'****************************************************************************
'*
'* Copyright:    1992-1995 Pico Technology Limited
'*
'* Module:       ADC-10.BAS
'*
'* Author:       Alan Tong
'*               Pico Technology Limited
'*               Broadway House
'*               149-151 St Neots Road
'*               Hardwick
'*               Cambridge CB3 7QJ. U.K.
'*               Tel. 01954 211716
'*               Fax. 01954 211880
'*               Email: 100073,2365@compuserve.com
'*
'* Connections to ADC-10:
'*   Control: Output Address
'*
'*     Bit  7   6   5   4   3   2   1   0
'*     Pin  9   8   7   6   5   4   3   2
'*         PWR PWR PWR PWR PWR PWR *CS CLK
'*
'*   Input: Input Address
'*
'*     Bit  7   6   5   4   3   2   1   0
'*     Pin 11
'*         DATA
'*
'* Description:  This module contains a Quick Basic routine to drive
'*               the PICO ADC-10.  It was written using the 'QBASIC'
'*               program supplied with DOS 5.
'* History:
'*   ?????92 ADT Created
'*   09Sep93 MKG Add notes on use of DEBUG
'*   16Sep93 MKG Use constants for bits
'*   20Sep93 ADT Autodetection of printer port addresses
'*   27Sep93 ADT Changes following review
'*   29Sep93 MKG Add revision info
'*   11Feb95 MKG Ask for port
'*
'* Revision Info: "file %n date %f revision %v"
'*                "file ADC-10.BAS date 11-Feb-95,17:32:30 revision 4"
'*
'****************************************************************************

'define subroutines
DECLARE SUB Adc10DriverOpen (port)
DECLARE SUB ADC10GetValue ()


'define constants
CONST POWER% = &HFC
CONST POWEROFF% = &H0
CONST CS% = &H2
CONST CLOCK% = &H1
CONST clocklow% = &HFC
CONST DATABIT% = &H80

'global variables
DIM SHARED outputaddress%
DIM SHARED portin%
DIM SHARED adc%

'***************************************************************************
'*
'*   Start of program
'*
'***************************************************************************


    'say hello
    PRINT "ADC-10 BASIC driver: Version 1.3"
    PRINT "Copyright 1992-1995 Pico Technology Limited"

    'ask which port to use...
    ' port is 1 for LPT1, 2 for lpt2 etcetera
    INPUT "Printer port (1..4):", port
    CALL Adc10DriverOpen(port)

    PRINT "Press any key to start displaying readings"
    PRINT "Press a key again to stop"

    WHILE INKEY$ = ""
    WEND
debut = TIMER
    WHILE INKEY$ = ""

        CALL ADC10GetValue
        PRINT "ADC-10 reading = "; adc%,
        PRINT USING "ADC-10 voltage = #.## V"; ((5 * adc%) / 255)
        compteur = compteur + 1
    WEND
    
 PRINT compteur / (TIMER - debut); "mesures par seconde."
END

'***************************************************************************
'*
'* Adc10DriverOpen
'*   This routine sets port addresses and powers up the ADC-10
'*
'* accepts:
'*    1 - use LPT1
'*    2 - use LPT2
'*    3 - use LPT3
'*    4 - use LPT4
'*
'* sets:
'*    outputaddress
'*    portin
'*
'***************************************************************************
'
SUB Adc10DriverOpen (port)

'read the port addresses from the BIOS
  DEF SEG = 0
  addr% = &H408 + 2 * (port - 1)
  outputaddress% = PEEK(addr%) + (PEEK(addr% + 1) * 256)
  portin% = outputaddress% + 1

'power up the ADC-10
  OUT outputaddress%, POWER% + CS%

END SUB

'***************************************************************************
'*
'* Adc10GetValue
'*   This routine starts a new conversion and gets the result of
'*   the PREVIOUS conversion. (The first result is invalid as no
'*   conversion has been performed).
'*
'*   Sets:
'*     adc% - result of previous conversion
'*
'***************************************************************************
'
SUB ADC10GetValue

        OUT outputaddress%, POWER%              ' chip select low

        bits% = 0       'data is read into this string one bit at a time

          ' FOR j% = 1 TO 8 'read in 8 bits from ADC-10 (or TLC548) serially
          FOR j% = 1 TO 9 'read in 9 bits from ADC0831 serially


            OUT outputaddress%, POWER% + CLOCK% 'switch clock high

            'the next line reads the input port, then performs an 'AND'
            'to leave only the data bit from the ADC-10 that we want.
            'Next it does a binary shift to the left by multiplying by two

            bits% = (INP(portin%) AND DATABIT%) + bits% * 2

            OUT outputaddress%, POWER%          'switch clock low


          NEXT


        OUT outputaddress%, POWER% + CS%        ' chip select high

        ' divide the accumulator by DATABIT% and invert the bits
        adc% = (bits% / DATABIT%) XOR &HFF


END SUB