Convert the UID of a 13.56 MHz card

To get the expected number out of the UID, you can convert the UID using the options described below. There are 4 options - so if you're in doubt, we recommend you try them all and test which ones work. Alternatively, you can order a configuration from us.

Rotate Bytewise

Try this if the expected number doesn't look at all like the UID. "Rotate Bytewise" applies to the binary format of the UID, i.e. the blocks of zeros and ones that the UID ultimately consists of (learn more about encoding). With this option, you get a mirror reflection of these blocks (referred to as bytes): The order is reversed, i.e the last byte is read first.

Example: Rotate UID of a 13 MHz card bytewise

Convert to decimal

Enable this checkbox if you want to convert the final output to decimal, i.e. the format of the expected number printed on the card. Otherwise, the number will be encoded in hexadecimal format (learn more about encoding).

Example: Convert UID of a 13 MHz card to a decimal number

Custom length

If your final number must have a fixed length, specify the number of digits here.
If the number you have so far is longer, excess digits are truncated at the front.
If the number you have so far is shorter, it will be prefixed with zeros.

Example: Cut UID of a 13 MHz card to a custom length

Remove leading "0"-digits

If your number starts with one or more zeros, you can remove them with this option.

Example: Remove leading zeros of a UID of a 13 MHz card

Here's how you can test if your project settings work.