Thanks for the continued responses.
My code is fairly stable at the moment thanks to storing all my strings in flash. But it will still freeze up, after a few hours of operating as expected, right after it connects to thing speak. Once it does freeze up, the only way for it to reestablish a connection to thing speak is by cycling power. Pressing reset does not work. Resetting will restart the code but I continually get my message saying that a connect to thing speak failed.
Graynomad:
That's because the function returns when the last character is written to the UART, but at that point it hasn't been transmitted. The delay will get you out of trouble but you really should test the appropriate UART register flag.
Rob
How do I go about doing this? I did a quick search but I didn't find anything very specific.
draythomp:
I have had significant problems with the ethernet shield hanging up. When I try to use it for an extended period, it will eventually fail to connect in some fashion or other and there is no easy way to get it working again. Yes, I know all about the reset problem that they fixed with the new board, but that isn't what was happening. The code or board would just fail to connect to whatever web service I was trying to reach. I solved this by working up some code and hardware changes that senses when this happens and resets the ethernet board, if it still fails, I reset the arduino. This requires logic to recover from a reset and storing some critical values in rom, but it works now.I've used several of the boards and this is a consistent problem over all of them so I suspect code problems either in the library or the code on the 5100. Other folk have experienced this same situation when they are trying to use the ethernet to store data over long periods of time. Our advantage in this is that the arduino can reboot and pick up where it left off in a few seconds making such a thing possible. There's the added advantage of my devices can survive a power failure just fine, hardly a hiccup.
Thanks draythomp. I actually came across your site while researching my issues. I will likely have to do the same things you did.