#define SOH 0x01
#define STX 0x02
#define ETX 0x03
#define EOT 0x04
#define ACK 0x06
#define BS  0x08
#define LF  0x0a
#define CR  0x0d
#define XON 0x11
#define XOFF 0x13
#define NAK 0x15
#define CAN 0x18
#define CTLZ 0x1a
#define ESC 0x1b
#define DEL 0x7f