HDC1000 Battery Configuration

Hallo,

I am using “HDC1008” sensor with “Arduino UNO”, its a Temperature and Humidity sensor. the data sheet can be found :

I have both prog for “Arduino UNO”, the prog are “Adafruit_HDC1000.h” and “Adafruit_HDC1000.cpp”

In the header file prog “Adafruit_HDC1000.h” written for battery status :

#define HDC1000_CONFIG_BATT   (1 << 11)

and in the data sheet → page 15 → Table 5 says :

in Register 0x02 the bit 11 have to be:

case1: Set(i.e. write 1)–> if we want to make the Battery status–> “Battery voltage < 2.8V (read only)”

case2: unset(i.e. write 0) → if we want to make the Battery status–> “Battery voltage > 2.8V (read only)”

now, my question is how Arduino programmer write 1 << 11 for case1 ? ? ?

I am not saying its wrong… I just want to understand it…

I will appreciate any help. better if any one can explain it clearly with calculation…

Thanks