Reading Hex/Binary from PC serial then output

[DaveX]

@eperic

Still wonder how arduino would know when to start reading the full 30 bytes though.

Did you check out:

@DaveX

Serial Input Basics - updated by @Robin2 -- How to read serial input without blocking other code from running.

Reading a byte 0x12 ( Form Feed/ New Page) as the end of record, an then you reset to fill up a new message.

Or better -- treat 0x04 (EOT) as the end of message, and ignore the messages that don't start with 0x09.