SensorsのトピックRe: C / C++ example for decoding FXPQ3115BV Pressure/Altimeter data

C / C++ example for decoding FXPQ3115BV Pressure/Altimeter data

ChameeraSubasinghe — Tue, 03 Feb 2026 21:37:28 GMT

In one of our designs we use FXPQ3115BV Pressure sensor.

We were able to get the Chip correctly communicating with the host micro-controller. We verified this by reading the WHO AM I register of the chip as mentioned in the datasheet sensor responded with 0xC5

After that we followed the flow chart for getting data using polling mode (Figure 7 page 14).

In the datasheet it says the Raw data is Q8.4 fixed point format for pressure.

My question is how we can convert thie Q8.4 fixed point data to usable values in our algorithms.

Do you have any C code showing us how to convert this Q8.4 Raw values to actual pressure values. (floating point number)

Re: C / C++ example for decoding FXPQ3115BV Pressure/Altimeter data

diazmarin09 — Wed, 14 Sep 2022 19:36:56 GMT

Hello,

I hope all is great with you.

In this case, I would like to recommend the following community post. I do recommend to review such example project and use it as a reference for your design.

MPL3115A2 - Bare metal example project

I hope this information will be useful for you.

Regards,

David

Re: C / C++ example for decoding FXPQ3115BV Pressure/Altimeter data

ChameeraSubasinghe — Wed, 14 Sep 2022 20:09:45 GMT

Yes.. that is the implementation i was looking for thanks.

Just a quick question regarding this sensor. When i start looking into stocks of this sensor for our pre-production run i saw that digikey saying that this component is now obsolete.

Is that actually correct? when is the end of life for FXPQ3115BV sensor? do you have an alternative for the sensor if it is indeed obsolete.

Re: C / C++ example for decoding FXPQ3115BV Pressure/Altimeter data

diazmarin09 — Wed, 14 Sep 2022 20:48:17 GMT

Hello,

Thank you for using the NXP communities. I am pleased to know that the material provided was useful for you.

You are correct, the FXPQ3115BV device is obsolete. In this case, the direct replacement will be the FXPQ3115BVST1 device. Unfortunately, such device is under development.

I hope this information helps.

Regards,

David