barometric pressure sensor

Hi there!

I want to make a audible (beeping) variometer like you use it for (para)gliding. I want to have a very sensitive one, so noise, filtering and averaging will be a challenge.

At the moment I'm on the hardware part. The lower the noise and higher the accuracy, the easier the filtering. I have some standard BMP085 laying arround, but they seem too cheap for the quality I'm seeking.

What sensors can you recommend to me for my application?

Thanks!

How about the MS5611. One of the best MEMS pressure sensor available. When oversampling to an effective samplerate of 6,6Hz (150ms of sensordata) noise can be reduced to around 2 Pa or less.

With BMP085 you can achieve 0.3-0.5m altitude resolution with averaging/filtering.

I would recommend you the following Pressure sensor http://doproto.com/store/29-pressure-sensormpl115-module.html It provides very accurate digitized Temperature and Pressure sensor outputs with an inbuilt ADC.

Regards Polash

The BMP085 is very cheap and very accurate. The BMP085 in its highest resolution and the average of multiple samples will increase the accuracy even more then specified. I was indeed able to detect 30…50 cm change in height, which is almost unbelieveble for such a cheap sensor.

It’s successor is the BMP180. So the BMP180 will become the new standard.
There are good libraries for both.

Check the accuracy of the BMP180 against the sensors mentioned by the others to see which is the best.

some links

https://www.google.com/search?num=100&lr=&as_qdr=all&q=arduino+vario&oq=arduino+vario&gs_l=serp.3..0j0i22i30l9.17427.17427.0.19010.1.1.0.0.0.0.160.160.0j1.1.0....0...1c.1.32.serp..0.1.157.51iW0UpoTQk

The new LPS331AP appears to outperform the BMP180 in terms of noise and resolution: http://www.pololu.com/product/2126 It has a couple of nifty, user-settable alarm outputs too!