LPS22HBTR sensor data error.

[DuncanR]

Dear ST/Forum,

Your attention would be much appreciated for a technical enquiry.

We are using the LPS22HB pressure and temperature sensors in some electronics for an experiment that will be onboard the International Space Station (ISS) in orbit later this year. We are having great success reading the sensors generally but we have an anomaly in the data if you could please advise. Our code is communicating with your chip in one-shot mode using the chip enable line and SPI serial bus. We are powering the devices from 3.3V and the code enables the chip, waits 100mS and then begins reading.

We are finding that the first pressure value and subsequent values all seem OK. However the first temperature reading is consistently 1 degree lower than all subsequent readings. This is consistent on one device and the same on all devices. Are you aware that the first temperature reading is known to be in error, or are we doing something wrong?

Please see the plot file from two devices attached. You can clearly see the jump in temperature. What I am concerned about is that the first reading may be correct and all the others offset by 1C, rather than assuming the first reading is incorrect.

Thanks and regards

Duncan

[Federica Bossi]

Hi @DuncanR ,

That sounds strange. Are you using our official drivers?

If not, can you try to implement them and let me know if you still have the problem?

[DuncanR]

Hi Federica,

Data is being successfully read from the device every time we use it and on every read without apparent error except for this first temperature reading. The comms seem simple and we have written our own Python code for Raspberry Pi, using the timing and register protocols listed in the device data sheet.

I will however pass the link to the C+ code to the software engineer, just in case it helps.

Thanks

Duncan