MPL3115A2 noisy readings

[mattmabile]

I am using a MPL3115A2 sensor with an Arduino Mega 2560 microprocessor board.  I'm reading feet from the sensor, but the reading is fluctuating a lot and the initial reading seems to be incorrect.  I need the sensor to put out a steady non-fluctuating reading and I need it to be accurate within 0.1 inch.  Can anyone offer me some suggestions on how to accomplish my goal?

[TomasVaverka]

Hi Matt,

The sensor die is light sensitive and direct light exposure through the port hole can lead to varied accuracy of pressure measurement. Our recommendation is to avoid such exposure to the port during normal operation. For instance you can put a small piece of foam over the port to block out light, but still allow the air to reach the sensor. Using this and maximum oversampling (OS [2:0] bits = 0b111), you should be able to achieve much better results.

Also note that you can adjust the altitude using the built-in OFF_H (0x2D) register that offers user-set altitude offset adjustments in twos complement format with a scale factor of 1 m/LSB.

I hope it helps.

Regards,

Tomas

PS: If my answer helps to solve your question, please mark it as "Correct". Thank you.

[mattmabile]

Thanks Tomas, I will try this out.

Yeah, putting the sensor in a small enclosed box was going to be the next thing that I tried. I had no idea that light affected the sensor.

Sent from my iPhone