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Vkj.1
Associate II
September 5, 2021
Question

i am using lps22hh pressure sensor but when i try to read the data and compare with standard atmospheric pressure i am getting 910hpa,but is it i need to calibrate the sensor?

  • September 5, 2021
  • 7 replies
  • 3087 views

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7 replies

S.Ma
Principal
September 5, 2021

From previous generations of pressure sensors, usually after soldering on PCB, residual mechanical stress can cause slight pressure shift which you can SW compensate if needed. If the difference is very big, there is a SW driver pb or a system issue, in this case, test the pressure sensor in basic operating mode like FIFO bypass and 10 Hz sampling.

Now the atmospheric pressure that you may get on the web from nearby METAR data will probably be an easy way to compare if you don't have any reference pressure sensor nor tool.

Vkj.1
Vkj.1Author
Associate II
September 6, 2021

that doesn't matter either i am using continuous polling method or FIFO method to get the pressure and temperature data. whatever the method you have used but data will remain same right?

S.Ma
Principal
September 6, 2021

Do you confirm your sensor readings are ok? If you monitor the sensor, change pressure, the value changes?

Vkj.1
Vkj.1Author
Associate II
September 6, 2021

yes pressure and temperature value changes

S.Ma
Principal
September 6, 2021

If there is no info in datasheet about calibration shift after reflow, it means calibration after pcb assembly is required.

niccolò
ST Employee
August 3, 2023

Hi @Vkj.1 ,

as other users wrote, if the soldering profile was not followed, a calibration should be needed, for that you can use a reference sensor and then use the RPDS (18h,19h) register to stake into account the calibration offset.

anyway, the offset is strangely larger than normal, so I would like to know how you are reading the data: are you using default libraries? also, how are you making the conversion? 

If this answers your question, please, mark this as "best answer", by clicking on the "accept as solution" to help the other users of the community

Niccolò

Associate II
August 4, 2023

It should be obvious but I'd like to mention it just in case: One cannot directly compare the value reported by an absolute pressure sensor with the pressure value reported by the weather stations, because the latter is adjusted to pressure at sea level.