Fight Frost with an Internet of Things Fridge Alarm

It has been incredibly humid around these parts over the last week, and there seems to be something about these dog days that makes you leave the fridge or freezer door open by mistake. [pnjensen] found this happening all too often to the family chill chest, with the predictable accretion of frost on the coils as the water vapor condensed out of the entrained humid air and froze. The WiFi-enabled fridge alarm he built to fight this is a pretty neat hack with lots of potential for expansion.

Based on a Sparkfun ESP8266 Thing and home-brew door sensors built from copper tape, the alarm is rigged to sound after 120 seconds of the door being open. From the description it seems like the on-board buzzer provides a periodic reminder pip while the door is open before going into constant alarm and sending an SMS message or email; that’s a nice touch, and having the local alarm in addition to the text or email is good practice. As a bonus, [pjensen] also gets a log of each opening and closing of the fridge and freezer. As for expansion, the I2C header is just waiting for more sensors to be added, and the built-in LiPo charger would provide redundancy in a power failure.

If frost buildup is less a problem for you than midnight snack runs causing another kind of buildup, you might want to check out this willpower-enhancing IoT fridge alarm.

Old Kindle Upcycled to Emailable Fridge Messageboard

We’ve all got a pile of old devices lying around somewhere that are waiting to be torn down for parts, or turned into something useful. [Peter Voljek] decided to do the latter with an old Kindle eBook reader, turning it into a neat message board that can be stuck onto a fridge. With the addition of some server-side Ruby code, you can send messages to this by email, and it automatically displays the last message received. Throw on some magnetic sticky tape and you have a neat fridge door noticeboard.

[Peter] runs his Ruby web server on a Raspberry Pi, but it should run on any platform that supports Ruby, so you could run it on a NAS device, or pretty much anything that has a web server built in. The Kindle side of the hack exploits some secret commands to disable the screensaver, then uses AJAX and JavaScript to automatically refresh the webpage the RPi is serving.

Hey, why not combine this with the Kindle weather station hack to create a noticeboard that tells you what you need from the store, and reminds you why you shouldn’t leave the house at the same time?

A Beverage Cooler with a Stereo

Cooler

If you are looking for a way to spice up your summertime parties, try following [Pastryboy’s] lead. After letting the idea rattle around in his head for a few years, he finally built himself the cooler he always dreamed of.

[Pastryboy] was originally inspired by a YouTube video he found a few years ago. He took the basic concept and rolled with it. He started out with a mini fridge he found for $10. He removed the compressor and other plumbing bits. He also removed all of the internal shelving. Any leftover holes were patched up with silicone. Now when the fridge is laid on its back, it’s essentially the same as an ordinary cooler.

Next [Pastryboy] purchased two 6.5″ Boss speakers and an inexpensive head unit. He drilled a few pilot holes in the side of the refrigerator and then used a jigsaw to cut the holes to the proper sizes. Once the speakers were mounted in place, he needed to find a way to waterproof the inside. This was accomplished by using some small plastic bowls. The edges of the bowls were attached to the cooler wall using silicone.

[Pastryboy] was able to run most of the cabling through the inside of the cooler’s walls. The system is powered by a 12V lead acid battery. He chose a specific model of battery that can be stored in any orientation and that can handle being knocked around a little bit.

Next he added a couple of handles to the sides to make it easier to transport. A small bit of ski rope was attached to the inside of the lid, preventing the lid from flopping completely open. [Pastryboy] also added a drain to the bottom to make it easier for one person to empty the cooler. The final touch was to pretty it up a bit. He sanded down the entire thing and gave it several coats of red paint. The end result looks very slick.

[via Reddit]

Tweeting beer dispenser requires co-worker approval

tweeting-beer-dispenser

Having been faced with an empty beer fridge one too many times the team at Metalworks came up with an approval system for dispensing malted beverages. The trick was to remove the physical controls on a can dispenser. The only way you can get a cold one is to ask the machine via its twitter account. If there’s beer inside, it waits for one of your approved co-workers to give the go-ahead.

There are two versions of the machine. The first is a hacked refrigerator with a dispenser hole cut in the door. This resides in their Sydney office, apparently doesn’t work all that well, and is only shown in the video after the break.

The image above is version 2.0 which is located at their Singapore branch. It’s a much smaller device, but works very well since it started as a commercially available can dispenser. You can see the Arduino Leonardo and breadboard which make up the driver circuits.

There aren’t a ton of details on this, but it’s not hard to find about a million examples of an Arduino using Twitter. Here’s one that takes Morse code as an input and posts the message as a Tweet.

Continue reading “Tweeting beer dispenser requires co-worker approval”

Cool yourself with a CPU cooler and beer fridge

We have arrived once more at the time of year when penniless (or bored) hackers try to figure out how to keep the place cool without buying an air conditioner. [Paul Stacey] sent us his solution of pairing up a CPU cooler kit with a beer fridge. The CPU heat sink is cut out of a liquid cooling kit and discarded. In its place a loop of plastic tubing enters the freezer of the beer fridge where it exchanges salt water from a reservoir. The cold liquid circulates through the radiator of the fan kit and gives up it’s cool goodness through the fan unit seen above. This method puts a cold-air fan right in front of you with a digital temp and fan speed readout on the LCD.

Our biggest concern here is that this might heat up the beer in the fridge. Still, it’s more automatic than using a homebrew swamp cooler. Then again, we’ve always had a soft spot in our hearts for our favorite gravity fed cooling method. Anyway, check out [Paul’s] build methods after the break where he makes it look quick and easy.

Continue reading “Cool yourself with a CPU cooler and beer fridge”

Energy efficient fridge hack

Green_Freezer

We’ve already covered a pipe bomb mini-fridge this week, but inventor [Tom Chalko] provides us with today’s fridge hack. He noticed that chest-style (laying down, see above) freezers were more energy efficient when compared to normal stand up refrigerators at the same size, despite the colder temperatures involved. This is largely due to the fact that these chest-style freezers keep cold air in like water in a bowl, even if the lid is open. He has written a very thorough report on his findings (pdf), as well as a detailed walk through of the manageable task of converting a chest-style freezer into a chest-style fridge. In the end, his fridge only used 103 Wh of electricity on the first day to reach and maintain between 4° and 7° C (39° to 45° F), and he noted that 30% of that was just getting it up to temperature. After that, the fridge only turned on for roughly 90 seconds an hour, making it a very quiet fridge as well.

Single can mini fridge

untitled

What looks like a potential WMD, requires a huge power supply, and has several fans and wires dangling off the sides? Why a mini fridge of course! Your cubical buddy at work may have a Perfect Coffee Mug, or a USB powered fridge but it wont be as large of a caliber as [CaptPikel’s]. Little information about it is out thus far, but an Instructable is promised. We do however know that it uses 3 peltier coolers (assumed to be 60watt each) and can cool down to 46F while being underpowered! If only it held just a few more cans.