== Communication protocol between CAN and CC2540 chip  [[BR]]


List of commands from CC2540 to CAN transiver: 
 1. Subscribe to a message
 2. Subscribe to a message with a bitmask
 3. Unsubscribe from messages
 4. Unsubscribe from messages with a bitmask
 5. List of all subscriptions 
 6. Reset filter state
 7. Passthrough message  

{{{
enum {
  CMD_SUBSCRIBE = 1,
  CMD_SUBSCRIBE_BITMASK,
  CMD_UNSUBSCRIBE,
  CMD_UNSUBSCRIBE_BITMASK,
  CMD_LIST,
  CMD_RESET,
  CMD_MSG
} cmd_type;

}}}


List of responces from CAN transiver: 

{{{
enum {
  ACK_SUBSCRIBE = 1,
  ACK_SUBSCRIBE_BITMASK,
  ACK_UNSUBSCRIBE,
  ACK_UNSUBSCRIBE_BITMASK,
  ACK_LIST,
  ACK_RESET,
  ACK_MSG
} cmd_type;

}}}


Command message structure

||= Byte =||= Bitmask =||= Description =||= Values =||
||     0        ||                      || Command code || 1 - 7||
||     1        ||                      || Payload size || 0 - 254||
||  2 - 255 ||                      || Payload ||||


Examples
 
{{{
   01:08:76:00:55:01:44:02:01:00
   03:02:76:00
   05:00
   06:00
   07:76:06:05:01:02:03:04:05
}}}

 1. byte - subsribe command
 2. byte - payload size 8 byte = 2 CAN message IDs * 4 byte each 
 3. - 10. bytes 0076h & 0155h