BMP085 Temperature Wrong and not changing

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creese
 
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BMP085 Temperature Wrong and not changing

Post by creese »

Hello,

I have a BMP085 board hooked up to an arduino nano. I've got the test code running: https://github.com/adafruit/Adafruit-BM ... BMP085.cpp

Works great, but the temperature reads 40.94 and does not change. It's closer to 15C and it does not go up or down even if I blow hot air on it, put my thumb on the chip, or otherwise. I enabled debug in the BMP085 library, and the raw value is 32772-32774. So technically it does change, but this is just noise.

Any ideas on what I can check? I don't see much around about problems with this chip, so I'm beginning to assume this is a hardware issue. I ordered a couple BMP180s, but they aren't even shipping at the moment.

Help?

Thanks,
Colin

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adafruit_support_mike
 
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Re: BMP085 Temperature Wrong and not changing

Post by adafruit_support_mike »

The file you linked is the main library code, which doesn't do much on its own.

Do you get any results from the 'bmp085test' example sketch included with that library?

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creese
 
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Re: BMP085 Temperature Wrong and not changing

Post by creese »

That's what I meant to link, and yes, it executes fine and spits out results. I'd written a lot of code on top of it and a LSM303DLHC before I realized the results were bunk.

Colin

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creese
 
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Re: BMP085 Temperature Wrong and not changing

Post by creese »

bump?

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adafruit_support_mike
 
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Re: BMP085 Temperature Wrong and not changing

Post by adafruit_support_mike »

If I understand you correctly, the example script works and the BMP085 reports the right values when running that code. The problem occurs in your own code.

If that's right, please post your code and we'll take a look.

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creese
 
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Re: BMP085 Temperature Wrong and not changing

Post by creese »

No. Your code runs and the values are incorrect.

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creese
 
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Re: BMP085 Temperature Wrong and not changing

Post by creese »

Typical output below. I can assure you I am not at 2085 meters. I assume this is due to an invalid temperature correction to the incorrect temperature. It's not 41C here.

Temperature = 40.94 *C
Pressure = 78791 Pa
Altitude = 2071.76 meters
Real altitude = 2085.94 meters

Temperature = 40.94 *C
Pressure = 78793 Pa
Altitude = 2071.96 meters
Real altitude = 2085.53 meters

Temperature = 40.94 *C
Pressure = 78795 Pa
Altitude = 2072.06 meters
Real altitude = 2085.73 meters

Temperature = 40.96 *C
Pressure = 78792 Pa
Altitude = 2071.86 meters
Real altitude = 2085.94 meters

Temperature = 40.94 *C
Pressure = 78790 Pa
Altitude = 2072.06 meters
Real altitude = 2085.43 meters

Temperature = 40.94 *C
Pressure = 78789 Pa
Altitude = 2072.06 meters
Real altitude = 2085.53 meters

Temperature = 40.94 *C
Pressure = 78791 Pa
Altitude = 2071.25 meters
Real altitude = 2085.94 meters

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creese
 
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Re: BMP085 Temperature Wrong and not changing

Post by creese »

Hello? I'd like to send this thing back and exchange for a BMP180. It simply doesn't work.

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Re: BMP085 Temperature Wrong and not changing

Post by adafruit_support_mike »

We can do that.

Send a note to [email protected] with a link to this thread and the folks there will help you.

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