Barometric Pressure Sensor SCP1000

Moskog

Anyone tried the Barometric Pressure Sensor SCP1000 (http://www.sparkfun.com:80/commerce/product_info.php?products_id=8161) with the BS2?
I found some PIC code example but no Pbasic. Anyone know about that?

KjellO


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Franklin

I wrote code for the propeller and think I ported it to the stamp but no longer have that code. Do you have a specific question?

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- Stephen

Moskog

No, no spesific question, I was looking for a sensor for my weather sensor project for measuring barometric pressure and found this one. I found it small and not too expensive but not sure on how to connect it to the stamp and how to make it communicate with the stamp. But maybe there are other, easier ways, maybe better sensors I coud use? Do you have any ideas?

KjellO

Franklin

I'm looking at these for my station. www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPX4115&nodeId=01126990368716

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- Stephen

MSDTech

I'm using the MPXA6115A (a similar chip from the same family)·and an LTC1298 to read the output voltage on my weather station. I posted the writeup at:
http://forums.parallax.com/forums/default.aspx?f=21&m=265354
Reading the voltage with the LTC1298 was fairly straight forward and is well documented at
http://www.parallax.com/Portals/0/Downloads/docs/prod/appkit/ltc1298.pdf
The tricky bit is converting the voltage to an understandable value. I'm not very good with the binary math, so I included a floating point co-processor in the design. The final equation I used, based on a cross-calibration with a reference barameter was DataOut = (((DataIN/36.864)+13.0457)*0.2953)-0.06, of course, you will probably need to use different constants to account for elevation and the manufacturing tolerances of the sensor.

Moskog

Thank you for reply, Franklin and MSDTech

As I understood, both MPX4115A and MPX6115A output an analog voltage depending on the pressure. I was not able to see the real difference between the two of them. The LTC1298 is a 12-bit AD converter. When I look at the Output versus Absolute Pressure diagram of both the MPX'es, the range of pressure goes from 5 to 120 kPa. With a LTC1298 i can get a very high resolution and I probably need that high resolution as the atmospheric pressure range from 94 to 104 kPa, right?

KjellO

Franklin

If you want to stay one wire Dallas makes a DS2450 quad AD chip. As to the resolution you set the AD chip to map the voltage range you are interested to it's input range. Each situation will be a little different but that's the idea.

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- Stephen