Difference between revisions of "Messages Format"

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(added s-pprz message def)
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==Paparazzi "PPRZ" standard message for direct serial connection==     
==Paparazzi "PPRZ" standard message for direct serial connection==     
===Pprzlink v1.0===


  PPRZ-message: ABCxxxxxxxDE
  PPRZ-message: ABCxxxxxxxDE
Line 19: Line 21:
     D PPRZ_CHECKSUM_A (sum[B->C])
     D PPRZ_CHECKSUM_A (sum[B->C])
     E PPRZ_CHECKSUM_B (sum[ck_a])
     E PPRZ_CHECKSUM_B (sum[ck_a])
===Pprzlink v2.0===
Note that there is currently no explicit way to recognize whether the protocol is v1.0 or 2.0 so it has to be known before the communication.
PPRZ-message: ABCxxxxxxxDE
    A PPRZ_STX (0x99)
    B LENGTH (A->E)
    C PPRZ_DATA
      0 SOURCE (~sender_ID)
      1 DESTINATION (can be a broadcast ID)
      2 CLASS/COMPONENT
        bits 0-3: 16 class ID available
        bits 4-7: 16 component ID available
      3 MSG_PAYLOAD
      . DATA (messages.xml)
    D PPRZ_CHECKSUM_A (sum[B->C])
    E PPRZ_CHECKSUM_B (sum[ck_a])
==Secure Paparazzi (S-PPRZ) for serial and transparent modem communication==   
The overhead is 16 bytes (4 bytes of counter, 12 bytes of tag), plus the necessary key exchange at the beginning of communication.
===S-Ppprzlink v1.0===
PPRZ-message: ABCxxxxxxxDE
    A PPRZ_STX (0x99)
    B LENGTH (A->E)
    C PPRZ_DATA
      0-3 COUNTER
      // ciphertext start
      4 SENDER_ID
      5 MSG_ID
      6 MSG_PAYLOAD
      . DATA (messages.xml)
      // ciphertext end
      7-18 TAG (12 bytes)
    D PPRZ_CHECKSUM_A (sum[B->C])
    E PPRZ_CHECKSUM_B (sum[ck_a])
===S-Pprzlink v2.0===
In this case we decrypt only packets with matching DESTINATION (or broadcast), to avoid decrypting unwanted data.
PPRZ-message: ABCxxxxxxxDE
    A PPRZ_STX (0x99)
    B LENGTH (A->E)
    C PPRZ_DATA
      0 SOURCE (~sender_ID)
      1 DESTINATION (can be a broadcast ID)
      2-5 COUNTER (4 bytes)
      // ciphertext start
      6 CLASS/COMPONENT
        bits 0-3: 16 class ID available
        bits 4-7: 16 component ID available
      7 MSG_PAYLOAD
      . DATA (messages.xml)
      // ciphertext end
      8-19 TAG (12 bytes)
    D PPRZ_CHECKSUM_A (sum[B->C])
    E PPRZ_CHECKSUM_B (sum[ck_a])


==XBee API format==
==XBee API format==
Line 57: Line 120:
       . DATA (messages.xml)
       . DATA (messages.xml)
     I CHECKSUM (sum[B->H])
     I CHECKSUM (sum[B->H])
==Secure Paparazzi (S-PPRZ) for serial and transparent modem communication==   
PPRZ-message: ABCxxxxxxxFG
    A PPRZ_STX (0x99) (1 byte)
    B LENGTH (A->E) (1 byte)
      C COUNTER (4 bytes)
        // ciphertext-start
        //  PPRZ_DATA
        D 0 SENDER_ID ( 1byte)
        D 1 MSG_ID (1 byte)
        D 2 MSG_PAYLOAD
        D . DATA (messages.xml)
        // ciptertext-end
      E tag (12 bytes)
    F PPRZ_CHECKSUM_A (sum[B->D]) (1 byte)
    G PPRZ_CHECKSUM_B (sum[ck_a]) (1 byte)


[[Category:Software]] [[Category:Developer_Documentation]]
[[Category:Software]] [[Category:Developer_Documentation]]

Revision as of 18:54, 31 August 2017

Introduction

Messages Format and how to use them

For the message definitions see http://docs.paparazziuav.org/latest/paparazzi_messages.html

Types

Paparazzi "PPRZ" standard message for direct serial connection

Pprzlink v1.0

PPRZ-message: ABCxxxxxxxDE
    A PPRZ_STX (0x99)
    B LENGTH (A->E)
    C PPRZ_DATA
      0 SENDER_ID
      1 MSG_ID
      2 MSG_PAYLOAD
      . DATA (messages.xml)
    D PPRZ_CHECKSUM_A (sum[B->C])
    E PPRZ_CHECKSUM_B (sum[ck_a])

Pprzlink v2.0

Note that there is currently no explicit way to recognize whether the protocol is v1.0 or 2.0 so it has to be known before the communication.

PPRZ-message: ABCxxxxxxxDE
    A PPRZ_STX (0x99)
    B LENGTH (A->E)
    C PPRZ_DATA
      0 SOURCE (~sender_ID)
      1 DESTINATION (can be a broadcast ID)
      2 CLASS/COMPONENT
        bits 0-3: 16 class ID available
        bits 4-7: 16 component ID available
      3 MSG_PAYLOAD
      . DATA (messages.xml)
    D PPRZ_CHECKSUM_A (sum[B->C])
    E PPRZ_CHECKSUM_B (sum[ck_a])


Secure Paparazzi (S-PPRZ) for serial and transparent modem communication

The overhead is 16 bytes (4 bytes of counter, 12 bytes of tag), plus the necessary key exchange at the beginning of communication.

S-Ppprzlink v1.0

PPRZ-message: ABCxxxxxxxDE
    A PPRZ_STX (0x99)
    B LENGTH (A->E)
    C PPRZ_DATA
      0-3 COUNTER
      // ciphertext start
      4 SENDER_ID
      5 MSG_ID
      6 MSG_PAYLOAD
      . DATA (messages.xml)
      // ciphertext end
      7-18 TAG (12 bytes)
    D PPRZ_CHECKSUM_A (sum[B->C])
    E PPRZ_CHECKSUM_B (sum[ck_a])

S-Pprzlink v2.0

In this case we decrypt only packets with matching DESTINATION (or broadcast), to avoid decrypting unwanted data.

PPRZ-message: ABCxxxxxxxDE
    A PPRZ_STX (0x99)
    B LENGTH (A->E)
    C PPRZ_DATA
      0 SOURCE (~sender_ID)
      1 DESTINATION (can be a broadcast ID)
      2-5 COUNTER (4 bytes)
      // ciphertext start
      6 CLASS/COMPONENT
        bits 0-3: 16 class ID available
        bits 4-7: 16 component ID available
      7 MSG_PAYLOAD
      . DATA (messages.xml)
      // ciphertext end
      8-19 TAG (12 bytes)
    D PPRZ_CHECKSUM_A (sum[B->C])
    E PPRZ_CHECKSUM_B (sum[ck_a])




XBee API format

XBee-message: ABCDxxxxxxxE
    A XBEE_START (0x7E)
    B LENGTH_MSB (D->D)
    C LENGTH_LSB
    D XBEE_PAYLOAD
      0 XBEE_TX16 (0x01) / XBEE_RX16 (0x81)
      1 FRAME_ID (0)     / SRC_ID_MSB
      2 DEST_ID_MSB      / SRC_ID_LSB
      3 DEST_ID_LSB      / XBEE_RSSI
      4 TX16_OPTIONS (0) / RX16_OPTIONS
      5 PPRZ_DATA
        0 SENDER_ID
        1 MSG_ID
        2 MSG_PAYLOAD
        . DATA (messages.xml)
    E XBEE_CHECKSUM (sum[D->D])

   ID is AC_ID for aircraft, 0x100 for ground station

Telemetry storage format for data logger

TLM-message: ABCDEFGHxxxxxxxI
    A PPRZ_STX (0x99)
    B LENGTH (H->H)
    C SOURCE (0=uart0, 1=uart1, 2=i2c0, ...)
    D TIMESTAMP_LSB (100 microsecond raster)
    E TIMESTAMP
    F TIMESTAMP
    G TIMESTAMP_MSB
    H PPRZ_DATA
      0 SENDER_ID
      1 MSG_ID
      2 MSG_PAYLOAD
      . DATA (messages.xml)
    I CHECKSUM (sum[B->H])