' Reads an ADS7818 12-bit adc.  Output is to EXCEL if the StampDAQ micro
'   has been installed.  For this program, the transmitting antenna is rotating
'   receiving antenna is connected to a PC via a BS2 microcontroller.
'
' {$STAMP BS2}
' {$PBASIC 2.5}

' November 1, 2006
'
' ADS7818 Pin 7 (clock) goes to BS2 Pin 2
' ADS7818 Pin 6 (data) goes to BS2 Pin 1
' ADS7818 Pin 5 (convert) goes to BS2 Pin 0
'
' Define Inputs and Outputs
OUTPUT 2        'clock pulse, normal low
OUTPUT 0        'convert when goes low, normal high
INPUT  1        'data in - read 13 bits due to wasted clock pulse
INPUT  3        'used to gate the output on Pin 0
'
' Define Variables and Constants
AdcBits   VAR      Word        '12-Bit ADC result
Junk      VAR      Word        'Wasted, used to complete clocking
I         VAR      Byte        'Used as a counter to average ADC reads
Average   VAR      Word        'The average of 10 ADC reads
PinRead   VAR      Bit         'Use to check Pin 3 for a high signal

'**************************************************************************
' Define StampDAQ Data Structure
sPin      CON          16            'Serial Pin - P16, Programming port
Baud      CON          84            'Baud mode for a rate of 9600, 8-N-1

PAUSE 1000    'Allow data communications to stabilize
SEROUT sPin,Baud,[CR]   'Send a lone CR to ensure StampDAQ buffer is ready

'**************************************************************************
' Setup Columns in EXCEL for the EEPROM output
Configure:

SEROUT sPin,Baud,[CR,"LABEL,TIME,Point,Voltage",CR]  'Label 2 columns: Data # and Voltage

SEROUT sPin,Baud,["CLEARDATA",CR]    'Clear all data columns (A-J) in Excel
'
' Begin Main

FOR I = 1 TO 150

SERIN 3, 16468, [WAIT ("!")]

'Circle:
'  PinRead = IN3
'  IF PinRead = 0 THEN Circle

  Junk = 5         'Waste a clock cycle for the transmitter to output the zeros

  HIGH 0           'Start conversion bit high, serial out when it goes low
  LOW 0

  SHIFTIN 1, 2, MSBPOST, [AdcBits\13,Junk\3]

  HIGH 0

'Send String with data for Excel ********************
  SEROUT sPin,Baud,["DATA,TIME,", DEC I,",", DEC AdcBits,CR]

PAUSE 500

NEXT

STOP
END