serial protocol

This  just barely scratches the surface of the serial protocol.

Ux.....xx   32-bit Unsigned integer (1 to 8 hex nybbles)

Ix.....xx   32-bit   signed Integer (1 to 8 hex nybbles - bit 3 of first nybble is the sign bit)

Fx.....xx   32-bit Float            (1 to 8 hex nybbles ... almost always 8)

Bxx..xxxx   Byte array or string    (even number of hex nybbles) ; exclude terminating 0

T           True

N           Nil/False (in Lua, false and nil are false - everything else is true)

Cxxx        Checksum modulo 0x1000  (1 to 3 hex nybbles)

TBD