spoof digital thermometer

[avivos120]

Hi.

I want make or buy digital thermometer that show
38.7C


How can i do it?
Thanx

 

[Harvey]

Unless you're an engineer or tech who wants to build one as a hobby project, building one would be expensive and time consuming.

Searching Google for digital thermometer finds pics that suggest that the unit in your pic is a Mabis digital thermometer.

Searching for Mabis digital thermometer finds many models and sources for them, some for under $4.

 

[Jaepheth]

Wait... do you mean you want a thermometer shaped LCD readout that will always read 38.7c ?

All you need to do is wire the correct voltages to the LCD leads. If memory serves they're typically powered by one set of pins and then each "bar" on the lcd has a data pin where '1' turns the bar off and '0' keeps the bar on.

You can grab a digital thermometer, crack it open and tinker with it. You'll need a soldering iron with a very fine tip and a stead hand.

I assume they work with a thermistor in the tip, so you could also just use an ohm meter to find what the resistance is when the thermometer reads 38.7, or when the thermistor is sitting in some 38.7c environment. and then bypass the thermistor with a fixed resistor.

Or just do what kids have been doing since the dawn of the excused absences and use a regular thermometer to quickly stir your coffee when your mom isn't looking.

 

[Harvey]

Wait... do you mean you want a thermometer shaped LCD readout that will always read 38.7c ?

Oops! Missed the word, "spoof" in the title. 😳

 

[imagoon]

Hi.

I want make or buy digital thermometer that show
38.7C


How can i do it?
Thanx

Sounds like someone wants to look "sick" on demand.

 

[DSF]

Assuming this is a get-out-of-school-sick play, what happens when your parent checks the reading again? Or uses the thermometer him or herself?

Or even just turns it on one day and finds it reading 38.7 from the get-go?

 

[mindless1]

There is probably a thermistor in the end of the thermometer. You'd disconnect that, measure its resistive value when raised to body temperature, then get a potentiometer with a max resistance value just a little above that thermistor value.

Put the pot in place of the thermistor and dial in the right resistance to reach 38.7C on the display then replace the pot with a resistor array of the same resistance value.

The problem is it will read 38.7C all the time, not just after being used to check someone's temperature.