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How SREs Solve Problems at Home (Making my Dumb Fridge Smart) 07 Mar 2021 Pretext This is a story partially about laziness but the weird kind of laziness where, instead of doing the thing, you decide to do something completely different and more convoluted that ends up taking way more time because you can’t be bothered to do the thing. In this instance, the thing is fixing my fridge (though I would argue it shouldn’t be my responsibility to do that, I rent and my landlord should have fixed this when it became an issue months ago but oh well). My Fridge is Broken My fridge, being manufactured in 2003, is old enough to vote. I learned that my fridge was broken by opening the attached freezer on top and looking at a puddle in my ice bin. While this was a useful signal to notice something was wrong with my fridge, I didn’t know what was wrong or how I could fix it. Chatting with my landlord, he mentioned “the previous tenant had a similar issue and whenever it happened, they would cut power to the fridge and wait about 15 minutes and then turn it back on”. For context, the freezer and fridge share a compressor in models like this: Well, at least now I had a remediation step to take, so I gave it a shot and don’t you know, it worked perfectly! Problem solved! …Not really though, unless I want to be checking on my ice bin hourly to know if I needed to power cycle it, I needed another solution. At this point a normal person might consider trying to repair the fridge or hiring someone to do as much, but it’s been over a month since the fridge technician made his house call and there has been no follow-up while the issue persists. So I hopped on amazon and started to solve the problem the only way I know how: with metrics and automated remediation! The Metric For this problem, there are several metrics we could consider. Initially, my metric was looking in the ice bin to see if it was melting (if it was, this would lead to it all refreezing once the compressor started up again turning my cubes into a giant chunk of ice). While this metric works well for me (a human) it also catches the problem too late (the ice has already begun to melt meaning the freezer is over 32F) and it is harder to measure with a computer (maybe a trained computer vision model could learn to see melting ice differently from non-melting ice but that’s a bit more than I signed up for). The solution I settled upon was to monitor the temperature inside the freezer with a bluetooth thermometer probe (though another way could be something like monitoring power draw at the wall of the fridge). I picked up the cheap bluetooth thermometer here for around $15 and set to work installing the app and checking it regularly. This let me observe temperatures that the freezer oscillates between during normal operation and what it looks like when the temperature begins to run away: As you can see, the temperature sits somewhere from 2.5F to 12F regularly and occasionally spikes during weird events. Clearly in the image shown the spike was halted by the system I’m about to build in this blog. So we have a metric and graph viewable in an app. Let’s grab some random FOSS project that can talk to these weird thermometers over bluetooth and slap in in a Raspberry Pi. Gathering Data To interface with the thermometer, instead of using the weird limited app I wondered if someone else had taken a crack at talking to this device directly and it turns out they did! I found a project called Inkbird and forked it to twist to my nefarious purposes of making my fridge smart. In a nutshell, this is a node.js project that utilizes the noble BLE module to talk to Inkbird thermometers. Though this code was written for a previous version, so I had to modify one of the constants to scan BLE devices and filter for the correct device name. I found the right name through experimenting with a bluetooth scanning app on my phone and opening and closing the freezer door to see which device jumped in signal when it opened. I wrote a loop that connects to the thermometer once a minute to avoid killing its battery prematurely. It grabs one datapoint containing a temperature and battery level reading and then disconnects. It then exposes the program state via a JSON API endpoint with Express. An abbreviated form of the final product can be found below: const IBS_TH1 = require("./ibs_th1"); const log4js = require("log4js"); const logger_ = log4js.getLogger(); logger_.level = "info"; const device = new IBS_TH1(); let state = { connecting: false, gotData: false, waitCount: 60, //... }; let sensorState = { temps: [], battery: 0, lastUpdated: new Date().toString("en-US"), }; const callback = (data) => { logger_.debug( `Current Temp: ${data.temperature.toFixed(2)}°F -` + ` Battery: ${data.battery}%` ); sensorState.battery = data.battery; if (sensorState.temps.length > 60) { sensorState.temps.shift(); } sensorState.temps.push(data.temperature.toFixed(3)); sensorState.lastUpdated = new Date().toString("en-US"); state.gotData = true; device.unsubscribeRealtimeData(); logger_.debug("Disconnecting from sensor"); }; const dutyLoop = function () { //... if (!state.connecting && state.waitCount >= 60) { device.subscribeRealtimeData(callback); logger_.debug("Connecting to sensor"); state.connecting = true; } else if (!state.connecting) { state.waitCount++; } else { if (state.gotData) { state.gotData = false; state.waitCount = 0; state.connecting = false; } } }; logger_.info("Starting duty loop..."); setInterval(dutyLoop, 1000); Metric Monitoring and Heuristics This code as written will build a running log of the past 60 minutes of one-per-minute measurements of freezer temperature, and track the current battery life of the sensor. To enhance it we want to add some kind of heuristic to determine if the freezer is too warm. We can do that by setting a trigger temperature and then a number of minutes the freezer must be above that temperature to trigger the alarm. We also want to add an alarm cooldown so we don’t trigger once a minute while the freezer temp is rising. Since even if we kick in remediation it can take some time to drop the temps back down. So we’ll add these variables to state: let state = { //... triggerTemp: 20, triggerMinutes: 5, lastPowerReset: new Date(0), cooldownMin: 60, powerCycleWaitTime: 15, } Nice, now we want to add the heuristic to our loop by grabbing the last triggerMinutes worth of measurements from sensorState.temps and checking if all of them are over the triggerTemp. const dutyLoop = function(){ // Evaluate state const now = new Date(); if (now - state.lastPowerReset > state.cooldownMin * 60000) { if ( sensorState.temps .slice(-state.triggerMinutes) .filter((temp) => temp > state.triggerTemp).length >= state.triggerMinutes ) { logger_.info( `Freezer has been over trigger temp of (${state.triggerTemp}F) for at least (${state.triggerMinutes}) minutes.` ); if (now - state.lastPowerReset > state.triggerMinutes * 60000) { logger_.info( `Resetting fridge power, last reset was at (${state.lastPowerReset.toLocaleString( "en-US" )})` ); state.lastPowerReset = now; // Remediate the problem... } } } //... } Finally, we need to somehow remediate the problem. Automated Remediation We know that powering the fridge off and waiting about 15 minutes and turning it back on seems to remediate the issue. Do I know why that works? No. Do I need to know in order to fix it? Also no. But we can simply automate the power cycling to make this problem fix itself. All I need to do is power off the fridge, wait 15 minutes, and turn it on, but from code. As a bit of background I wrote this home automation API in Go a couple months ago which talks to Philips Hue, Belkin WeMo, and Tasmota IOT devices through different protocols and gives me the ability to control them at will and with automation. The interesting bits for this project are the SetStateHandler which can be found here. This code allows me to set the power state of a given Tasmota outlet connected to a MQTT broker in my apartment. I hacked up some old Gosund ESP8266 based WiFi Smart Plugs and installed Tasmota on them with the aid of TuyaConvert which allows you to OverTheAir upgrade some off-the-shelf IOT devices. It is worth knowing that some of the recent Gosund units I’ve bought from Amazon have updated firmware that is harder to flash and until recently I wasn’t able to update them until the TuyaConvert project managed to crack some of their newer security features for OTA updates. So we have an API in my home that allows me to talk to an outlet and make it turn on and off, so the last thing to do is integrate it into the temperature tracking code. We’ll use Axios to make a JSON POST request to the API as required. const axios = require("axios"); const setFridgeState = function (desiredState) { axios .post(process.env.OUTLET_URL, { apiKey: process.env.OUTLET_API_KEY, device: process.env.OUTLET_DEVICE_NAME, powerState: desiredState, }) .then((res) => { logger_.info( `Successfully set fridge to state (${desiredState}): `, res.data ); }) .catch((err) => { logger_.error(`Failed to set fridge to state (${desiredState}): `, err); }); }; Now we can invoke the setFridgeState function from our heuristic code to turn off the fridge and use the powerCycleWaitTime variable to tell it how long to wait before turning the fridge back on. const dutyLoop = function(){ //... // Remediate the problem... state.lastPowerReset = now; setFridgeState("off"); setTimeout(() => { logger_.info( `Powering fridge back on after (${state.powerCycleWaitTime}) minutes...` ); setFridgeState("on"); }, state.powerCycleWaitTime * 60000); //... } Conclusion We now have a system that detects when the metric is over a threshold for a specified period of time, triggers a remediation step to bring the metric back under the threshold, and then cools down before trying to remediate again. Or in normal terms: if the freezer is getting too warm we turn the fridge off and wait 15 minutes and turn it back on. But we don’t try this more than once in an hour to let the compressor do its work. The full source code can be found here, but I hope nobody is in a situation where you have to use it. This was a fun project that let me use tools from the SRE toolbox to solve an everyday problem and the best part is that it actually works! The compressor didn’t turn on last night around 1:30 AM and the system recognized it before the freezer got to 30F and corrected it without any weird bugs! I now no longer have to worry about food spoiling in the fridge overnight because the fridge forgot to cool things. One more thing I might consider adding to the system is a notification to my email when a remediation attempt is made so I can see if this problem is getting worse or if there might be an issue with the code if it tries to remediate at high frequency. Please note that all of this code for this project is really just duct taped together to fix my fridge and not representative of the code I typically write on “important” projects. The gohome code is a bit more polished so go look at that instead. The total Bill of Materials for the project was around $50 including one Gosund outlet, one Raspberry Pi 3B+, and one Inkbird IBS-TH2. That’s all folks, thanks for reading. Eric V Note: The contents of this post are from my blog and have been copied to fit this forum page.

Listen Linus, I have an idea, one that i think youll like. One thats gonna make you rich. Now listen closely cause your gonna wanna hear this. This, will be, life changing. And thats an understatement. What if a cooling component didnt have to be a fan or water cooling. What if, it was, the case. Now listen theres something me and my colleagues have built which can bring all interior components down to freezing temperatures. This includes the CPU the GPU and PPU. The only issue is we dont have a platform as big as one such as yours to commercialize it. This would eliminate all down sides of high performance PC components. Were talking about, a full sized, massive, industrial, Mega freezer. Now that might have "spooked" you, a bit. But i know, just like myself, your a visionary. All me and my Colleagues need is $500,000 for 20% of our stock. Remember us, we are the future, we are, Fridge.

Hey guy, so for my art project I wanted to make an R2D2 Fridge, which makes a sound when u open it (R2D2 Scream or something), but Im not really sure how Im supposed to make it make a sound thats why I came here with a few question, just to make sure it would work 1. Am I able to just draw the power from the wall, if i use some sort of adaptor if so, what should I get? 2. Would this work as Im intending it to work? (Pic) 3. What kind of device would I need to make the sound? And can I just disassemble my old speakers and use the cones? Btw, the weird box on the right of the pic is a "devider"

I'm going to be starting my first build and I don't know where I can ground myself. I have no idea where or what materials I can ground myself on besides "metal". I don't know if some things are metal or some things are painted to look metal etc. Anyways here are a few things I want to know if I can ground myself on or not. My fridge: Whirlpool WRT518SZFW Top Freezer Refrigerator My case: NZXT S430 Elite Matte White I got a car too, some pans, I DON'T KNOW ALRIGHT JUST HELP PLEASE please give suggestions on how I would go about doing this without a anti-static wrist strap or anti-static mat Thanks everyone for the help!

Ok so I live in an apartment and have a mini fridge in my room. I live here for college and of course as a college student I have to keep my beer close. Never know when you'll need to crack open a cold one with the boys. Anyway when the compressor turns off, one of my monitors turns off and my speakers pop. In my previous dorm each side of the room had it's own circuit, but that is not the case in this apartment. Since it happens when the compressor turns off, it's not a brown out, it's a spike. I don't want this to kill any of my expensive computer parts, so I am trying to find something to isolate the fridge from the computer. All of my computer power goes through one surge protector. The monitors, speakers, and the computer. From what I read online a double conversion UPS would be exactly what I need. But they start at like $800. Way outside my budget. Another option is a line conditioner with voltage regulation. I have read conflicting opinions on whether or not this will help, but seem like it could be a solid option. The last option I have found is a isolation transformer. This is something that I would plug the fridge into to hopefully isolate it from the rest of the circuit. But again not really sure it would actually help. Anyone who has experience with this, any advice on how you solved it or attempted to solve it would be appreciated. I like the idea of isolating the fridge from everything else instead of just protecting my PC from the noise and spikes it produces, I just don't know if it will really work.

CES 2018, LG's new ThinQ Smart Fridge. It comes with a 29" touch screen display that's also has a unique feature. Knock on it twice and the screen become transparent, letting you see what's inside. IMO, I doubt the screen is actually transparent. Knocking it most likely just turns on the camera from inside to make it's transparent. But if it's actually transparent, then that's really cool. http://www.lgnewsroom.com/2018/01/lgs-connected-appliance-network-makes-the-future-kitchen-more-delightful/ https://www.theverge.com/circuitbreaker/2018/1/7/16860260/lg-instaview-thinq-smart-refrigerator-webos-alexa-home-ces-2018

Long story short: I got this Frigidaire Retro Mini Fridge that only holds 6 normal sized cans of soda, but is rather portable. I got it last year during a Black Friday sale and it's been pretty good to me... until the cooling fan died. I tore it apart and discovered it's made with some pretty simple components. I've always wanted to get into hobby electronics and I think this would be a good start. I don't want to just replace the fan, I want to upgrade the machine so it gets colder. Is there anyone who can help me, or at least point me to some good resources so I can learn by myself? Long story long: This is a relatively simple machine. It's small, compact, lightweight, comes with a handle for easy carrying, and even has a port for a cigarette lighter in a car. This thing is made to run off of 12v car batteries, so again, a pretty simple machine. Here are the internal components themselves in their entirety: The fridge contains 3 main things: A 3cm square Peltier cooling unit (left) An 8x8x2cm fan (upper center) A circuit board with a whack ton of heatsinks and capacitors. (right) I didn't know about Peltier cooling units when I opened this thing up, and I thought that little white square was black magic. Coincidentally enough, Linus Tech Tips uploaded a video where they used Peltier's to cool a PC, to some degree. Basically they move electrons from one side of the unit to the other. Moving the energy away from one side causes that side to get cold and the other side to get hot. While it's not great for large scale cooling, it's great for small scale applications like this. The fridge actually gets decently cold too. Of course, as you can see the Peltier unit is connected to a FAT heatsink (2 actually, the second isn't pictured but it's a solid 3.6x.3.6x2cm metal block and the unit is sandwiched between them) and on the other side of that heatsink is the fan, which of course points to the back of the fridge. To my understanding, if I wanted to upgrade the cooling capacity of this fridge, I would need either a bigger or more powerful Peltier unit, or maybe give the current one more power, of course I would need a bigger fan to carry more heat, and then maybe remove something from the circuit board so that it can run more power (because the units themselves need more power, otherwise I'm just throttling everything and ruining the point). Again, that is MY understanding of what I would need to do to upgrade this thing, but I am NOT a professional, and I don't know much about electronics, especially custom stuff like this. That's why I turned to the forums. If I were to try and go at this, I'm thinking best case scenario I get no perceptible difference in temperature, most likely scenario I would brick the fridge and have to throw it out, worst case scenario I burn my house down. I want as much help as people are willing to give me because I wanna make sure I get this right.

Linus made a video where he brings the PC to the fridge. But what if you take the fridge and bring it to the PC? Granted, the side of the machine would be incredibly hot, but the interior could potentially make it good for OC-ing. Maybe. What do you fellas think?

At LTT when it comes to Samsung, we think of their smart phones, laptops, and SSD. But did you know they make other things too. At this year's CES, they introduced a brand new smart fridge that's different from their previous models. Unlike their previous one that sports a puny 8 inch screen, this new one features a gigantic 21.5 inch touch screen, with built in proximity sensor that lights up the screen where your near it. It that can also stream music from the built in Pandora app, set food reminder list, sync family schedules, and even order food with the Mastercard groceries app. The fridge has a 4 door design that's similar to their Chef Collection model, where the upper right side features their CoolSelect+ that can convert that section as a freezer or fridge. It even has a built in cameras where it will take a snapshot of what's in the fridge every time you close the door. So you'll be able to see what else you need to buy, with the Samsung fridge app right on your Android or iOS device. Samsung is also planning to incorporate Amazon's Alexa cloud based AI with this smart fridge so you can directly communicate with it, much like their Amazon Echo smart speaker. It's schedule to launch Spring of this year but Amazon's Alexa might come later on down the road. Cost of fridge? $5,000 dollars. http://www.cnet.com/products/samsung-family-hub-refrigerator/

Amazon: http://geni.us/3mVW NCIX: n/a I'm sure we've ALL thought of doing this to a PC at some point. But is building a computer in a mini fridge ACTUALLY worth the effort? Vessel link: https://www.vessel.com/videos/Grw7CMTcm YouTube link:

This isn't a hating thread even if i wanted to just say that they have no life and it isn't good for what are they doing, so i installed windows 8.1 and on metro i have news, this is what ive got. ill just quote! "Imagine driving on the freeway at 60 miles per hour and your car suddenly screeches to a halt, causing a pileup that injures dozens of people. Now imagine you had absolutely nothing to do with the accident because your car was taken over by hackers. Charlie Miller, a security researcher at Twitter, and Chris Valasek, director of security intelligence at IOActive, a security research company, recently demonstrated car hacks at the DefCon computer security conferences in Las Vegas. The researchers completely disabled a driver’s ability to control a vehicle. No brakes. Distorted steering. All with a click of a button, while the demos were with hybrid cars, researchers warn that dozens of modern vehicles could be susceptible. Hackers and security researchers are moving away from simply trying to break into — or protect — people’s e-mail accounts, stealing credit cards and other dirty digital deeds. Now they’re exploring vulnerabilities to break through the high-tech security of homes, cause car accidents or in some extreme cases, kill people who use implanted medical devices. “Once any single computer in a car is compromised, safety of the vehicle goes out the window,” Mr. Miller said in an e-mail interview. Modern cars typically have 10 to 40 little computers in them. “Right now, there aren’t a lot of ways for hackers to remotely attack cars: Bluetooth, wireless tire sensors, telematics units,” he added. “But as cars get Internet connections, things will get easier for the attacker.” Carmakers and the government are aware that our vehicles are vulnerable. In fact, Mr. Miller and Mr. Valasek received a grant from the Defense Advanced Research Projects Agency, or Darpa, to research ways carmakers can thwart attacks. The biggest fear is the future: as cars become more computerized — or become fully automated, computers on wheels that drive for you — they’ll become more inviting targets. But the demonstrations by security experts and hackers weren’t a peek at what’s to come. The researchers hacked a Toyota Prius and Ford Escape, two hybrid cars that are already on the road. Certainly, hackable cars are a troubling development for people who don’t even like to use cruise control. Now to add to your paranoia, security researchers warned that our homes are more vulnerable than our cars to attackers. That is, if burglars trade in their lockpicks and crowbars for laptops and Wi-Fi scanners. Devices like the Lockitron, a Wi-Fi enabled front-door lock that can be used with a smartphone, could open a way for technically skilled thieves to break into your home. That’s not to pick on Lockitron. They just happen to be on the cutting-edge of wireless home security. “We’ve built Lockitron from the ground up with security in mind,” the company said in a statement, while acknowledging that “anyone claiming their system is ‘unhackable’ is wrong.” At the conferences, security experts lauded the company for the protection it has built into the Lockitron. Hackers could also turn our televisions and webcams against us, monitoring everything we’re saying and doing. Digital refrigerators could be turned off, allowing food to spoil without your knowledge. Some hacks could be mere practical jokes, albeit messy ones. Researchers have warned that the Bluetooth-enabled INAX Satis model toilets, which can be controlled via a smartphone app, could easily be hacked to spray water up instead of down. In response to warnings that its toilets could be hacked, INAX said it issued a security update for its toilets this month. Yes, in the future, you will need to download security updates for your toilet. And then, there are the usual smartphones fears. At BlackHat, Kevin McNamee, the director of Kindsight Security Labs, demonstrated how to take over an Android smartphone by injecting code through the game “Angry Birds.” Once he had control of the phone, Mr. McNamee was able to remove photos and personal data from the device without the owner having any clue. Other researchers took over an iPhone by hacking a power adapter — yes, a little white power cord — to suck passwords and e-mails from a device that ran operating systems earlier than iOS 7. But some of the most advanced security researchers are thinking about even scarier hacks, of implanted medical devices. Barnaby Jack, who was perhaps best known for a hack that made an A.T.M. spit out cash, was supposed to demonstrate at Black Hat how implantable medical devices, including a pacemaker, can be hacked to kill someone. But Mr. Jack, who was in his 30s, died shortly before he was to make his presentation, of causes that have yet to be determined. He was often referred to as an “ethical hacker” and hoped to show the pacemaker exploit as a warning to device makers. So, should we dig holes in our yards, bury our computers and smartphones and never drive our cars again? Some researchers said many of these demonstrations were provocative, but they were more theoretical than any sort of real risk we had to worry about today. “Sometimes there is a gap between the researcher community and the real world. Researchers bridge this gap often, but it’s not uncommon to see conference talks on exotic technologies that don’t really impact our everyday lives just yet,” said Chris Rohlf, founder of Leaf Security Research, a security consulting company, in an interview. “As technology embeds itself into these everyday devices and other parts of our lives, you will see an increased focus on their security. Anywhere you find technology you’ll inevitably find hackers.” When these technologies do arrive, I would not count on the companies that are installing computers in our cars, homes and bodies to be able to stop rogue hackers. “We haven’t figured out how to stop attacks against Web browsers in personal computers despite trying for the last 10 years, so there isn’t any reason to think that we can stop attacks against cars or other devices in the near future,” Mr. Miller said. “We should be concerned and start taking action now before something bad happens. I’ll still be using my car and refrigerator in the meantime though.” OOOOkkkkkkkkkk, now this is really scary, if there is a post simmilar to this please redirect me but till then, tell me what do you think about this, i don't know why but this reminds me of CarTube video.

Hi guys, New year has come and so have new ideas. I really like building computers, but I don't need another one, so I decided to start modifying my current one and also make my first post on this forum. The idea itself is to get a mini sized "fridge" inside the computer chassis. The fridge idea has been on my mind for a few years and yesterday I finally decided to make it happen. So far what I have thought about it, it would take the space of two 5.25" slots, and it would be cooled by a peltier unit (the idea of the unit https://en.wikipedia.org/wiki/Thermoelectric_effect), which would take its power from a 4-pin molex. The mod isn't a big job, but it will most likely take some time because of the lack of few tools, materials and work space. Still, this time it will be done Feedback is always welcome, and if you have any ideas, let me know. Hardware Specifications: Intel Core i5 4670K Asus TUF Gryphon w/ Armor kit 8GB Kingston HyperX 1600 mhz Asus Geforce GTX 770 DCII 256GB of SSD and 2TB HDD Define Mini Other things: Peltier unit - If I manage to fix a old one, otherwise nope Heatsink for the peltier - Yes. Some kinda... Plexiglass for a window - Yes Something I forgot to mention - Most likely not Sorry about the picture quality... The starting point. The place for the "fridge" The first thing I did was getting rid of those "rails" for the middle hard drive rack. It might sound easy, but when you don't have proper tools.... nope. After some hours of finding the best tool and trying to open the screws, I finally managed to take them off. The next step will be thinking about the placing of the peltier unit. I was thinking about putting it under the 5.25" rack, the same place where the hdd rail was.

i wanted to show off to my friend and overclock my cpu so im on cpu-z i5 760 15# top overclocks. in order to do that i put my pc in a fridge, and turn it on. it turns on for few seconds and then shuts off. after taking the components out of the fridge i notice water all over my motherboard and some on my graphic card. by then i was 99% sure that one or more of my components were dead. i dried out my mobo and gpu for about ~30 minutes and it still works! VIDEO (CLICKY) http://youtu.be/tkBRu43N-IA

Hello. I was wondering if I can put my PC in a fridge to keep it cool. I was thinking to maybe cut special holes for the power and internet wires, then insulating those wires and the area around the hole. Is this a bad idea? Please help