dvlopt.linux.i2c.bme280 — dvlopt/linux.i2c.bme280 1.0.0-beta0

Interface for talking to BME280 sensors via I2C.

Any IO operation might throw in case of failure, and do not forget to always select the proper slave.

Relies on :

https://github.com/dvlopt/linux.i2c.clj

compensation-words clj

(compensation-words bus)

Retrieves compensation words from the slave.

Each sensor behaves a little differently, hence raw data must later be adjusted using those words.

configure clj

(configure bus)

(configure bus configuration)

Configures a previously selected slave device.

The configuration map may have the following options :

::iir-filter

The internal IIR filter can be configured for when the environmental pressure is subject to many short-term
changes such as slamming a door or the wind blowing on the sensor. This will also affect temperature measurements.

The value is one of these coefficients :

    coefficient | samples to reach >= 75% of step response
    ------------------------------------------------------
       0 (off)  |  1
       2        |  2
       4        |  5
       8        | 11
      16        | 22

::mode

Mode is one of :

    :sleep
        No operation, all registers accessible, lower power, selected after startup.

    :forced
        Perform one measurement, store results and return to sleep mode. To do another
        measurement, call this function with forced mode again.
        Recommended for low sampling rate, or "à la carte".

    :normal
        Perpetual cycling of measurements and inactive periods.
        Recommended for high sampling rate.

If the device is currently performing a measurement, execution of mode switching is delayed
until the end of the currently running measurement period.

::oversampling.humidity ::oversampling.pressure ::oversampling.temperature

Oversamplings are one of (where 0 = disable measurement) :

    #{:x0 :x1 :x2 :x4 :x8 :x16}

::standby

Inactive duration period between 2 measurements, relevant for the :normal mode, in milliseconds.
Must be one of :

    #{:0.5-ms :10-ms :20-ms :62.5-ms :125-ms :250-ms :500-ms :1000-ms}

Cf. defaults for used values for missing options

cycle-duration clj

(cycle-duration)

(cycle-duration configuration)

Given a configuration map, computes the duration of a single measurement cycle in milliseconds.

Returns a map containing :maximum, the maximum duration :typical, the typical duration.

Cf. configure

defaults clj

Defaults values for options and keys used throughout this namespace.

read-sensors clj

(read-sensors bus compensation-words)

Reads data from the sensors and adjusts it using the given compensation-words.

Returns a map containing :

::humidity in %rH ::pressure in Pa ::temperature in °C

Cf. compensation-words

soft-reset clj

(soft-reset bus)

Orders the slave to perform a soft reset.

status clj

(status bus)

Retrieves the current status of the slave and returns a map containing

::copying-nvm? True when NVM data is being copied to image registers. ::running-conversion? True when a conversion is currently running.