A Raspberry Pi post for Pi day

I’ve recently fallen in love with Raspberry Pi computers again. The discovery of MQTT and io.adafruit.com for data logging lead me to Node Red.

Node Red is awesome! It’s like scratch programming for things!

Monitoring a fridge is as simple as drawing a few lines between some boxes.

For example. My fridge is starting to have some issues. It wants to keep freezing everything in the fridge. It dials the temperature setting all the way up and we don’t know why. I’ve taken the fridge apart as best as I can the last time we defrosted it just to wiggle all the wiring connections.

A quick gauge showing me the current fridge and freezer temp.

I wanted to really see what was going on with the fridge. I grabbed a Raspberry Pi Zero W and a couple of 1 wire digital thermometers and put together a Fridge monitoring system in a couple of hours. I can now see what happens with my fridge. It does a defrost sequence and comes out of it cold, freezing up the fridge.

I made my own ‘flat’ wires from some old phone wire and electrical tape. This allows the doors to still close and seal around the wires.
With the Raspberry Pi hiding underneath this ‘hat’ or ‘bonnet’ circuit board, the electronics doesn’t look like much. A pair of one wire (really 3) temperature probes and a pull-up resistor. Crazy simple.

A quick dashboard configuration, and I now have a view of the current temperature and a graph of the temperature history.

Hey, something changed! I removed a beverage allowing the cold air from the freezer to hit the temperature probe directly and show a wider temperature swing.

Add a couple of more nodes and I now get email notifications when the fridge is too cold. Another node, and the Google Home announces the too-cold temperature.

My fridge now complains that it is cold.

How epic is that? Under $20 worth of parts to give my fridge a voice.

1000 posts!

A big milestone, that’s for sure, 1000 posts. Granted, this is cheating a little, as it’s counting the twitter summaries as posts, but still…. 1000 posts! I only have 6 ‘drafts’ that are partially completed, so this post could have come a bit sooner.

I’ve been blogging for over 5 years now. http://mike.creuzer.com/2006/01/blogging-just-a-fad.html
I still have that same computer from way back when (it’s now sitting on top of the fridge in the kitchen – best place ever for a computer). Google Pack has recently been sunsetted. I still use Picasa, but how I get photos into it is totally different, between an eye-fi card and my android phones syncing to it automatically.

I am no longer using blogger, but wordpress now. I’ve written my own wordpress plugin.

With so much changing, so much is still the same. I am still making my own aquarium gear – granted with a bit more to it now with the aquaponics aspect.

1000 posts! Crazy!

What would you want to see me blog about more? Less?.

Canned Goods storage

Just an idea for storing canned goods. I see that rack like they use for the Cambells Soup Selects at my local grocery store, and I want something like that for my kitchen.

The basic idea is that the cans sit stacked up in a rack on their side, and you can put the new cans on top, and you take the oldest can out of the bottom. Just like those fridge soda can despensers.

I know I use a lot of canned corn, tomato soup, and canned fruits, but I think that can of cream of celery soup is about to expire. I would need to make a high and low volume set of can holders.

There would be ‘normal’ shelves on the bottom couple of feet for larger canned items like that massive can of baked beans, and the family sized can of cream of mushroom soup. There would be shelf or two up on top for those odd cans like that can of coconut milk – I don’t know why I have it, but it’s good until 2010 so I am keeping it.

The whole thing would be on a tall, narrow drawer that pulls out. I would probably place it next to the fridge, and have it be as deep as the fridge. The cubby that the fridge is in would need to be vented outside – it should be anyhow during the summer, and optionally have it vent into the kitchen during the winter. But that is a different topic for a different day. Heat will damage the food, while canned foods won’t spoil, they will go bad – taste funny, be less nutritious etc. This cabinet will have a couple of computer case fans to pull air in off the floor, and vent it out the top. This should keep the canned goods fairly cool – room temperature at least. Maybe put a thermostat on it so if the temp inside the cabinet is warmer then the intake temp, it will run the fans. I may be cooking and warm the kitchen up enough that it is cooler in the cabinet then in the kitchen. Hmm, I could even run the cold water pipes for the kitchen sink up and down radiator style in the back of the cabinet to keep it cooler. Interesting idea.

Ideally, I would like to cool the whole thing down to like 50 degrees. I wonder if I can canabolize a small fridge and make a cooled pantry. I could hook the thing up on a solar panel on the roof, and when I have sun, it cools, and when I don’t, it doesn’t. It’s not like the cans NEED to be cooled, they will just last a lot longer if they are cool. I read somewhere that food will store twice as long for every 10 degrees cooler it is kept at (or the converse, it will spoil twice as fast for every 10 degrees warmer it is stored at). So bringing the temp from 70 to 50 would quadruple the shelf life of my canned goods.

I am also trying to figure out how do make a can counter so I can tell how many cans of food in a particular slot I have. It would be great to have digital access to this counter so that I can have my pantry make a shopping list for me. It would be internet enabled so I could pull up a list of what i have with my phone, or SMS the pantry asking it what I need to get. A cheap sensor to count cans as I would need dozens of them. Mecanical switches would get very expensive, and be difficult to place to relaibly read any diameter can I put into each rack. Optical switches would probably work. A preasure switch on the face of each slot could measure the weight of all the cans pressing against it. Maybe make a series of metal contacts each hooked up to a resister. I could then read the resistance from one side to the other with a simple R/C timer circut. As more cans are added, the resistance will drop (parallel resistances). I could then have the computer poll each slot, read the resistance, and calculate the number of cans in each slot.