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Table of Contents
BME280 multi-purpose sensor
This multi-purpose sensor is used to measure temperature, relative humidity and barometric pressure. It operates as an I2C slave device.
The actual sensor is tiny but a board is available from China with the I2C connections and power on a standard 0.1 inch header which makes it easily accessible.
Raspberry Pi
The device uses I2C to communicate with a host master and with the Pi, four pins on the GPIO header are utilised to achieve this.
+---P1---+
3V3 01 .
SDA 03 .
SCL 05 .
. .
GND 09 .
. .
Relevant I2C pins shown, others omitted.
With the miniature board (purple device in photo), the four wires hook up the BME280 to the Pi. Two wires are for power and two for communications. Power is supplied from the Pi 3V3 pin which is connected to the board's Vin pin.
