Bmp180 wrong values

Projects General Guidance
1

Hi everyone!

Today I have a new problem. I build a weather station which masure:

  • temperature and humidity DHT11/DHT22 (inside and outside)
  • time Ds3231 ( inside)
  • temp, alt, press BMP180 (outside)

My problem is from BMP180 sensor:

  • alt is totaly wrong (my zone 300m and bmp sensor 70 - 200m);
  • press is wrong

From here I buy the sensor:

Codes:

-inside

Inside_Code.ino (3.7 KB)

-outside

Outside_Code.ino (2 KB)

Can someone explain me what is the problem pls?

2

may be worth trying the SFE_BMP180 library

3

Code not posted the correct way. Use code tags, </> before pasting.
As my equipment can't read the files You get no helping reply.

4

The sensor only knows the air pressure where you are.

To calculate you your altitude, you have to tell the library the current pressure at sea level. Since you don't provide that value it assumes a constant: 101325. If that constant is not correct, your altitude will not be correct.

To calculate the pressure at sea level you have to tell the library your altitude. Since you don't provide that value it assumes you are at altitude zero (sea level). If that is not correct, your sea level pressure will not be correct.

5

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