ExtEvents.hs

{-# OPTIONS_GHC -fno-warn-unused-imports #-}
-- |
-- Module:      SwiftNav.SBP.ExtEvents
-- Copyright:   Copyright (C) 2015 Swift Navigation, Inc.
-- License:     LGPL-3
-- Maintainer:  Mark Fine <dev@swiftnav.com>
-- Stability:   experimental
-- Portability: portable
--
-- Messages reporting accurately-timestamped external events, e.g. camera
-- shutter time.

module SwiftNav.SBP.ExtEvents where

import BasicPrelude as P
import Control.Lens
import Control.Monad.Loops
import Data.Aeson.TH           (defaultOptions, deriveJSON, fieldLabelModifier)
import Data.Binary
import Data.Binary.Get
import Data.Binary.IEEE754
import Data.Binary.Put
import Data.ByteString
import Data.ByteString.Lazy    hiding (ByteString)
import Data.Int
import Data.Word
import SwiftNav.SBP.Encoding
import SwiftNav.SBP.TH
import SwiftNav.SBP.Types

msgExtEvent :: Word16
msgExtEvent = 0x0101

-- | SBP class for message MSG_EXT_EVENT (0x0101).
--
-- Reports detection of an external event, the GPS time it occurred, which pin
-- it was and whether it was rising or falling.
data MsgExtEvent = MsgExtEvent
  { _msgExtEvent_wn  :: Word16
    -- ^ GPS week number
  , _msgExtEvent_tow :: Word32
    -- ^ GPS time of week rounded to the nearest millisecond
  , _msgExtEvent_ns  :: Int32
    -- ^ Nanosecond residual of millisecond-rounded TOW (ranges from -500000 to
    -- 500000)
  , _msgExtEvent_flags :: Word8
    -- ^ Flags
  , _msgExtEvent_pin :: Word8
    -- ^ Pin number.  0..9 = DEBUG0..9.
  } deriving ( Show, Read, Eq )

instance Binary MsgExtEvent where
  get = do
    _msgExtEvent_wn <- getWord16le
    _msgExtEvent_tow <- getWord32le
    _msgExtEvent_ns <- fromIntegral <$> getWord32le
    _msgExtEvent_flags <- getWord8
    _msgExtEvent_pin <- getWord8
    return MsgExtEvent {..}

  put MsgExtEvent {..} = do
    putWord16le _msgExtEvent_wn
    putWord32le _msgExtEvent_tow
    putWord32le $ fromIntegral _msgExtEvent_ns
    putWord8 _msgExtEvent_flags
    putWord8 _msgExtEvent_pin

$(deriveSBP 'msgExtEvent ''MsgExtEvent)

$(deriveJSON defaultOptions {fieldLabelModifier = fromMaybe "_msgExtEvent_" . P.stripPrefix "_msgExtEvent_"}
             ''MsgExtEvent)
$(makeLenses ''MsgExtEvent)