So I’m new and naive but I had a brainstorm the other day after a pan got burnt up on the stove… again.
Older folks like me, have some issues with concentration especially when trying to get a meal together and lots of times trouble starts when a senior leaves a burner on and then sits down for dinner and even perhaps goes and watches tv. Pans get ruined, fires start, people get burned. There are lots of solutions for electric stoves which already have lamps to warn you an element is on but gas stoves have no indicators for the stove top burners.
I’ve seen some offers for gas stoves that incorporate a push button that must be reset or the gas shuts off and I think that is ridiculous and also they cost as much as the stove itself and require someone to install the gas valve.
Blynk to the rescue.
I’m thinking magnetic hi- temp sensors attached to the bottom side of the range pan at each burner area and maybe even one on the top of the oven chamber.
I’m thinking a pir sensor to tell your nodemcu when activity has ceased at the stove
I’m thinking coding a notification via board mounted buzzer that reacts to the proper conditions being met and even an online notification response that you could assign a ringtone to like a fire siren, etc.
So, if you step away from the stove and leave a location of heat running you get warned.
So far I’ve found hi-temp sensors on the arduino store for $8 and I bet they could be had a lot cheaper elsewhere and all the rest of the components are dirt cheap and even a minimal handy person can affix magnets. No plumber, no electrician, no $500 expense
It’s just an idea and it is open for anyone who thinks it would be good for the grandparents or hey maybe make your fortune.
Happy Blynking
It’s actually a very good idea. I’ve seen a similar request on the forum here from a guy in Russia who wanted to check of the stove of his dad or mom was turned on for x-amount of period. They lived like a thousand miles apart, so … you can imagine the use case for something like this, I sure can.
I think there is a big IF (and not in a programmers way). If something went wrong your insurance might go nuts on this with all the hassle belonging to it. There are certain rules and regulations for gas and such and I for one, don’t like to fiddle with those. So there is another aspect here, not only technical (which would be very easy probably), but also some juridical stuff.
Sensing stuff as you described would probably be a good idea though. There are probably sensors (like ones for the BBQ) who can measure a good high temperature. Combined with the PIR it could be a match made in heaven.
The reason those safety stoves are so expensive is, I think, the fact that they are approved by insurers and such.
I wonder, modern gas stoves don’t have any LED indicators?
The units I referred to are not safety stoves, they are add ons that cost as much as the stove itself. As far as insurance goes, we are not cutting into the gas supply, that is the reason the other add ons cost a fortune. The solenoid gas valve alone is over a hundred and then anytime you mess there what you modify must be ansi certified. Good luck with that.
So this idea is perfectly passive, the only issue would be the power supply for the board needing to be UL as well as the sensors. As far as lifting the range pan, it’s part of normal household cleaning. I clean accumulated messes under there once a year because even the modern stoves can get gunk there as a result of accidents/boilovers, etc. Gas range tops are not really “sealed” in any meaningful way.
Nope, never have seen one at any store I shop, Perhaps some high end unit might but spending thousands on a stove isn’t for the 99%.
one of the sensors I found:https://www.adafruit.com/product/3245 $10 probably could be found for $5.
So you got me searching and I did find a $1500 range top only that has dials that light up when they are turned. But I still haven’t found a stove and I looked clear up to $10K.
I for one am not going to buy a new stove to get some led’s even if it were possible. I think I’ll contact NFPI and get their input on passive devices. I look at it like smoke detectors, passive, insurance company’s sometimes give a discount if you have them, but if you don’t and your house burns down they do not refuse coverage. They can’t because detectors were not part of the building code for private residences. Public housing and rentals are completely different, if you owned a rental property and put one on the stove there could perhaps be a problem but one more involving a personal liability due to the renters expected level of safety, but even then it would be a hard sell because they were negligent in the first place leaving the stove on and unattended. I wouldn’t be a landlord for all the tea in China.
I think I’d go down the route of sensing the position of the knobs that control the gas flow to each burner ring. Maybe attaching a small magnet and using a reed switch so that you know when the knobs are in the off position.
Pete.
Pete I like that idea too.
I thought in that direction as well but could not come up with a truly simple implementation due to the very cramped nature of that particular area behind the bezel and the vastly different styles. I was aiming at something totally passive that didn’t involve any modifications to the stove at all because once you put a drill to a stove to mount anything you are in trouble with safety people/insurers. This is why I thought of the magnetic sensors. I’d still like to get a look see at one of those range tops that has the lighted knobs, they must be totally self contained. I’m thinking led array,battery or wireless charging,mercury switch?
The knobs have to be removable and cleanable I would think on a range top costing close to two grand. But who knows.
I appreciate the brainstorming, it’s fun to run through ideas, and the more eyes the better. One idea although not workable may in part lead to another solution.
I’ve thought of IR but rejected that because of the development of the problem, the person cooks in the pan most likely just keeping something like a sauce warm while the spaghetti boils then plates the pasta, grabs the pan of sauce or even leaves it in place while ladling and either leaves the pan there or returns it there forgetting to turn the knob off. I’m not sure an IR detector would pick up a low flame under a large skillet or pot, or be able to differentiate between a still warm pan and an actual heat generator. I’ve done quite a few inquiries with seniors and have found that this is the scenario.
A burner lit with nothing over it is usually spotted and even if it was missed it is at most a burn hazard, unless the below happens.
LOL, my wife once did this leaving the burner on low removing the pan and then without realizing it put the wood cutting board on the range. About a half hour later I’m noticing a haze and a smell of woodsmoke, only after checking the woodstove did I go over to the kitchen to find the smoldering board. We now have a rule about flammables on the range, but even so I have had to remove tea towels and potholders since. Now I do most of the cooking but have to admit to leaving a burner on twice.
One thing I noticed when apartment hunting in Denver is the vast preponderance of electric stoves in corporate managed apartments We’ve had both through the years and I truly hate cooking on electric and I think most who have had gas would not care to switch, and seniors never want to change anything.
I’ll do some searching concerning a magnetic sensor that would change state when another magnetic field is sensed.
With any type of heat sensing there would have to be a delay in the code and then a resample to differentiate a cooling range top vs one still receiving btu’s, and in the scenario I came up with the individual sensors might have to be polled several times before the buzzer went off.
what about buying an induction stove and forget about all the nasty flames, gas, fire hazard, etc?
it is also much more green and energy efficient, with zero potential risk + much easier to clean.
the worst thing what can happen if you forget something on the turned on stove, that you create some smoke and or damage the pan. none of them is big deal, nor comparable to a gas explosion or fire hazard. but lots of models have some built in kill switch which turns it off anyway after x hours.
I’m assuming you mean electric? I appreciate the input but that’s not where the discussion is. There are millions of people out there who are very happy cooking with gas and they deserve to have the same safety indicators or better than those offered to users of electric. And BTW I was recently called to an apartment kitchen fire caused by a senior who left the pot on the induction stove top to the point that not only was there a fire involving the contents but also the aluminum pot melted and ruined the whole stove, fortunately no one was injured. Those folks went to assisted living. This stuff happens every day.
i see your point. but monitoring / automatising electronic stuff is allways much easier than achieving the same level of safety with gas for example.
if these basic safety measures were so easy to implement reliably, probably there would be lots of available gas stoves already on the market with those features.
do not misunderstand me, i’m also fan of diy. but in this area, there is big risk / responsibility involved.
maybe one can create a false “security” feeling (ah, i can stay relaxed, because the mcu will alert me if i forgot to turn off the gas… boom), and if something goes wrong, he won’t have a second chance.
blynk system and all those iot boards are nice for hobby use and even production, but i never ever would rely human life on them! just my 2 cents…
I’ve been thinking on this and the more I do the more I realize that what would be needed would be a ttl sensor for flow to detect the passage of the gas through the line to the individual burner, a wire sensor sort of like a MAF in a car. Still thinking.
As far as Waneks comments regarding safety, I see his point but think he should talk to seniors abt’ how they feel. I NEVER experienced this until after the age of 70, it was a real surprise and not a good one. We cannot always assume someone would have done it already, there’s a lot of areas of elder safety that before the Boomers were never thought of.
But you previously said:
Putting flow sensors in the lines to the individual burners sounds like a higher level of modification than you were previously thinking would be acceptable 
How about the idea of a non-contact temperature sensor such as this:
These have a 35 degree field of view, so to cover a typical 600mm wide hob you’d need to mount it about 1 metre above, so could possibly be incorporated into your PIR detector.
If the PIR hasn’t detected any movement for a certain time then take a reading of the hob temperatures. Take another reading say 1 minute later and if the temperature hasn’t dropped from the first reading then the hob is still on and you can sound your alert.
Pete.
Well I’d like to thank everyone here who made a positive contribution. It seems that a creative young person saw this need as well as posts on this subject across the web, got his brain in gear and solved the problem. He recently brought his product to market and is receiving accolades, fame and, I hope, some fortune. Senior Living communities are excited, AARP is interested and I am waiting for mine to arrive.
Granted his solution is extremely basic but hey if it saves one burnt up stove or even one life it’s a winner. I can foresee safety of this type being implemented across the industry and I’m willing to bet he gets a sweet offer.
I would have loved to have had a more sophisticated solution involving PIR and even remote notification as might be realized through BLYNK, but for now, I’m very happy with his work.
I will keep the thread open if that’s OK
I also have been looking at inexpensive tiny ultrasonic sensors made to fit on the outside of a tube that would detect flow.
I feel that temp is the wrong way to go as it will not sense gas flow that has not seen ignition. This happened the other day when my wife bumped into the stove when we were moving an appliance, neither of us noticed it and went into the livingroom, had I not returned to the kitchen dangerous levels of gas might have been a disaster.
This guys knob attachment would have provided an audible and visual alert.
If we had a BLYNK enabled sensor and went downtown after the bump we could have gotten an alert that could save the house or a person residing in another part of the home.
The possibilities are endless for property and life.
Not sure about recently… some of his videos go back to 2014 
So he is now rich and famous or another unfortunate inventor.
I think the idea of, simpler is better, is the way to go… unless you really have the “burning” urge to know if you left your stove on from across town or the world, an IoT notification of something that can cause relatively quick results (long before you make it to the airport) needs to be more localised and less dependent on WiFi, servers, power, etc.
A simple gas detector should do the trick… they have them in RVs and will detect propane, CO2…
Was fumbling around the internet and ran across THIS. Looks like you can “reserve” one for about $100 USD.
[Off-topic comments and link to unrelated website removed by moderator - again]
@lakersgirl, I have again removed your off-topic comments and a link to a website that is unconnected to the topic being discussed.
This is a technical discussion forum related to the use of Blynk software, not a shopping site for domestic appliances.
I’m not sure if you have a connection to the website in question, but if you persist in this action I will suspend your Blynk community account.
Pete.