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Associate
December 21, 2023
Question

Temperature Conversion - from the LIS3DH sensor raw value

  • December 21, 2023
  • 1 reply
  • 1885 views

Hello All,

Need to read the values from the embedded Temperature Sensor in LIS3DH via I2C communication 

I had made the following configurations as mentioned in the datasheet,

1. CTRL_REG4(0x23) = 0X80

2. TEMP_CFG_REF (1Fh) = 0XC0

3. Trying read the temperature value from the following register OUT_ADC_3_L(0x0C) and OUT_ADC_3_H(0x0D).

     - Getting the value from the OUT_ADC_3_H(0x0D) as 8. If I expose heat near to the chip the value is increasing. 

How to convert this(8) value to temperature?

Kindly assist me to get the conversation formula. Here the Vdd supply = 3.3V.

 

Thanks in Advance.

 

Regards,

Surya S 

  

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1 reply

Federica Bossi
Technical Moderator
December 21, 2023

Hi @Surya S ,

As reported in Table 5 of the datasheet, the temperature sensor output change vs temperature: 1 digit/degree of Celsius.

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Surya SAuthor
Associate
December 26, 2023

@Federica Bossi ,

 

Thank you for the update.

 

Here the thing is the unit we kept the unit under room temperature 25°C and the value read from the register OUT_ADC_3_H(0x0D) is 7. How can equate this  8 to 25°C? Attached image is for your reference.

 

SuryaS_0-1703582396726.png

Thanks In Advance.

 

Tesla DeLorean
Guru
December 26, 2023

You should be able to read both the low and high byte in a singular 2 byte read operation. What's that number pair?

Post code section using the ... </> tool in the post edit window, not as a bitmap

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