PAYLOAD_VERSION   <0> ->
    <- PAYLOAD_VERSION VersionInfo  was (all 0xFFFF means no app) NOW: NACK on no version

   PAYLOAD_ERASE <0>  ->
   <- ACK 2 (entered bootloader mode)

   PAYLOAD_DFU_PACKET  WriteDfu ->
   <- ACK 1

   ...

  PAYLOAD_VALIDATE <0> ->
  <-ACK 3 (applicaiton)

  PAYLOAD_MODE_CHANGE ->
  <- PAYLOAD_DATA_FRAME    -or-  ACK <nack> if application wrong

  DATA_FRAMES forever!
  ...


b
1