[HN Gopher] Temperature-Sensing Stirbar with RFID
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Temperature-Sensing Stirbar with RFID
Author : cl3misch
Score : 74 points
Date : 2024-01-13 10:52 UTC (12 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| cl3misch wrote:
| See also the more detailed Youtube video "Temperature-sensing
| RFID tag in magnetic stir bar"
|
| https://www.youtube.com/watch?v=nh1SIfipQs4
| londons_explore wrote:
| I'm surprised there isn't a single-chip solution to this...
|
| Almost every nontrivial chip has a temperature sensor inside
| (used for temperature compensation of factory calibrated stuff).
| I expect RFID chips are no different.
|
| Can't you just get an off the shelf NFC memory chip or something,
| then figure out what combination of register reads are necessary
| to read it's internal temperature sensor?
| bboygravity wrote:
| Ever looked up the accuracy of those built-in sensors?
|
| Rough estimate based on experience +/- 2 C at best.
|
| I'm not a chemist or microbiologist but I imagine they'd need
| better than that?
| londons_explore wrote:
| When calibrated they're usually far better than that. Just
| they normally aren't factory calibrated because temperature
| sensing isn't the primary purpose of the chip and calibrating
| temperature sensors is very expensive at scale (have fun
| heating up every wafer to a very precise 100C and cooling it
| down to -40C just to record temperature sensor output).
|
| Having said that, single point calibration is cheap to do
| (just calibrate at room temp) and pretty effective.
| m463 wrote:
| wouldn't it be easy at scale if you have RFID?
| 0xEF wrote:
| Heck, you need more accuracy than that for a proper cup of
| tea or coffee.
|
| That level of accuracy would also be useful in candy making,
| a secret hobby of mine. The cheap thermometers tend to have
| that margin of error and are pretty terrible at showing just
| how uneven the heat in a pan can be but I am not sure ic that
| has more to do with the sensors sensitivity or the refreshing
| on the cheap LCD display they tend to put on them.
| Cheer2171 wrote:
| > Heck, you need more accuracy than that for a proper cup
| of tea or coffee.
|
| No, 2 degrees C is about the right accuracy you need for a
| "proper" cup of tea or coffee. You'll lose that much heat
| in the transfer from kettle to cup. Inaccuracy of 5 degrees
| C in brewing will be indistinguishable for most people.
|
| Precision also has a placebo effect. Coffee or tea will
| taste better to you if you put a lot of work into it.
| regularfry wrote:
| > Coffee or tea will taste better to you if you put a lot
| of work into it.
|
| This is commonly known as the IKEA effect.
| ithinkso wrote:
| > Coffee or tea will taste better to you if you put a lot
| of work into it.
|
| This is very true but, tangentially, this is the opposite
| when you make drink/food for others. I found that you get
| the best effect when you spend a lot of effort to cook
| and perfect the dish but when asked, you have to pretend
| you basically winged it and it wasn't a hassle
| ta988 wrote:
| In chemistry it is usually fine, in microbiology it can have
| a serious impact on yoeld. But those sensors can often be
| calibrated just with a simple coefficient.
| HankB99 wrote:
| I wonder if the internal heating of the chip would affect the
| reading.
|
| My related experience was positioning a temperature sensor
| above a Raspberry Pi Zero and the couple watts produced by the
| Pi was enough to affect the measurement.
| Aurornis wrote:
| NFC chips don't have any need for temperature data, so a
| temperature sensor and the necessary blocks to convert it to
| digital wouldn't be a priority for a cost reduced NFC design.
|
| NFC gear is low bandwidth and low power. They don't need to
| monitor temperature like you would in a high performance CPU or
| memory chip.
| azubinski wrote:
| There are single chip NFC interfaced temperature meters of
| course.
|
| For example, https://ams.com/wireless-sensor-tags-interfaces
| endiangroup wrote:
| AD: Yes, what a wonderful application of tech. I very much enjoy
| seeing these hardware <> software open source projects.
| Congratulations on developing a finished project.
| HPsquared wrote:
| Such an elegant solution. This method could also be used to embed
| similar things.
|
| How about humidity sensors embedded inside buildings? Like, the
| builder could throw a couple of them into a wall when they build
| it, and trivial to scan and measure the temperature or internal
| humidity level inside the wall (or other equipment, maybe
| industrial equipment) during routine inspections.
| waldothedog wrote:
| This is being done in the "high performance" home building
| space. I don't think it's standard practice, but it gets talked
| about on the Fine Home Building podcast a decent amount
| stavros wrote:
| This seems like a great solution, I wonder why they didn't move
| on to selling this. Maybe because that's not as much fun as
| making it.
| themoonisachees wrote:
| Because the people using the old solution aren't the ones
| buying it. A chem lab is going to be stocked with the equipment
| everyone used in chem school, and the people who went to chem
| school are going to require that equipment. Yes, it'd trivial
| to change processes to use this new solution, but every chem
| lab in existence already has a thermometer and a hot plate with
| stirring, so the expense makes very little sens on its own.
| apprenticemason wrote:
| I created a similar product almost 10 years ago, I had a
| provisional patent filed and showed it off to some very nice and
| smart people at Thermo Fisher. I wanted to license the patent to
| people that actually know how to build laboratory equipment (I
| don't hold a higher degree in anything). I should've continued
| trying to license but they convinced me that was the wrong move.
| I formed a company and got $50k in grant money from the state of
| Wisconsin along with incubator space and advisors. I did all the
| initial software and hardware development, the first one I built
| took components from a battery powered toothbrush to inductively
| charge so I didn't need a charging port exposed to solutions. I
| loved working on this project, I had the idea after having
| frustrating experiences working with 30 year old lab equipment
| that took up more bench space in the lab than my backpack did. At
| the end of the day that's all it was. I had no idea wtf I was
| doing and the company eventually folded as real life became too
| much to juggle with my project. I figured I could use the same
| form factor to build tons of different sensors based on the many
| different ion selective electrodes already on the market.
| Eventually I needed to try and manufacture these sensors myself
| in a form factor that would fit inside flasks in the lab.
|
| Letting this project fall by the wayside is probably the single
| greatest regret of my life. I often think back about how
| different things could've turned out if only I had made the
| correct decisions and executed properly and actually found
| someone to license my patent... so it goes.
|
| https://m.youtube.com/watch?v=RrBhliK1ryY&pp=ygUbUGhpbmRpbmc...
| kohbo wrote:
| That's rough. Thanks for sharing your experience. On the other
| side, I hope your life came together in other ways.
| zafka wrote:
| Hi, my email is in my profile if you care to connect. I started
| an apprenticeship as an electrician at the age of 27. I
| received my Journeyman's card at 31 - Funny thing is that here
| in FL, there is next to no benefit in having a journeyman card
| unless you are using it as a stepping stone to a Master's
| license. There was a severe building slump when I got my card,
| so i figured it was a good time to go back to school full time.
| ( I had been going part time while working as an electrician.)
| Now quite a few years later .... Hell, not gonna bore everyone.
| Anyhow, give me a yell if you feel like it.
| bkraz wrote:
| I'm always happy to see one of my own projects on Hacker News.
| Let me know if you have any questions.
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