Read temperature and pressure from Bosch BMP280 and BME280 sensors in Elixir.
Add {:bmp280, "~> 0.2.0"}
to your project's dependencies. Here's an example
use:
iex> {:ok, bmp} = BMP280.start_link(bus_name: "i2c-1", bus_address: 0x77)
{:ok, \#PID<0.29929.0>}
iex> BMP280.read(bmp)
{:ok,
%BMP280.Measurement{
altitude_m: 46.60861034844783,
humidity_rh: 50.190531261362295,
pressure_pa: 100766.41878837062,
temperature_c: 17.373406414553756
}}
Depending on your hardware configuration, you may need to modify the call to
BMP280.start_link/1
. See t:BMP280.options/0
for parameters.
All measurements are reported in SI units.
The altitude measurement is computed from the measured barometric pressure. To be accurate, it requires either the current sea level pressure or the current altitude. Here's an example:
iex> BMP280.force_altitude(bmp, 100)
:ok
Subsequent altitude reports should be more accurate until the weather changes.
Successors to the BMP280 and BME280 look similar, but not tested yet. If you're using one of them, please help me by either verifying that they work or adding support for them.