LIS2DH12 internal temperature sensor

[Julien GRIVEAU]

Posted on March 15, 2017 at 11:21

Hello,

In my application I use a SAFT lithium battery (LS 26500). I'd like to detect it's end of live by measuring voltage value. The voltage value depends on current and temperature.

So, I'd like read the temperature from the accelerater sensor on my board.

The problem is that I saw this thread : 

https://community.st.com/message/132806

 

If I understand, the temperature value is not absolute. So, my question is : 

   - How do I calibrate the temperature sensor ?

   - What is the conversion factor to get the right temp value?

Thanks,

Julien.

[Miroslav BATEK]

Posted on March 15, 2017 at 14:39

The temperature sensor can be used to measure temperature variations. 

It isn't suitable to return absolute temperatures measures. The value represents difference respect to a reference not specified value.

 

 

You have to do the calibration in your microcontroller, the sensor doesn't have any embedded feature for calibration.

Basically you have to measure the reference value. Put the sensor in temperature chamber with constant and known temperature and read the temp value from the sensor.

The sensitivity of the sensor is 1 LSB/°C.

[S.Ma]

Posted on March 15, 2017 at 15:15

Remember that the sensor is in the silicon. Depending where the battery is, the measured temperature might be very different, possibly with some latency in temperature 'spreading' over the chassis. A good way to look at it is through an IR camera (similar to the ones used in Airport to check fever) such as FLIR cameras.