Protocol Definition for TTX Beacon to Ground Stations
=====================================================


Introduction
------------

- using CW
- transceiver should send a beacon about every 60s
- transceiver sends acknowledge frame if requested
- parity 

Signs (Char Table)
------------------

!"$&'()+
,-./0123
456789:;
<=>?@ABC
DEFGHIJK
LMNOPQRS
TUVWXYZ


Base32 Coded Signs
------------------

   | 0 1 2 3 4 5 6 7 8 9 A B C D E F
-------------------------------------
00 | A B C D E F G H I J K L M N O P
10 | Q R S T U V W X Y Z 2 3 4 5 6 7

Values following this encoding scheme marked with: (Base32)


Character Coded Numbers
-----------------------

Num | Character
---------------
 0  | T
 1  | A
 2  | U
 3  | V
 4  | 4
 5  | E
 6  | 6
 7  | B
 8  | D
 9  | N

Values following this encoding scheme marked with: (NumChar)


Beacon Frame:
-------------

'N'       (1 Sign)   .. Start Character (-.)
CALLSIGN  (4 Signs)  .. the satellites call sign (i.e. OE0M)
CNT       (3 Signs)  .. beacon counter (Base32)
STATE     (1 Sign)   .. Base32 coded bitfield
CMDQLEN   (1 Sign)   .. Number of commands in queue (Base32)
... tba
CHECKSUM  (1 Sign)   .. Parity Sign


 Bitfields
 ~~~~~~~~~

  STATE:

  LSB     RX_STATE   .. Payload Receiver State (0 = OFF, 1 = ON)
  ... tba
  MSB    

Acknowledge Frame
----------------

'A'       (1 Sign)   .. Start Character (.-)
CRXCODE   (1 Sign)   .. unscrambled command code from CRX
CHECKSUM  (1 Sign)   .. Parity Sign