Humidity PCM offset to be applied to sensor measurement after conversion
from raw value. This can be used to apply external calibration, beyond what
is automatically done on-sensor.
The raw, integer measurement data from the sensor.
In order to get actual temperature/humidity values this needs to be
transformed. Normally, the transformations are done using the equations
(1), (2) and (3) from the sensor’s datasheet. This is what the usual
measurement API does, but accessing raw measurements is provided
as a convenience if you want to do your own calibration.
SHT40Driver is the main structure with which a user of this driver
interracts. It is generic over two parameters implementing embedded_hal
traits for the specific platform you’re using: I2c which must implement
embedded_hal::blocking::i2c::{Read, Write, WriteRead} and Delay which must
implement embedded_hal::blocking::delay::DelayMs.
Temperature offset to be applied to sensor measurement after conversion from
raw value. This can be used to apply external calibration, beyond what
is automatically done on-sensor.
Define the duration for which the built-in heater should be turned on. After
that time, the heater automatically turns off, without the need for any
additional I2C commands.
I2C addresses for SHT40 are fixed, and depending on the product number
the sensor uses either 0x44 or 0x45. Product numbers SHT4x-Axxx get
address 0x44, and SHT4x-Bxxx get 0x45. For example, SHT40-AD1B has
address 0x44 and SHT40-BD1B has address 0x45.
The accuracy of SHT40 is typically +/- 0.2C and at worst +/- 0.4C in the
interval [0..60]C. The worst case outside this interval is +/- 1C (for the
ends of the interval [-40..120]C.
The SHT40 sensor uses a 16-bit ADC for converting the analog
measurements into data, which is then calibrated on-sensor and then
sent via I2C. In the raw measurement, temp_ticks and rel_hum_ticks are
direct outputs after the calibration process and take values in the
[0 .. 2^16 - 1] interval.