can anyone explain this function?

[Roberto]

Hi i have to read some data from a temperature sensor.

twi_temp_read((int8_t *)&temperature);

this below what do?

temperature = ((temperature >> 12) & 0x000F) | (temperature << 4);

if((temperature & 0x0800) != 0){
// minus
temperature--;
temperature ^= 0x0FFF;
sprintf(str, "-%03.4f", (float)temperature*0.0625);
}else{
    sprintf(str, " %03.4f", (float)temperature*0.0625);
}

Can anyone explain this function? thanks

[Jørgen Holmefjord]

Hi,

Where did you get this code from? Which sensor are you reading?

It looks like the code does conversion from binary to decimal temperature and stores this value in a string. For instance the TI TMP102 I2C temperature sensor has a resolution of 0.0625°C, and you would have to use a function like this to convert the binary value read over I2C if you want to display the value as decimal number.

Best regards,

Jørgen

[Roberto]

Hi Jorgen exact!is a tmp102! thanks