FBM320 Module

This module contains the Zerynth driver for FBM320 digital barometer. The FBM320 is a digital pressure sensor which consists of a MEMS piezoresistive pressure sensor and a signal conditioning ASIC. The ASIC include a 24bits sigma-delta ADC, OTP memory for calibration data, and serial interface circuits. The FBM320 features I2C and SPI digital interfaces, the present library enables I2C only.

FBM320 class

class FBM320(drvname, addr=0x6D, clk=400000)

Creates an intance of the FBM320 class.

Parameters:

• drvname – I2C Bus used ‘( I2C0, ... )’
• addr – Slave address, default 0x6D. If SDO pin is pulled low, I2C address is 6C. If SDO pin is pulled high, I2C address is 6D.
• clk – Clock speed, default 400kHz

Barometer values can be easily obtained from the sensor:

from formosa.fbm320 import fbm320

...

fbm = fbm320.FBM320(I2C0)

temp, press, altitude = fbm.get_values()

set_osr(osr)

Parameters:osr – is the oversampling rate to set. Values accepted: 1024, 2048, 4096 or 8192.

Set oversampling rate.

get_temp()

Return the temperature in degrees Celsius.

get_press()

Return the pressure in hPa.

get_altitude(pressure)

Parameters:pressure – pressure value in hPa.

Return the altitude in metres.

get_values()

Return the temperature (°C), pressure (hPa) and altitude (m) in a list [temperature, pressure, altitude].