Adding a leading 0 to incoming HEX data for conversion to binary

Sme1986:
Hi all!
Thanks a lot for your help.

@anon57585045: What I doing it reading CAN-Bus Data from a Car. I get 8 * 8Bytes of Data, saved in an Array "rx_frame.dada.u8"

So in total, I receive 64 Bits of information.

But as others have pointed out, you are not receiving CAN data as a string of binary characters. You are receiving it as a series of bytes, which have all 8 bits, not just the bits that happen to get printed by the Arduino binary print method.

The real answer to my question, which is what are you doing with the binary string, is "nothing except looking at it and being confused". Because, the binary string is just one of many ways of printing it.

You may find this function useful: BitRead