View Source BMP3XX
Read temperature and pressure in Elixir from Bosch environmental sensors such as BMP180, BMP280, BME280, BMP384, BMP388, BMP390, BME680, BME688, etc.
Usage
Here's an example use (most sensors are at address 0x77, but some are at 0x76):
iex> {:ok, bmp} = BMP3XX.start_link(bus_name: "i2c-1", bus_address: 0x77)
{:ok, #PID<0.2190.0>}
iex> BMP3XX.measure(bmp)
{:ok,
%BMP3XX.Measurement{
altitude_m: 100.11370638569619,
pressure_pa: 100387.23387754142,
temperature_c: 30.542875839950284,
timestamp_ms: 62437
}}
Depending on your hardware configuration, you may need to modify the call to
BMP3XX.start_link/1
.
See t:BMP3XX.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> BMP3XX.force_altitude(bmp, 100)
:ok
Subsequent altitude reports should be more accurate until the weather changes.