I am using an Arduino UNO and the new Ethernet Shield. After about 2 hours the connection is lost. I am using the hard wired reset and watchdog timer techniques but they aren't helping - the reset works for the first 2 hours, but only a full power off works afterwards.
Any assistance would be appreciated as it is very annoying to have a project which works and then stops.
having a lot of experience with ethernetmodules with arduino; whatever you do (i tried and manipulated a few different libraries) also i used some different boards. Essentially it boils down to: too bad for us: you are going to have to reset it every once in a while. Sometimes thats 48hours, sometimes 1hour. It usually performs better when you do not make multiple connections.
As it is being used as an unattended energy monitor I can't power it off manually. I see lots of Arduino powered Pachube feeds how are they coping?
Boy I sure hope I don't tempt the chump gods here 
but I'm doing a Pachube feed (actually three feeds via the same unit, one update per minute each) and it just seems go keep on going. Also does NTP but only once an hour (yes that's probably overkill).
I think in the past someone has posted that they had a remote setup that has operated unattended for months without issues. You might try some searching of this and the old forum.
I'm using Duemilanove + Ethernet shield (http://cgi.ebay.com/Arduino-Ethernet-Shield-Based-Wiznet-W5100-Ethernet-/110671878038?pt=LH_DefaultDomain_0&hash=item19c48ed796) + XBee Shield (http://cgi.ebay.com/Arduino-IO-Expansion-Shield-V5-Xbee-Sensor-Shield-RS485-/110673784430?pt=LH_DefaultDomain_3&hash=item19c4abee6e) + XBee(Serial 1). I never encounter your problem. It works all day long at home. And I can access it any time in my office.
Is there any defect on you hardware? Can you have a try with another Ethernet Shield?
BYW, what Ethernet Shield are you using?
Thanks,
Jeffrey
I noticed that the ethernet died for various reasons after only a couple of hours operation. After searching the web I realized that, as the author above put it, "too bad for us" and decided to take a different approach. I check the connection using various techniques on different devices and reset the darn board to reestablish the connection. Some of the techniques are: Hardware modifications to the ethernet board to make sure it actually connects to my network. I have seen many, many problems with this. I connect to the dsl router every so often to be sure that path works. I count the times my pachube update path fails on a connection and reset if necessary. I connect between machines inside my network to be sure they can talk to each other, and again, reset as necessary. I carry it all the way to reseting the arduino if I suspect there is a problem. The reason this works for me is that the arduino takes seconds to reboot, not minutes and there's no operating system to get in the way of it coming up every single time. Heck, we even have eeprom to store things in before we reboot so we can pick right up where we left off.
This may sound like overkill, but I'm also using my little machines to monitor power, control two heat pumps in the Arizona summer heat, and present an interface where I can adjust these things as necessary to keep my power bill down. It could cost me money if they fail.
My most recent effort in this is to replace some of the ethernet devices with XBees to reduce cost and increase reliability. Time will tell if this is working. At least I'll only have a small number of ethernet connected devices to worry about.
I suspect it might be something to do with my router - I will try it tonight passing through my laptop and report back.
The Ethernet shield is the new one with the micro SD.
I suspect it might be something to do with my router - I will try it tonight passing through my laptop and report back.
The Ethernet shield is the new one with the micro SD.
There is always the possibility that bad code is the issue.
I used a different router and via Internet Sharing and it still failed after 50 to 100 minutes.
I've tried programatically resetting the Ethernet Shield and Arduino and it doesn't work unless a full power off is performed. The code works for 50 minutes and the memory doesn't seem to be leaking (using MemeoryFree) so I don't think it is bad code.
I think in the past someone has posted that they had a remote setup that has operated unattended for months without issues.
That could have been me. I have a remote connection that has worked largely without issue since 2009. I've needed to reset it once in that time. A remote server pulls a page from it once a minute.
The server's page is here :
http://pluggy.is-a-geek.com/index.html
The church graphs at the bottom are what it gets remotely from here :
This just a Duemilanove with a early type wiznet shield.
Marsflyer, take a look at one of my pages (Desert Home: Super Thermostat) where I addressed this particular problem. The actual code has changed some since then and I have figured out even more ways to sample failures and correct for them. However, with an Exacto Knife, wire and some inventiveness I have a system that is available every day, all day. Sure it fails and self corrects, but it's always there when I interrogate it.
Another etrhenet shield link that might be of interest.
Fixed - it was a combination of hardware and software! I used a digital output wired to the Ethernet reset (with bent reset pin and ICSP cut so it doesn't reset the Arduino), but needed to reset for 4 seconds to ensure a full (power off style) reset.
The software error was because I had enabled the watchdog timer reset after 8 seconds which happened sometimes.
I've messed up and left a watchdog timer running a couple of times. It was a real surprise when it rebooted for no reason; at least I accused it of not having a reason. Nice job, I really think they should consider giving the board it's own reset that we can get to programmatically to allow for the unexpected. Mostly because the unexpected seems to be the usual in my case.
Now you'll start looking for things that can hang it up and it'll get even more reliable.
¿temperature problem? I have the same problem and I think this is de problem.