' =========================================================================
'
'   File...... GPS_Time.BS2
'   Purpose... Simple GPS Demo using the BS2
'   Author.... Jon Williams
'   E-mail.... jwilliams@parallax.com
'   Started...
'   Updated... 02 FEB 2004
'
'   {$STAMP BS2}
'   {$PBASIC 2.5}
'
' =========================================================================


' -----[ Program Description ]---------------------------------------------


' -----[ Revision History ]------------------------------------------------


' -----[ I/O Definitions ]-------------------------------------------------

GpsPin          PIN     0                       ' serial in from GPS


' -----[ Constants ]-------------------------------------------------------

#SELECT $STAMP
  #CASE BS2, BS2E, BS2PE
    T1200       CON     813
    T2400       CON     396
    T4800       CON     188
    T9600       CON     84
    T19K2       CON     32
    T38K4       CON     6
  #CASE BS2SX, BS2P
    T1200       CON     2063
    T2400       CON     1021
    T4800       CON     500
    T9600       CON     240
    T19K2       CON     110
    T38K4       CON     45
#ENDSELECT

Inverted        CON     $4000
Baud            CON     T4800 | Inverted

UtcOfs          CON     24 - 6                  ' UTC offset (CST)


' -----[ Variables ]-------------------------------------------------------

tmBuf           VAR     Byte(6)                 ' time buffer
hr              VAR     Byte                    ' time fields
mn              VAR     Byte
sc              VAR     Byte


' -----[ EEPROM Data ]-----------------------------------------------------


' -----[ Initialization ]--------------------------------------------------

Setup:


' -----[ Program Code ]----------------------------------------------------

Main:
  ' get time from GPS stream
  SERIN GpsPin, Baud, 3000, No_Signal, [WAIT("GPRMC,"), STR tmBuf\6]

  ' extract values from buffer
  hr = (tmBuf(0) - "0" * 10) + (tmBuf(1) - "0")
  mn = (tmBuf(2) - "0" * 10) + (tmBuf(3) - "0")
  sc = (tmBuf(4) - "0" * 10) + (tmBuf(5) - "0")

  ' correct for location
  hr = hr + UtcOfs // 24

  ' display raw and corrected data
  DEBUG HOME,
        STR tmBuf\6,
        CR,
        DEC2 hr, ":", DEC2 mn, ":", DEC2 sc

  NAP 6
  GOTO Main
  END


' -----[ Subroutines ]-----------------------------------------------------

No_Signal:
  DEBUG CLS, "No GPS Signal..."
  PAUSE 2000
  DEBUG CLS
  GOTO Main 