3 ms·

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

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 3y ago
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 3y ago
  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 3y ago
    wouldn't it be easy at scale if you have RFID?
- 0xEF 3y ago
  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 3y ago
    > 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 3y ago
      > 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 3y ago
      > 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 3y ago
  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 3y ago
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 3y ago
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 3y ago
There are single chip NFC interfaced temperature meters of course. For example, https://ams.com/wireless-sensor-tags-interfaces https://ams.com/wireless-sensor-tags-interfaces

bboygravity 3y ago

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 3y ago
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 3y ago
  wouldn't it be easy at scale if you have RFID?
0xEF 3y ago
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 3y ago
  > 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 3y ago
    > 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 3y ago
    > 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 3y ago
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 3y ago

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 3y ago

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 3y ago

There are single chip NFC interfaced temperature meters of course. For example, https://ams.com/wireless-sensor-tags-interfaces https://ams.com/wireless-sensor-tags-interfaces