'{$STAMP BS2}
'{$PBASIC 2.5}
'Altimeter 12 Bit scottalt1_2.bs2
'Version 1.2

' [Declarations]
adcBits     VAR   Word
maxalt      VAR   Word
grndlevel   VAR   Word
maindeploy  VAR   Word
delaybits   VAR   Word
abits       VAR   Word
bbits       VAR   Word
cbits       VAR   Word
dbits       VAR   Word
ebits       VAR   Word
fbits       VAR   Word
averbits    VAR Word
grnd  DATA Word 4095
log DATA Word 4095
mainde DATA Word 4095

' [Initialization]

CS      PIN 0
CLK     PIN 1
DataOutput PIN 2
DEBUG CLS


PAUSE 3000
FREQOUT 5, 1000, 2000
PAUSE 1000
FREQOUT 5, 1000, 2000                                         ' Warm up delay
HIGH CS                                            ' Records initial
LOW CS                                             ' ground level
LOW CLK                                            ' altitude.
PULSOUT CLK, 210                                   '
SHIFTIN DataOutput,CLK,MSBPOST,[grndlevel\13]      '
WRITE grnd, Word grndlevel

DEBUG "Start Altitude    ", DEC4 grndlevel         '

DO
  FREQOUT 5, 500, 5000                              'Mach Delay stops
  HIGH CS                                           'readings for set amount
  LOW CS                                            'of time in PAUSE.
  LOW CLK                                           '
  PULSOUT CLK, 210                                  '
  SHIFTIN DataOutput,CLK,MSBPOST,[grndlevel\13]     '
  READ grnd, Word delaybits                     '
LOOP UNTIL grndlevel +30 < delaybits:  PAUSE 6000 ' +30 keeps altimter from
                                                    ' starting until about 300'.

DO
    HIGH CS
    LOW CS
    LOW CLK
    PULSOUT CLK, 210
    SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\13]
    abits = adcbits

    HIGH CS
    LOW CS
    LOW CLK
    PULSOUT CLK, 210
    SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\13]
    bbits = adcbits

    HIGH CS
    LOW CS
    LOW CLK
    PULSOUT CLK, 210
    SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\13]
    cbits = adcbits

    HIGH CS
    LOW CS
    LOW CLK
    PULSOUT CLK, 210
    SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\13]
    dbits = adcbits


    HIGH CS
    LOW CS
    LOW CLK
    PULSOUT CLK, 210
    SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\13]
    ebits = adcbits


    HIGH CS
    LOW CS
    LOW CLK
    PULSOUT CLK, 210
    SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\13]
    fbits = adcbits

    averbits = abits + bbits + cbits + dbits + ebits + fbits / 6

    READ log, Word maxalt
    'DEBUG CR, "max altitude", DEC4 maxalt
    IF averbits < maxalt THEN WRITE log, Word averbits
    FREQOUT 5, 500, 1000
    PAUSE 100

    IF maxalt + 4 < averbits THEN HIGH 3  'The (+4) adds delay to deployment.
LOOP UNTIL maxalt + 4 < averbits : GOTO main

main:
DO
    FREQOUT 5, 500, 4000
    HIGH CS
    LOW CS
    LOW CLK
    PULSOUT CLK, 210
    SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\13]
    READ 0, Word grndlevel
    maindeploy = grndlevel - 75
    DEBUG CR, "main deployment", DEC4 maindeploy
    WRITE mainde, Word maindeploy
LOOP UNTIL adcbits > maindeploy: HIGH 4
END