Using the STM32 internal Temperature sensor

Posted on May 17, 2011 at 12:28

Can anybody help with using the STM32 internal Temp sensor.

The data sheet shows the formula required to generate output in degrees C, however the units of the read value (Vsense) are not stated.

Is there an example application showing correct use of this feature?

Cheers

Quote:

Temperature (in °C) = {(V25 - VSENSE) / Avg_Slope} + 25.

Where,

V25 = VSENSE value for 25° C and

Avg_Slope = Average Slope for curve between Temperature vs. VSENSE (given in

mV/° C or μV/ °C).

Refer to the Electrical characteristics section for the actual values of V25 and

Avg_Slope

Posted on May 17, 2011 at 12:28

Quote:

On 10-07-2008 at 14:50, Anonymous wrote:

Quote:

BTW, from the datasheet there are listed quite big variations of the temperature sensor parameters, so it could be used mainly for informative purposes.

The datasheet quotes +/- 1.5 degree accuracy. Are you saying that this can not be achived (and that the data sheet is incorrect?)

I need to achive a minimum of +/- 2 degree accuracy on my readings any suggestions how I do that?

The datasheet doesn't quote 1.5 degree absolute accuary. It quotes linearity with temperature accuracy. So if room temperature is 21 degrees it may indicated 50 degrees, but if you increase the room temperature to 31 degrees, the reading should be 60 degrees +/- 1.5 degrees.

you can calibrate the sensor by taking a reading at room temp and storing that into FLASH and using that as an offset to the equation, but there is no indication how long this will be accurate and how often you need to do this.

Posted on May 17, 2011 at 12:28

Quote:

BTW, from the datasheet there are listed quite big variations of the temperature sensor parameters, so it could be used mainly for informative purposes.

The datasheet quotes +/- 1.5 degree accuracy. Are you saying that this can not be achived (and that the data sheet is incorrect?)

I need to achive a minimum of +/- 2 degree accuracy on my readings any suggestions how I do that?

Posted on May 17, 2011 at 12:28

VSENSE is the measured voltage from the temperature sensor in the same units like V25 and Avg_Slope.

BTW, from the datasheet there are listed quite big variations of the temperature sensor parameters, so it could be used mainly for informative purposes.