Arduino Freezer Temperature Alarm! Widget108

[@jimafcarbon4433]

One of the big advantages of Arduino projects like this is the ability to change quickly when you have one of the "shoulda woulda coulda" moments after implementation. Agile hardware and software. Thanks for a great example of a starter KISS project.

[@bacawaka2813]

I love those flat wires. It makes electronic projects look so much nicer.

[@stackocakes]

Love to see pride in people's work no matter how simple the project is. Keep up the good work!

[@ZakkBlog]

love having arduino pro minis around for little things like this! Thumbs up as always!

[@RobiSydney]

I buy the ebay nanos with the micro usb connector. I'm also loving the attiny85 digispark board as well -- those are what I'm using in the goggles.

[@GeofDumas]

For flat wire solutions, copper tape between Kapton tape works great. I used to retail a few things on eBay and never actually finished up the last of the stock. Looks like this setup works great with what you've got buy if you need some I'll send a roll of copper tape over free

[@willywgb]

Hi John Great job. Here are a couple of things I would change with your project. A) Add hysteresis to the code to stop Led from cycling at the trip temperature. B) Move the Led to a different pin other than thirteen. The board Led is also powered with pin thirteen. Currant draw for both Leds could be approaching limit of pin. C) Add currant limiting resister to Led. D) Add a Piezo Buzzer for audible warning. Don't always have to be watching the Led. These are just some suggestions to improve your Freezer Warning design. Cheers Willy

[@brianhuff3075]

Great idea using the buzzer! I actually need to make a device such as this for my deep freeze located in my basement. Last year my wife and I had to throw out close to 400 USD of goods. I need to get with the times learn this new fangled Arduino mumbo jumbo!

[@nesuser2]

so....I know I'm late to this. But add a delay in the buzzer and possibly even the light. Connect to wifi and send an alert but again...wait a little bit before alerting, especially based on the quickness it was tripping the sensor.

[@philbx1]

Great to see you having an electronics 'break' John! Trying not to be a smartass here, but maybe 2 suggestions - still keeping it simple (and quiet). 1. Move the blue LED to another digital output (with 180ohm resistor) as it shares the onboard D13 LED and may be pushing the current limit of the pin. 2. Add a high intensity LED to another pin and flash it if over-temp. This would be helped with another global variable ie. volatile int curr_state; so you can control flashing within loop(). Like 'switch (curr_state)...'

[@ingmarm8858]

My thought exactly, where's the current limiting resistor for the LED. Yeah it "works" without it but it's really poor design practice and risks damaging the output stage of the AVR on the Arduino board.

[@jason9375]

And a CNC?? come on, a dremel would have done the job :P lol!! but hey if you have the toys, Play with them just ribbing you!

[@thomasjake3920]

Cool project! (Sorta sorry, bad pun) I agree with the other suggestions an audible alarm and blinking light. Also curious if 32 is a good set point, I think some product will already be thawed by the time you see the mid to high 20's.

[@colinhabursky9037]

Thanks I changed the code a little bit and used this in my hot shed to turn on a relay controlling a fan when it gets hot in my shed

[@dontes9588]

If you add a latch to the code the light will turn On or Off once. So AlarmTemp = 33. and (AlarmTemp-2) = 31, then the light goes off at 33 and then comes on at 31. No bouncing. Code--> else if(fahrenheittemp resistor in series with the LED to limit the current to 17 mA or < (Based on the LED link). Great project. Real simple.

[@koloec94]

Why not solder the connections instead of jumpers? And you should maybe look at a esp8266 so you can get notified anywhere if the is a issue

[@jaywalt1311]

I really need to get a couple of those nanos. I like the project but totally disagree with using breadboard as a permanant "pcb".

[@jaywalt1311]

+NYC CNC protoboard is much cheaper. Also breadboards do not provide much connection strength. Soldering is much more reliable but I guess if anything fails then the LED will go out. Maybe its because I've never seen breadboard used in a long term project. I guess if it works. I really need to get some nanos. Ive only ever used PICs but the nanos look nice and use a standard usb cable. Non of that "add two resistors to a few pins and connect via a serial cable" (getting harder to find pcs with them anyways) rubbish. Is the programming language similar to PICs?

[@RobiSydney]

Arduino uses a C type syntax. I believe PICs had a more BASIC looking language? I buy those nano's 10 or 20 at a time from ebay for like $2.25 each. And the attiny85 for $1.70 w/ MicroUSB. Nano's have 13 digital and 5 analog pins. ATTINY has 6 pins, some which do PWM, or Analog.

[@castro1780]

I don't know why people are hating on arduinos so much. As a more mechanical person, it's great for dabbling in electronics and automation to get down the road to more advanced things.

[@TheRiverHiker]

Great project! I have a shallow well pump about 5 feet under ground and would like to monitor if my temperature drops below, say, 36 degrees Fahrenheit in the winter so I will know if my pump is in danger of freezing. I'm hoping to take this same idea and use it in reverse. Any idea how long the lead on the sensor can be? Thanks again.

[@shootgp]

As always, love the channel. If this was my project, I would of written it a little differently so the LED pulsed and in the case of an error, the LED would blink rapidly. Code wise, something like this... int AlarmTemp = 38; // this is the temperature (in fahrenheit) to trip the LED int PinForLED = 13; // Send output to LED on this pin void setup() { //Serial.begin(9600); if not sending output, no need. pinMode(PinForLED, OUTPUT); //blue LED is on digital pin variable - PinForLED digitalWrite(PinForLED, HIGH); } void loop() { int rawvoltage= analogRead(0); float volts = rawvoltage/205.0; float celsiustemp = 100.0 * volts - 54; float fahrenheittemp = celsiustemp * 9.0/5.0 + 32.0; // If we have a problem, lets blink the LED rapidly. if(AlarmTemp > fahrenheittemp){ digitalWrite(PinForLED, HIGH); // turn the LED on (HIGH is the voltage level) delay(1000); // wait for a second digitalWrite(PinForLED, LOW); // turn the LED off by making the voltage LOW delay(1000); // wait for a second } // If all is well, lets pulse the LED else if(AlarmTemp

[@886014]

One thing to note with the IR thermometers is the laser dot they put on a point isn't in fact what they're measuring. In fact the field of view of the IR sensor is a MUCH larger cone than that, and it's useful to look up IR Thermometers "field of view" and the "distance to spot", and keep them in mind when using the thermometer. In this video it wouldn't really be measuring the temperature of that sensor at all, and just an average of what it saw in the spot; in this case mainly the ambient surfaces. As it turned out they were likely largely the same as the target, but in other situations may not be, and you could be looking for an overheated device.

[@egonsvensson2728]

I would have personally used an ATTiny 85 on a perfboard for the finished product, to shrink it down. Nice that you're coming back to electronics again 👍

[@RobiSydney]

I think I gave him an attiny85. But it's a bear to get working on the arduino IDE! Took me 3 days to get it going on my windows machine. Linux machine it took minutes.

[@egonsvensson2728]

+RobiSydney Yea, they can be a little tricky at first, but after a little research and hard work they're fabolous. And then there is the thing with libraries and compability. 👍

[@Ahmedhkad]

add buzzer is so so simple! with resister you can make a little bit quite (if needed)

[@gunracksonline]

Had the same issue didn't use a Arduino,(haven't messed with one yet eventually I will) i used a Digital Temperature Controller that turns a night light on and it displays the temp.. I keep my freezer at recommended freezer temp 0 degree F. I might of missed understood you but are you setting yours at 32F?

[@szki272]

Put some white duct tape over the knob it isn't very noticeable and will keep it from getting bumped. It can also be used to hold/ hide your sensor wires. We used it alot at work because people don't associate a white stripe or border with duct tape.

[@MikeyFirst]

The decal is a great finish!

[@wvpolekat]

I have a Raspberry Pi monitoring the temp of my son's turtle tank and controlling the heater and lights. It even downloads the sunrise and sunset times so it's in sync with the sun. I can view temp graphs over time, heater duty cycle and even control the lights and heat remotely if needed. Probably more than needed for a freezer though.

[@vitormhenrique]

Whats up John! Love your channel! You could just sample the temperature on a lower rate, like, every minute or 30 seconds, it would not get in the way of letting you know if the freezer got turned of and would probably fix the issue of the light flicking because the temperature would be stable already:)

[@ethanmye-rs]

If you want to build the same device for less than 50c, consider doing it with a comparator, lm35/36, and a few offset resistors. Technically a little more difficult, but a much better way to show off your design chops. If analog isn't your thing, try a DS18B20. Easily available in a waterproof housing, about a buck.

[@giuliobuccini208]

Awesome! From where arduino gets the 5V (or 3.3V) power when mounted close to the refrigerator???

[@johngalt9262]

I'd like to acknowledge that you took it upon yourself to do something, and created something, but did you take any measures to prevent the occurrence from happening again? that would/should have been step 1. (example: caused a fire, so lets put in a smoke detector... instead of addressing the actual problem.)

[@tntodorov]

Hi John, that was a cool idea. When you are sitting at home wondering what to do while you wait for the new baby to wake up, you might want to use the time to add a 2 digit 7 segment indicator for the temp as well - the project box has the space and the nano has the free pins... Or switch from the nano to one of the ESP8266 variants with more pins, like ESP8266-12 and both show and LED indication, but also send yourself and your wife an email when the temp goes too high.

[@royreynolds108]

I think most people consider 32 degrees to be too high. Most freezers are set for 0 F therefore if you would set the alarm at say 10 degrees you probably wouldn't loose any food. At 32 F you probably have lost your food. Most refrigerators and freezers will keep for about 3 days if unopened. Just my thoughts.

[@lmccleary411]

adafruit has those flat ribbon jumper wires that are colored in the order of the resistor color code. so that you can use them and connect them to the arduino and have the wires coordinate to the pins that have the same value as the resistor color chart. very useful when you cant see the silk screening on some breakout boards.

[@EddieSchirmer]

do you think it would be possible to make an aluminum type cap for an electric weed trimmer, with something other than tabs to connect it, and more like screws that would secure it to the barrel that contains the trimmer wire... it would be great to have something that lasted longer than a couple months but still could work as intended... as in, it dispenses wire with a tap to the ground... but something far more durable than the plastic used... and yet light enough not to over load the motor...

[@bcbloc02]

Cool project, literally! I think I would have gone with an alarm to tell me when things were bad rather than a light that tells me things are good but that is just my preference. Probably habit from years of running equipment and watching for warning lights.

[@bcbloc02]

NYC CNC Good point about the power source, a warning does no good if it can not be issued. Paying attention is all about the habits so a light on is just as good as a light off. I find audible alarms always get my attention the quickest.

[@chadkrause6574]

People are saying to have it blink to get attention, which is a dumb idea. I think you should hook a relay to a live grenade so when it gets too warm, it explodes. The advantage to that is you will get a hole in your wall so you can PHYSICALLY SEE the problem, even if you're in another room!

[@kathyquinlan5922]

Great project ! just one comment on construction, for the sensor in the deep freezer, run hookup wire to the sensor, tin the wire then the legs of the sensor, lay the wire flat parallel to the sensor and reheat. This will produce a nice strong joint (the sensor pin will break at the body before the joint) Then use some small heat shrink to insulate the joints, preferably adhesive lined or use adhesive lined over all the smaller heat shrunk joints up to the body of the device this will give you a moisture resistant joint.

[@stuarthardy4626]

John Great info Get some gaffer tape over that temp controller knob , just to make sure Stuart G8OSK G4IJX station now dismantled as has been said its a hobby that grows like Topsy Nearly as expensive as a workshop for hobby use you always need the extra bit of machinery you know how it goes Stuart 73's

[@MatteoGalet]

Hey John, nice and simple project! To avoid the LED bouncing back and forth, try adding some hysteresis to the code: if (temp > alarmTemp + 1) ledOn(); else if (temp < alarmTemp - 1) ledOff(); this is pseudo-code, but you got what I mean ;)

[@cavemansmancave9025]

I suggest you make it flash to get your attention when there's a problem. A flashing light will get your attention quicker. Human eyes are drawn to action and movements. Thanks, John

[@beargun42]

+NYC CNC I think John meant steady on if it's okay; flash if the temperature is too high (and off if there is no power or a connection error).

[@TheSkronk]

If the Arduino hangs (yes it's possible), I guess the LED will stay lit even if the temperature rises above the set temperature level. Flashing will not continue if it hangs, it will probably be either lit or turned off depending on where in the cycle it hangs. So I should have made the LED flash if everything is OK, and turn off if temperature rises too much.

[@cavemansmancave9025]

+NYC CNC Ok, got it. Thanks, John

[@piorism]

Hi - I think that's okay to an extent, but it will probably feel much more satisfying (and reassuring) if the behavior was : steady blue light when everything is fine (blue = good = cold freezer) / flashing red light when there is an issue. That way not only you and your wife but also anyone not familiar with the alarm device will be able to tell if something wrong is going on. ("I walked past your freezer, and a red light was blinking!"). Basically : making sure that the alarm can be understood even without prior briefing or explanations. I hope that makes sense !

[@cavemansmancave9025]

+NYC CNC Sorry, John. I didn't mean to start something. 😊 Pior O is saying what I was trying to say. However, you have the system working to your satisfaction so leave it as is unless you find it to be inadequate. In that case, here are our suggestions. I hope everything goes well with the baby watch. Thanks, John

[@kiloohm]

I think an audible buzzer would be more effective and use less energy. Also, the arduino can be configured so its not always on, you could have it poll once an hour.

[@aemt1131]

Have you thought of making you own printed circuit boards for more permanent projects?

[@russeljacobson2307]

John You need to install a cover plate over the receptacle behind the freezer

[@RoboCNCnl]

Great to see you back on the arduino buddy... I just did a simple and usefull project on it to.... I never hear the doorbell when i'm machining (and as a side note I hate it when people use the bell more then ones...) So I used an arduino to ring the bell for 1 second, flash a blue alarm light in my workshop and disale the bell for 10 seconds... love projects like these... :) cool breadboard in the box this way ! (mine is not haha)

[@Foghorn436]

Just needs a Piezo buzzer and resistor and you could add sound! Use the tone() function..

[@beargun42]

Nice project. I'd put some tape over the dial, so you're less likely to accidentally change it again.

[@belair_boy6035]

If you have a power failure when you are away and the food spoils but the power returns, the LED will come back on and you will be non the wiser. The LED needs to remain off if the temperature rises and then goes low again or could flash indicating that there was a period of time when the freezer was not at the correct temperature.

[@andrecastro7730]

Hello John! Why don't make another video where you add a buzzer?

[@glen4cindy]

This is really awesome. I have a freezer in my basement and in my garage. I have a wireless temperature sensor in both and a display in my livingroom. I really want to add one that is wifi that would send an alert if the temp goes too high.

[@amcdawes]

Clever to only peel off some of the sticky-back! I'll definitely use that, I'm always conflicted about how permanent the sticky-foam seems... compared to the temporary nature of a breadboard :-)

[@petermoore9504]

Does the led have a built in dropper resistor. if not you need a 10k resistor in series with the led to stop it burning out.

[@TheSkronk]

I was thinking the same thing...

[@beargun42]

10k is a bit much. 200 ohm will more than high enough.

[@petermoore9504]

+beargun42 yes youre right 220ohm is a better value

[@jasonwilliams6771]

try putting a LCD screen to show temp readings and also put error report program on it and put it in conjunction with the LCD screen!!!

[@jasonwilliams6771]

good job keep up the good work!!!!!! love ur videos

[@justinmoritz6543]

Oh gosh!!!! Those glasses holy crap!!

[@nailedart4431]

First time I see idea using breadboard permanently in a enclosure, great that fits if you are to change your project easily to something else. Great to see you John doing automation, something you love. I love it too.

[@PilotGT]

Great video - thanks for posting. One thought for "Version 2" would be to use an Adafruit Hazzah ESP8266 board and then it could send a txt when an over temp alarm occurred.

[@aharry63]

I would use a ESP8266 module. They are dirt cheap, can be programmed through the Arduino IDE that you are familiar with, and then it can email you if your temperature falls out of range!

[@cobrabuilder9336]

Suggestion, blink the light on over temp. it will draw attention to itself... and an audible alarm would be nice too. ;-)

[@Hirudin]

Good idea!

[@cobrabuilder9336]

By the way, you have a great idea and are keeping it simple. just suggestions for V2.0. The no light condition would signify no power, blinking error state, alarm would be audible as long as there is power OR a simple relay that would sound the alarm off of a battery in a power fail, solid light all is well. gust energise an output to a simple relay for the alarm the battery would get used when the sensor goes high or the main power fails. I know this is complicating it, you could even use a supercap as the backup power source.

[@rm.throws]

nice project! it's nice when Arduino projects solve real world problems. but you might want to add a resistor between the Nano and the LED. unregulated, the LED will draw 40 milliamps from the Nano digital pin and if that's a normal LED that likes operating in the 15-20 milliamp range it will burn out fairly quickly. that won't be a huge problem since your LED turning off indicates a problem but you might want to limit the current to avoid changing the light so frequently. a 220-330 Ohm resistor should do the trick.

[@Hirudin]

Cool project! Just put the breadboard right in the box, I love it. I'm guessing you may have already done this, but you might want to set the trigger temperature to something a lot lower than 32ºF. My freezer stays at -2ºF and I'm guessing that deep freeze is the same (or maybe even lower). I think I would want to know if my freezer ever got above... I don't know... 10ºF. By the way, refrigerators get down to nearly freezing. Mine stays at 38ºF.

[@Hirudin]

Heheh :)

[@Regalmetalworks]

I know for me, if the light was out, I would never notice it being out until it was probably too late. I would rather have it off, until the temp rose, then light on. Better yet for myself and wife, put a piezo on it and have it scream so you can hear it from inside the house. Great video!

[@DOCDARKNESSREAL]

Great Project. So happy to see you messing about with an Arduino again. Great stuff and good luck on the upcoming baby - Arduino based auto rocker for the crib maybe?

[@KenToonz]

Just think, if you weren't such an Arduino fan you could have just built a little box to cover that silly temperature dial to prevent accidental bumping. :)

[@devastator1488]

That's nice to see you building up electronics projects! I just got Arduions, sensors and wires.. I'll keep watching and going to do the same myself! I wish all the best!

[@mattcurry29]

Very cool, looking forward to more on the Arduino stuff. Matt C

[@ovalwingnut]

Great video. Just what I wanted but I had to stop at the USB cutout step as I don't have a CNC mill. My dad said "maybe some day, son"...

[@dapoopta]

Thank you! Going to hook up a buzzer and light to mine.

[@GregsGarage]

Looking forward to all the arduino projects that will be coming up.

[@JZL003]

I know this is meant to be a project and it illustrates the electronics. But couldn't you just duct tape the dial so it wouldn't move

[@randomstranger9674]

Add a piezo buzzer for the alarm condition?

[@themaconeau]

You can add a small piezo buzzer for both audible and visual confirmation. After a while, you will *think* the light is on, but won't be. As some have suggested, a rapid flashing LED to indicate an error condition would also work too. The Tormach 440 is a nice touch, never could get those holes perfect :P Hot glue is *always* your friend ;)

[@ronkloiber]

I would add a blinking RED Led when temp goes high, as well as a buzzer alarm and Wifi text messaging to my phone.

[@davidmacglashan4206]

If you program some hysteresis into the temp set points the bounce will go away.

[@devjock]

Hahaaa brilliant. Welcome back on the duino-train dude, that was a cool project!

[@RambozoClown]

Cool project ;) I also would make it flash, as if the arduino crashes with the output high, you would never know. Flashing will let you know the code is running.

[@beargun42]

+NYC CNC the Arduino has a watchdog timer to prevent this. It will reset the atmega if the timer runs out. In your code you reset this timer e.g. every loop, so it only runs out if your code isn't running or taking too long. Personally I'd just fade the led in and out very slowly. That way you can detect hanging code, but it isn't that distracting.

[@protoserge]

Good project. Glad you have the electronics bench back up!

[@henninb]

Great video, I plan to do the however I will use an esp8266 or an esp32 microcontroller. I will send an email to myself on higher temps. I believe the quote issue you had during copy and paste was do to microsoft smart quotes. Again great video!

[@waltkiefer9334]

I did not read all the comments so I am taking a chance that someone else made this observation, with that said. The Led should flash when the sensor is within optimal temperature range. Why? If you have a power failure obviously the light will be out, however if you have a system failure of software or hardware the light will go steady state, off or on, thus indicating a fault condition. I use the cheap little boards for all kinds of quick and dirty circuits and had only one crater. Any Who, my 2 cents.

[@jeetsaini143]

No dought bro... U made an awasome project... But I am sorry to say that In market digital thermostat already easily available with led display and setting microswitch only 5$. Sorry

[@rusbrads]

Will this restart automatically after a power interruption?

[@ArcAiN6]

Why not add a small piezo buzzer and now you also have an audible alarm as well as LED, because let's face it, after a couple of months it may slip your mind to pay attention to that LED.

[@jfpinkston1]

Nice video! Great idea Rad!....haven't heard that one in a while.

[@Taluvian]

Add WiFi and code it to email if the temp drops below a certain point.

[@gilaraujo]

Would it be possible to make it emit a annoying sound too? :D

[@ts7113]

Love the Arduino projects!!!

[@SpeedrunnerG55]

also why not install a piezoelectric buzzer so its more noticable

[@SoundsFantastic]

Should of got the model that has the temp alarm built into the lid, the buttons are on top by the lift handle.

[@KK10155]

I'd mount it on the freezer itself, would tidy up the wires too make it nicer :)

[@jjlb82]

nice little project. I'm just getting in to arduino. Did you consider addind a buzzer for failure as well?

[@jeromevuarand3768]

Your second "if" (after the "else") is totally unnecessary, as farenheittemp cannot be >alarmTemp and

[@jeromevuarand3768]

Just to be clear, I was talking about the if condition (between parenthesis), not the if block (between curly braces). Your code is strictly equivalent to this: if (farenheittemp > AlarmTemp) { digitalWrite(13, LOW); } else { digitalWrite(13, HIGH); } And you can also write it like that: digitalWrite(13, farenheittemp > AlarmTemp ? LOW : HIGH);

[@egonsvensson2728]

You should definitely add a buzzer 👍

[@mzlittle]

It was fun to see NYCNC on my first google results for this. I think we need the sensor to page our phones because we will be in the shop when this happens! lol

[@63256325N]

That's a cool setup but I think you need to kid proof it for sure.

[@notsofresh8563]

I would also put some duct tape on the temp control of the freezer so it is not so easy to turn inadvertently. Set it, tape it and forget it.

[@joshuadavis6676]

Why does the arduino nano not fit on the breadboard?

[@paulrautenbach]

Nice easy project.

[@bradycsummers]

fantastic, this is an amazing project. thank you for putting the links

[@donovanpl]

Oh, you're out making cool stuff with your CNC and arduino, while your wife looking after the meals, the kid and the one in the oven?

[@SpeedrunnerG55]

why not make a custom pcb with a mill?

[@DJAndomor]

How to make the same... but with loud buzzer so can check the temp of servers or anythink else.. :)

[@djamalsaou7468]

how hard is it for you to post the code?

[@k5at]

Thumbs up! Great project.

[@larrypardi9143]

When you cut and paste from websites, it can help to cut and paste it into notepad (windows) then cut and paste that into your sketch. Most of the time it works to get rid of non ASCII characters.

[@weshowe51]

I just kept thinking if an electrician watched you wiring up that LED, they would cringe, 'cause they all know "black is hot and white is not". :)

[@schwartzenheimer1]

Better to concentrate on fundamentals, as in current limiting the LED, adding hysteresis at the set point, and other useful design features. Never hurts to do it right, or at least learn how to...