How Bmp180wokrs ??

Hello world, i need help please ..
I need to know how BMP180 measure Temperature, Pression, Pressure at sealevel ,Altitude, Real altitude??
and what the different between Altitude and Real altitude ??

It measures absolute pressure..

If you enter the current sea level pressure (found on a wheater site nearby yourself) into your code..
Of course: then it is possible to estimate/calculate youe elevation based on the pressure difference..

It measures pressure and temperature.

Check the manual of the library you use to find out what they mean with "altitude" and "real altitude".

If you know your elevation (altitude) you can calculate the "pressure at sealevel" (your local meteo service will give this number normally for air pressure) from your measured pressure.

Likewise, if you know the pressure at sealevel and measure the pressure at your location, you can calculate your elevation.

wvmarle:
It measures pressure and temperature.

Check the manual of the library you use to find out what they mean with "altitude" and "real altitude".

If you know your elevation (altitude) you can calculate the "pressure at sealevel" (your local meteo service will give this number normally for air pressure) from your measured pressure.

Likewise, if you know the pressure at sealevel and measure the pressure at your location, you can calculate your elevation.

So how it's mesure pressure at sea level, and I am far from the sea ?

atmospheric pressure changes constantly. atmospheric pressure changes with altitude. a pressure level by itself tells you nothing.

they had to choose something to be the standard. they chose X pressure at Y temperature at sea level to be the "standard day"

a pressure level at Z elevation above mean sea level can be converted mathematically to what it would be at sea level. from this, you can determine if the pressure where you are is above or below "standard"

the sensor tells you the pressure where you are. you do arithmetic to convert what it reads to sea level.