Modifications

The BMP280 is a Bosch sensor upgraded from the BMP085/BMP180/BMP183 serie. This sensor is really great to make environmental or weather measurements. Best of all, it can be used over an I2C or a SPI bus!

The BMP280 is a Bosch sensor upgraded from the BMP085/BMP180/BMP183 serie. This sensor is really great to make environmental or weather measurements. Best of all, it can be used over an I2C or a SPI bus!

[[fichier:BMP280.jpg|250px]]

[[fichier:BMP280.jpg|250px]]

=== technical details ===

=== technical details ===

* [http://df.mchobby.be/datasheet/bmp280.pdf Fiche technique du BMP280] (Bosch, pdf)

* [https://df.mchobby.be/datasheet/bmp280.pdf Fiche technique du BMP280] (Bosch, pdf)

* Size: 19.2mm x 17.9mm x 2.9mm

* Size: 19.2mm x 17.9mm x 2.9mm

* weight: 1.3 gr

* weight: 1.3 gr

This means that reference weather station applies the correction (compensating) to the read value.  

This means that reference weather station applies the correction (compensating) to the read value.  

For the reference station next to house, its height is 120m. so the correction adds the air column of 120m height over the sensor value to get the normalized SLP pressire. So the correction is evaluated to (120 / 8.3) hPa = 14.45 hPa.

For the reference station next to house, its height is 120m. so the correction adds the air column of 120m height over the sensor value to get the normalized SLP pressure. So the correction is evaluated to (120 / 8.3) hPa = 14.45 hPa.

{{underline|Let's apply the same principle to our BMP280 readings:}}

{{underline|Let's apply the same principle to our BMP280 readings:}}