are looking at other alternatives, then one of the integrated celeron based boards might be a good choice. They are bigger and use a bit more power, but aren’t quite as compromised as a raspberry pi.


#3

Put a Normally Closed relay in line with the AC power going to the Raspberry Pi controlled with a microcontroller on the same network. If the microcontroller can’t ping the raspberry pi for an arbitrary period of time it opens the relay (turns off the power) for ten seconds in an attempt to restart the device.

Your only worry then is SD card corruption.


#4

I run an RTL820T2/dump1090-mutability/piaware combo on Ubuntu on an Asus Eeebox PC… I have not seen any stability issues at all - 455 days and counting in the stats.

Peter


#5

Same with an RTL820T and all the FA standard package on a RPi under Ubuntu Willy (15.10). Zero problem.


#6

Most stability issues are power related. Put it on a small UPS and make sure you have a quality power supply. I have had no issues with power since switching to these: http://www.microcenter.com/product/441187/Micro-USB_Power_Supply_for_Raspberry_Pi_B_with_Built-in_4ft_Cable_-_2_Amp

Cheers!
LitterBug


#7

All good stuff guys, thanks. Watchdog daemon and power supply are two things I can implement easily as there is a microcenter fairly close to me. I was also reading somewhere about a network daemon that resets the connection if it detects a lost connection. I will be looking a bit more into that too. Thanks


#8

keep it simple with the fewest possible components.

Avoid power injectors and amplifiers if you can. More parts, more potential sources of failure.
Ethernet connection, no wifi.
give it a static ip address in the upper range. You do this to minimize conflicts that can occur with other devices or when someone does a hard reset of the modem.
use a cron to cycle the raspberry once a day (in the night).
use something like weaved.com to get you in for troubleshooting or resetting the ip configuration file when things go wrong.

And perhaps most important, locate it somewhere where the power plug will not be accidentally knocked loose.


#9

You may have a bad Pi or a failing SD card. If your power supply is sufficient I’m not sure why the unit should hang such that you would require a power cycle. Before I just rebooted it (swapped cards), I had 6 months of up time with my Pi in the attic that’s gone through deep freezes and amplified sweltering summer heat.


#10

So yeah, power will be the first thing I address. I’m using a power supply that’s supposed to be 3 amps and it has a usb connection. I bought two at the time, one happened to not work right out of the box, so there’s no telling what the output actually is. I have a steady red most of the time with some occasional flashes. I’ll just get the recommended one that is a direct to micro usb and eliminate possible problems with another usb link or possible bad usb cable. It gets brutal up in my attic it might desolder the board!


#11

You have discovered, without any question, your problem! The red LED isn’t a system controlled light, or anything like that. If it has flashed, the voltage has dropped low enough for the 3.3v feed to drop out. You have a bad power supply.

If you have been crashing the system often, you may now have corruption on your SD card. It might be good to wipe it and start fresh. With a correctly operating system, it should have an uptime of years. Some think these things are like Windows machines that just “break” and need to be restarted. A correctly operation system will not. Make sure you add a UPS.


#12

There’s more to a power supply than it’s rated output. You need one that provides a clean DC output. Many phone charger types are poorly controlled and very noisy with ripple and other undesired components. It’s hard to judge this without testing it on an oscilloscope under load, but I would buy one from somewhere that supplies stuff specifically for use with Raspberry Pis. In the UK I bought a 5.2V 2A supply from Modmypi.com, and it has been very good. The slightly higher output voltage helps to overcome cable loss, and so provide 5v at the power input on the Pi.


#13

Quote from Wikipedia’s “AC Adapter”:

*"Dangerous and unreliable adapters
Manufacturers of equipment supplied with AC adapters often supply replacements at high prices; this has encouraged the manufacture of compatible third-party aftermarketreplacements, which may be of satisfactory quality and performance at significantly lower prices. However, some adapters, usually at very low prices, and sometimes with unknown brands or sometimes fraudulently marked with the name of a reputable manufacturer, have various deficiencies which can cause inadequate performance (e.g. poor regulation and ripple, maximum power capacity lower than specified, hot running), unreliability (e.g. overheating to temperatures exceeding component ratings), and electrical or fire danger to users (e.g. insulation which frays with wear, lack of fuse).

Spurious marks of conformity to standards may be present; in one case it was reported that “Chinese manufacturers were submitting well-engineered electrical products to obtain conformity testing reports, but then removing non-essential components in production to reduce costs”. A test of 27 chargers found that all the eight legitimately branded with a reputable name met safety standards, but none of those unbranded or with minor names did, despite bearing the  mark of conformity."*


#14

Regulated Power Supplies have:
(1) Good output voltage regulation (see diagrams 1 & 2 ), so that:
— No-load voltage is not too high from rated voltage.
— Full-load voltage is not too low from rated voltage.

(2) Filtering of ac ripple so that output dc voltage is constant (see diagram 3)

Diagram 1 - variation of output dc voltage with load current.

Diagram 2 - Comparison of Regulated switching mode vs Unregulated dc supply.

Diagram 3 - Ripple in dc output before (gray) and after (red) regulation & filtering.


#15

I’m going to setup a remote site and link the device to 3G. I’ve had experience at home with a bog standard raspberry crashing, why I have no idea ie: voltage, SD card, who knows but I’ve got real 5V at the PI with lots of current.

I’m planning on an arduino with a 1 minute timer that will get reset via a python script (cron job) on the raspberry that will toggle a GPIO pin. If the raspberry stops, the Arduino will toggle the power…

Stuff happens no matter how well you build it, an external watchdog of some sorts is a very good idea.

Pete


#16

for a remote site - I’d be tempted to use something akin to a UPS, but constructed from a 12v rechargeable battery ($15 amazon), a 5v converter with micro USB ($2.82 ebay.com/itm/311426802775 )


#17

I am thinking about using a powerbank (with 2A output) as a UPS… Would be cheap and easy.

enigma14.eu/wiki/5V_UPS_for_Raspberry_Pi


#18

Be careful with the powerbank idea. They really were not designed to be a UPS. You may find that you can not charge and provide power at the same time. (says so right in the link you provided too) They are usually built around LiPo batteries, which can be very hazardous if the charge controller is not smart. I personally use a UPS out of convenience. I have everything gathered up to do the “DC-DC Converter from 12V to 5V USB” method shown in your link using solar panels as the source.

Cheers!
LitterBug


#19

I have found the rpi internal watchdog to be effective, the arduino probably just adds more complexity and things to go wrong. Here are some options.
http://www.instructables.com/id/Raspberry-Pi-and-Arduino-Building-Reliable-Systems/


#20

I’d be a little cautious if you’re planning on running a larger site. I average about 36kbps (max about 90kbps) over a 24 hour period feeding Flight Aware, my Virtual Radar Server, and another group, so cut that to a third and I’m still running 4GB a month just for Flight Aware. That’s a lot of cellular data.