spec.txt

[SHT2x Driver - Design spec]
[About] 
A driver package for PXT Makecode Microbit to use the SHT2x sensors:
SHT20, SHT21, SHT21 Humidity/Sensors sensors.

[Design]
read_humidity() - Reads relative humidity from the sensor, return in int as %RH
read_tempreture() - Reads temperature from the sensor, return float as degree C\

[Implementation]
Interacting SHM2x involves the I2C interface via an certain 7 bit address, 
I2c address for SHT2x: 0x40 - according to data sheet
    (not entirely sure how that address thing works, apprently the reference 
    code uses 0x80 which requires 8 bits).

I2C command codes: 
    - Trigger Temprature sensor - 0xE3
    - Trigger Relative Humidity sensor - 0xE5
    - Trigger Temprature sensor (non master holding) - 0xF3
    - Trigger Relative Humidity sensor (non master holding) - 0xF6
    
Output Format
    - 3 bytes in length
        - data1 - data2 - checksum < discard checksum if possible
        - last 2 bits are status bit - clear before converting
    - Temperature in C = -46.85 + 177.72 * data / 2^16
    - Relative Humidity in %RH = -6 + 125 * data / 2^16