Eric's Maxim/Dallas 1-Wire Online CRC Calculator




Maxim/Dallas 1-Wire devices use what is called Dow CRC to check that the data bytes were received correctly.
This returns an 8-bit CRC value as the last byte and uses a polynomial of X^8 + X^5 + X^4 + X^0.



Note!! Maxim themselves have used the wrong byte locations in some of their examples.

According to the downloadable Excel calculator found at this page, bytes 12AA125F14A21212 (byte 0 .. byte 7) would be followed by a CRC of 6D at byte 8.
In fact, to make this work, and to make it look like the order that the bytes are, in fact, sent by the the chip in, they need to be in reversed order: 1212A2145F12AA126D (byte 0 .. byte 8).




To find the CRC value of a string, please enter the string in HEX notation and click Find CRC.
(These should be entered starting with byte 0 on the left, and byte indexes increasing towards the right)

If you include the CRC value as the last byte, the calculated value will be 0x00.



(Values should be entered in the form A1FF0022... spaces are acceptable)

 


Bad Input Value! Values must be in hex!









Dow CRC calculator (C)opyright 2010 Eric Low.