1 wire CRC checking

Well well, pretty long time since the last post, well what can I say, I'm still busy with school. However, recently (like a long time ago), when I was browsing avr-libc package's libraries, I stumbled upon a library, called util/crc16.h, which you may guessed, gives CRC checking utilities.
Now, in 1 wire exploration post, there was a CRC byte, when reading the scratchpad of DS18B20 temperature sensor. If you'd watch the datasheet, you would see that the equivalent polynomial function of the CRC was

CRC = X⁸ + X⁵ + X⁴ + 1

I'm not really sure what that means, but while browsing the library, I noticed a function named _crc_ibutton_update, which seemed to have the same CRC polynomial and was called iButton 8 bit CRC.
There was even an example code, but even without it, the function seems pretty convenient. Meaning that if we would take the code before, and make some changes, it would be:

    one_wire_receive (scratchpad, 9);

    uint8_t CRC = 0;
    for (i=0; i<8; ++i) {
      CRC = _crc_ibutton_update (CRC, scratchpad[i]);
    }

    if (CRC == scratchpad[8]) {
      debug_out ("CRC match!");
    }
    else {
      debug_out ("CRC mismatch :(");
    }

The new code can be found in the source code repository of the blog, under 1_wire_0/1_wire2_CRC.c. That's all for today!