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You might want to check price on edimax IP-1500/1510 ethernet webcam. The picture is not high in resolution, but the price is over here under US$50.

There is also one more option to be considered. Since there is not much data to be transfered (~1kb text or ~40kb with one image), maybe ham packet ...

Using dial-on-demand is an option, but rather hard one. There were very convenient devices, such as Orinoco RG-500, first gen. Apple AirPort and similar that could take care of it for You, and I am shure that they are very cheap second-hand, as the RG is out of production for years now. They all can ...

If You use formula for calculating dew point from http://en.wikipedia.org/wiki/Dew_point the result is -infinite, or in our case minimal negative -99.9F (that equals -73.3C).

Therefore, It is most likely software problem. From what I see, it looks like dew point should not be calculated if humidity ...

The problem is that pcengines.ch (they make Alix boards) are shipping them with switching PSU-s. As such, switching (electronic) PSU is much more efficient than "standard" - brick PSU, but is also more sensitive to power fluctuations and noise.

I would suggest avoiding UPS and just buying brick ...