Another beer refrigerator

I wanted to run this by everyone to see what you think. This is my first Arduino project and it was a blast!! :)

And here is the link...

http://danielwood.name/blog/2009/02/15/1234763760000.html

From the graph it looks like you've been grabbing a beer from the fridge about every 15 min starting at 8am..... a little early don't you think? ;)

Looks like a cool project though. Too bad there needs to be that 10min delay inbetween the compressor runs, but i know its necessary to prevent damaging it.

Sweet! Interesting take on using a freezer instead of a fridge. I would never have considered that.

Here’s some ideas for you to toy with if you care to:
o Since heat rises (and cold sinks), you could give it two temperature sensors: one at the top and one at the bottom. Then if the difference between the sensors goes beyond a certain value, kick on the air circulation fan, this may help prevent the compressor from running unnecessarily and will assure that the beer on the bottom rack is the same temp as the beer on the top rack.

o Mass is more temperature stable than air. So you may be able to cut down on compressor cycling further by attaching the temperature sensor(s) to a chunk, slab or piece of copper or aluminum. This will slow down the response to temperature changes and prevent the occasional door opening from tripping the temperature sensor immediately.

o You could sense the door light switch and add a timer that prevents the system from turning on too quickly and runs the circulator fan instead after the door is opened. This will allow time for the contents of the fridge to cool the air, rather than cycling the compressor to do it. This will really help during the Super Bowl and UFC fight nights.

YMMV on all of these. I just like to experiment with this kind of stuff and over engineer a little. :slight_smile: But let us know if you do decide to implement any of these. I’ll be interested to know the outcome.

Thanks for the ideas. I updated the blog with a couple things I’ve done over the past couple days. I added a photocell to detect when the door opens and a much bigger circulation fan that remains on all the time (well almost all the time).

What I was finding is that when compressor shut off, the air temperature went up quickly. Adding the high velocity fan balances things out significantly. But there would be someone at some point that would get some cut knuckles grabbing something off the bottom shelf. The interrupt shuts the fan down immediately when the door is open. The fan then resumes on the next loop() if the photocell pin is high.

I now log when the door is opened as well :slight_smile: … because I want to make sure that I can keep an eye on things when my kids get older. I could put a lock on it, but I would rather trust them initially and catch them in the act. Heh heh

http://danielwood.name/refrig/door.jsp

I now log when the door is opened as well ... because I want to make sure that I can keep an eye on things when my kids get older.

HA HA! That may turn out to be the most useful feature! ;)

I am not sure if it is appropiate to post this here, but if you like beer enough to make something with Arduino to keep your beer on the right temperature you probably don’t want to miss this commercial:

Haha! that commercial is funny! That’s how I felt when I finished mine.

Wow! 28.5 degrees C, thats pretty warm for beer! ;)

28 degree Fahrenheit = -2.2222222 degree Celsius

I found that at 28 degrees F, beer does not freeze. Coke does not freeze. Diet coke on the other hand is unpredictable. Most would stay completely liquid, but there were a couple that exploded. I think it's due to a difference in carbonation, but who knows and who cares?... this is meant for one purpose. To chill the goodness we have come to know as beer!

Oh, sorry. Your code specifies the LM35 which is a celcius sensor.

Nice catch. I started with the LM35 but then went to a LM34 later. Thanks! I will update the code.