example.yaml

# Packages define a logical collection of SBP messages. Packages can
# in turn include other packages in the directory hierarchy. A package
# identifier specifies a directory path for the generated code,
# followed by an optional description used for documentation. By
# convention, packages marked as "stable" are unlikely to change much
# in the future, whereas unstable messages may change with future
# firmware development. Some packages are purely informative and are
# omitted from code generation using "render_source".

package: example
description: Geodetic navigation messages and friends.
render_source: True
stable: True
include:
  # types.yaml defines common primitives used in the spec.
  - types.yaml

# The definitions in a package can contain both SBP messages and
# struct definitions.

definitions:

 # A definition contains a series of named keys, many of which are
 # optional, such as "short_desc", "id", etc. By default, any
 # definition containing the 'id' field is considered an SBP message;
 # the 'id' field uniquely identifies the message type of the payload
 # contents. Defined fields layout the structure of an SBP payload.
 #
 # For example, an SBP message with a message type_id 0x0203 is a
 # MSG_BASELINE_NED instance, with a payload containing 'tow', 'n',
 # 'e', 'd', etc. data fields consumed by the user.

 - MSG_BASELINE_NED:
    id: 0x0203
    short_desc: Baseline in NED
    desc: |
        Baseline in local North East Down (NED) coordinates.

    # Each message definition has a series of fields, not unlike a C
    # struct. Each field has a type, which is either a primitive (e.g.,
    # u32 for 32-bit unsigned integer) or a more complex, predefined
    # type. You can optionally include units or a description.

    fields:
          - tow:
              type: u32
              units: ms
              desc: GPS Time of Week
          - n:
              type: s32
              units: mm
              desc: Baseline North coordinate
          - e:
              type: s32
              units: mm
              desc: Baseline East coordinate
          - d:
              type: s32
              units: mm
              desc: Baseline Down coordinate
          - n_sats:
              type: u8
              desc: Number of satellites used in solution

          # Fields that contain fields themselves denote bitfields.

          - flags:
              type: u8
              desc: Status flags
              fields:
                - 3-7:
                    desc: Reserved
                - 0-2:
                    desc: Fix mode
                    values:
                        - 0: Float RTK
                        - 1: Fixed RTK

 # Defitions lacking an id are not treated as SBP messages, but are
 # structured types that can be embedded into SBP definitions. Here,
 # UARTChannel is a struct composed of primitive types...

 - UARTChannel:
    desc: State of the UART channel.
    fields:
        - tx_throughput:
            type: float
            desc: UART transmit throughput.
        - crc_error_count:
            type: u16
            desc: UART CRC error count.
        - tx_buffer_level:
            type: u8
            desc: UART transmit usage percentage.

 # ... that can be used as a field in an actual SBP message...

 - MSG_UART_STATE:
    id: 0x0018
    desc: Piksi message about the state of UART0.
    fields:
        - uart0:
            type: UARTChannel
            desc: State of the UART0 channel.

        # You can also define fixed-size strings and
        # fixed/variable-size arrays!

        - info:
            type: string
            size: 20
            desc: Info string of length 20 (bytes).
        - remaining_uart_array:
            type: array
            fill: UARTChannel
            desc: Array of UART channels.