Gadget Freak Case #118: Spying on Your Freezer

You can accomplish the same thing for free
you put an ice cube in a closed container
to avoid evaporation, and if you come back from vacation and the ice cube has melted and refrozen in the bottom of the container your freezer power
was interupted for a time

Can we get the PIC code as well?

I'm a big fan of the ice cube method. But....

a high tech thing that could have real value
would be a delta temperature/delta time detector
that detects that the freezer has quit long before
the food becomes unfrozen. That would have saved
the $1000 in meat I had in a freezer that at least
I had my ice cube in and didn't eat.

Jerry Steele

I would just like a simple device that will sense temp risen to -9 degrees C and open a pair of NC contacts to trigger my cheap wireless pager alarm to warn house a problem, my garage freezer is 20m from house.
I am working out if I power a small relay from the freezer red warning light to open a pair of contacts to trigger wireless pager alarm. There is a sensor with a probe on market but it gives accasional beep and LED lights, if that could open or close a pair of contacts it could be adapted easily. If I know freezer has failed I can move contents to a standby freezer without any loss of food. I will make an ice cube tub also as if away and a power cut it would let you know.

I the same problem with the freezer at my cabin, only being there on weekends there was no way to tell it had thawed and refrozen. A friend of mine who worked in infection control at a local hospital told me how they monitor freezers that employees use for food. They fill a paper cup with water, freeze it, and then put a penny in the cup. If the freezer thaws and refreezes the penny will be frozen in the ice.

Jeff

It would be trivial to add an alarm to the thawed-ice solution with a normally closed mechanical switch with the arm pressed against the top of an ice cube, or perhaps a mercury switch which tilts upon the melting of the ice, or for that matter, tin foil contacts separated by a piece of ice...

I think that it's interesting to note the number of "engineers" that love the melting ice cube solution -- especially since it doesn't meet the problem's specified requirements.

It might be a little bit of a stretch to assume that being able to hear the water melt/freeze constitutes a satisfactory alarm.

Call me old-school, but I thought that satisfying requirements was what engineering was all about.

The submitted code listing has been neglected to be included with the build instructions. This missing file can be requested by contacting the author at contact@riverheadsystems.com

According to the Article, the controller 12F509 is programmed and ready to use. Will you provide the chip and how can I contact with you?

Any chances of getting the code for the PIC?