Missing and insufficient data read from embedded BMP180 pressure sensor in motion

[mertico]

Hey Everyone!

We're building an avionic system which will fly onboard on our rocket. And we have embedded BMP180 Pressure Sensor on our avionic system and we want to get smooth data when it is moving. Our BMP180 data is fine when it is not moving, but "the data from the sensor is not fine when it is moving".

Our question is how can we better read the BMP180 data while it is moving? Thank you for reading...

 

[jderimig]

Hey Everyone!

We're building an avionic system which will fly onboard on our rocket. And we have embedded BMP180 Pressure Sensor on our avionic system and we want to get smooth data when it is moving. Our BMP180 data is fine when it is not moving, but "the data from the sensor is not fine when it is moving".

Our question is how can we better read the BMP180 data while it is moving? Thank you for reading...

Can you be more specific on what you mean that the data is "not fine"?

 

[UhClem]

Plus of course details on how the data is being read. I2C? SPI? device configuration?

 

[cerving]

Not sure what you mean by "not fine", but if you're talking about noise in the readings, yes, you're going to get that. Baro sensors need a lot of filtering to help increase the SNR. Look up Kalman Filters... and "mach dip" while you're at it. Your PC board layout looks fine, though.

BTW, the BMP180 has been OOP for over 5 years, and is unobtainable from authorized Bosch distributors. We used it our earlier products and replaced it with a TE/Meas-Spec MS5637. There was no direct software-compatible replacement for the BMP180, and the MS5637 hit the price/performance/ease of use sweet spot.

 

[Voyager1]

We do need more details. When you say "moving", do you mean in actual flight conditions, or motion during ground testing? What is the sample rate, and is there any filtering on the data? How is it mounted in the rocket? Do you have sufficient pressure equalisation ports?

 

[OverTheTop]

In addition to what others' have said make sure you keep sunlight off your baro sensor. These sensors are somewhat light sensitive and will give strange results, especially if they get varying light levels.

 

[bdureau]

Which sensor resolution are you using? For my altimeters I use the low res so that I get more measures and then filter them.
You will have to give a bit more details on what you are trying to achieve