Octradox
Posts: 22
Joined: Fri Jun 23, 2017 5:53 pm

Detect heat of stovetop?

Mon Feb 12, 2018 9:29 am

So this is probably a pipe dream due to temperature and stuff but I thought I'd ask in case there are components that can do this or if someone can thing of a creative solution

So basically I'm building kinda like a hud helmet. Guess you could say AR, but its not really augmenting reality but instead telling me things, so more like a HUD. Not critical, but relevant.

Basically I'm trying to think of applications for this and I was thinking cooking (more than just having the helmet block out the crying of onions). Is there any small device that could optimally be relatively small, have some sort of networking capability (bluetooth), battery powered, able to be made waterproof (I guess that's just any case really), and also be able to measure how warm it is, whilst being able to withstand the temperature?

Basically I want to put a device like that in my pots and pans while I cook and have that device relay back to me (on my AR helmet) their temperatures.

Probably not really feasible, but I thought it would be a neat thing to do and am wondering how to go about it? Or if you think I could achieve the goal is a less silly way? Because that device sounds really specific..

PiGraham
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Re: Detect heat of stovetop?

Mon Feb 12, 2018 9:44 am

There are various ways to measure temperature without the sensing device getting hot.
A thermal camera
https://learn.adafruit.com/adafruit-amg ... mal-camera

An Infrared Thermometer
https://www.amazon.co.uk/Thermometer-Ta ... hermometer

A non-contact temperature sensor
https://www.sparkfun.com/products/9570

These all depend on the emissivity of the surface your are measuring. Shiny metal or clear liquid won't read as well as a mat black surface.


You can also get food thermometers designed to be inserted into food and made of food safe materials that can be properly cleaned. Some have wireless connection to a display. Some have Bluetooth and it might be possible to connect to them with Pi3 or Pi0W's onboard Bluetooth. It may be difficult to make that work.

scotty101
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Re: Detect heat of stovetop?

Mon Feb 12, 2018 9:54 am

I've seen non-contact thermometers mounted above a hob before. If I remember correctly the person had used I sensor per 'hob plate' and had some form of LCD display showing the temperature of each object. Could probably be adapted to send data over a wireless protocol.
Electronic and Computer Engineer
Pi Interests: Home Automation, IOT, Python and Tkinter

PiGraham
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Joined: Fri Jun 07, 2013 12:37 pm
Location: Waterlooville

Re: Detect heat of stovetop?

Mon Feb 12, 2018 9:57 am

You could also fit thermocouples under hot plates if it is sufficient to measure the temperature of the plate. Make sure to use a type that is suited to the full range of temperatures the hotplate can reach.

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Burngate
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Re: Detect heat of stovetop?

Mon Feb 12, 2018 11:57 am

Octradox wrote:
Mon Feb 12, 2018 9:29 am
Is there any small device that could optimally be relatively small, have some sort of networking capability (bluetooth), battery powered, able to be made waterproof (I guess that's just any case really), and also be able to measure how warm it is, whilst being able to withstand the temperature?

Basically I want to put a device like that in my pots and pans while I cook and have that device relay back to me (on my AR helmet) their temperatures.
You want a device, buried in sukiyaki or baked beans, to be able to communicate via bluetooth?

Octradox
Posts: 22
Joined: Fri Jun 23, 2017 5:53 pm

Re: Detect heat of stovetop?

Mon Feb 12, 2018 12:47 pm

PiGraham wrote:
Mon Feb 12, 2018 9:44 am
There are various ways to measure temperature without the sensing device getting hot.
A thermal camera
https://learn.adafruit.com/adafruit-amg ... mal-camera

An Infrared Thermometer
https://www.amazon.co.uk/Thermometer-Ta ... hermometer

A non-contact temperature sensor
https://www.sparkfun.com/products/9570

These all depend on the emissivity of the surface your are measuring. Shiny metal or clear liquid won't read as well as a mat black surface.


You can also get food thermometers designed to be inserted into food and made of food safe materials that can be properly cleaned. Some have wireless connection to a display. Some have Bluetooth and it might be possible to connect to them with Pi3 or Pi0W's onboard Bluetooth. It may be difficult to make that work.
Wow, awesome resources! I'll probably go a thermometer attached to maybe some low powered arduino to send via bluetooth. Unsure how I'll mount it but it'll be fine.

Alternatively I might attach to the pi headset to see whatever im looking ats temp, which is neat but per stovetop is better...

That thermal cam tho... unlimited budget id get that.

Octradox
Posts: 22
Joined: Fri Jun 23, 2017 5:53 pm

Re: Detect heat of stovetop?

Mon Feb 12, 2018 12:52 pm

scotty101 wrote:
Mon Feb 12, 2018 9:54 am
I've seen non-contact thermometers mounted above a hob before. If I remember correctly the person had used I sensor per 'hob plate' and had some form of LCD display showing the temperature of each object. Could probably be adapted to send data over a wireless protocol.
Ooo, I'd be interested in doing that. Do you have a link to project?

PiGraham
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Location: Waterlooville

Re: Detect heat of stovetop?

Mon Feb 12, 2018 1:53 pm

I sense you are going for very very cheap here.
You might try thermistors which are like temperature dependent resistors.

Look for glass bead thermistors used in 3D printers. They should cope with 250 °C or more typical hot end temperatures and come with heat resistant leads attached. Should be cheap as chips too.

According to this random internet post hob temp might be 400 ° (200°C) on high, but don't rely on that.

I'm assuming conventional electric hob here. Don't use on gas or induction hobs.

NB Electricity and heat are dangerous (and food hygiene matters)! Non-contact seems a better bet to me.

Octradox
Posts: 22
Joined: Fri Jun 23, 2017 5:53 pm

Re: Detect heat of stovetop?

Mon Feb 12, 2018 2:11 pm

PiGraham wrote:
Mon Feb 12, 2018 1:53 pm
I sense you are going for very very cheap here.

...

NB Electricity and heat are dangerous (and food hygiene matters)! Non-contact seems a better bet to me.
Not very very cheap, but I dont want to spend $100 on a single component (thermal camera). If the whole project costs roughly $50- $70 aud I'm happy.

And yeah i agree, non-contact does seem easier to me. No destruction, no washing. I didn't know there were so many non-contact options/ glad i posted.

PiGraham
Posts: 3667
Joined: Fri Jun 07, 2013 12:37 pm
Location: Waterlooville

Re: Detect heat of stovetop?

Mon Feb 12, 2018 2:17 pm

The other option is just to use a standard themometer that you put into the food as needed.

Cheap and some even talk to you.
https://www.ebay.co.uk/itm/Digital-Ther ... SwNchaLrlR

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