Color Scanner Serial Out

By Spencer Kiser

This code reads color values from the Taos TCS230 color sensor and sends them out serially in ASCII-formatted values.

This code for the Basic Stamp contains a calibration routine, scans and stores known color samples, and scans and identifies unknown samples. Spencer altered Jon's code to get it to send RGB values it finds out serial to MAX/MSP.

I added comments to indicate the changes I made to Jon Williams code. Basically I changed the ScaleMax variable from 100 to 255 because I wanted higher resolution of values, and Max takes RGB values on 0 to 255 scale. This creates another problem if you want to have a delimiter to separate the values. I have the RGB values coming out as an undelimited list of dec values, which is definitely not a robust way to do it. Also, I don't use his Calibrate_Colors or Match_Colors subroutines, because I don't need them. - Spencer

' =========================================================================
'
'   File....... Color_Scan.BS2
'   Purpose.... Color Scanner with TAOS TCS230
'   Author..... Jon Williams
'   E-mail..... jwilliams@parallax.com
'   Started.... 
'   Updated.... 18 APR 2003
'   Repurposed by...  Spencer Kiser
'

'
' =========================================================================


' -----[ Program Description ]---------------------------------------------
'
' Simple color scanner using the TAOS TCS230 color sensor. This program
' uses a direct connection; the TCS dual-sensor adaptor (which is docu-
' mented with the sensor) is not used.
'
' NOTE: OE\ must be tied low to enable TCS230 output and allow control 
'       over LEDs.
'
' NOTE: To prevent sensor damage, download the program and run it before
'       connecting the TCS230.


' -----[ Revision History ]------------------------------------------------


' -----[ I/O Definitions ]-------------------------------------------------

TcsLeds         PIN     0                       ' LEDs enable - active low
TcsFreq         PIN     1                       ' freq from TCS230
TcsS2           PIN     2                       ' color filter control
TcsS3           PIN     3


' -----[ Constants ]-------------------------------------------------------

Red             CON     0                       ' TCS230 filter selection
Green           CON     1
Blue            CON     2
Clear           CON     3

ScanTime        CON     10                      ' scan time in millisecs
ScaleMax        CON     255                     ' max for scaled values / CHANGED TO 255 FROM 100 - SK

IsOn            CON     0                       ' LED control is active low
IsOff           CON     1

NumColors       CON     7                       ' seven M&M colors
ColorThresh     CON     5                       ' allowable variance

TermChar        CON     0                       ' terminater for strings
StrLen          CON     12                      ' max length of names

' -----[ Variables ]-------------------------------------------------------

filter          VAR     NIB                     ' filter selection
rawColor        VAR     WORD                    ' raw return from TCS230

calRed          VAR     WORD                    ' red calibration
calGrn          VAR     WORD                    ' green calibration
calBlu          VAR     WORD                    ' blue calibration

redVal          VAR     BYTE                    ' red value
grnVal          VAR     BYTE                    ' green value
bluVal          VAR     BYTE                    ' blue value
rgb             VAR     redVal                  ' colors array

inKey           VAR     BYTE                    ' input from user
colIdx          VAR     NIB                     ' color index
rgbIdx          VAR     NIB                     ' rgb index
testVal         VAR     BYTE                    ' test value
eePntr          VAR     WORD                    ' data table pointer
char            VAR     inKey                   ' char to print

RXData		VAR		BYTE	

' -----[ EEPROM Data ]-----------------------------------------------------

' RGB data

Colors          DATA    008, 005, 004           ' brown
                DATA    038, 007, 005           ' red
                DATA    075, 022, 008           ' orange
                DATA    086, 060, 011           ' yellow
                DATA    019, 044, 020           ' green
                DATA    005, 009, 023           ' blue
                DATA    021, 017, 031           ' violet

' Color Names

CN0             DATA    "Brown", 0 
CN1             DATA    "Red", 0
CN2             DATA    "Orange", 0
CN3             DATA    "Yellow", 0
CN4             DATA    "Green", 0
CN5             DATA    "Blue", 0
CN6             DATA    "Violet", 0


' -----[ Initialization ]--------------------------------------------------

Setup:
  TcsLeds = IsOff                               ' start off
  OUTPUT TcSLeds                                ' allow direct control
  GOSUB Calibrate_White                         ' white balance sensor
  'GOSUB Calibrate_Colors                        ' calibrate color table - TURNED OFF CALIBRATION SUBROUTINE -SK


' -----[ Program Code ]----------------------------------------------------

Main:



DO


    GOSUB Read_RGB                              ' scan color
    DEBUG DEC3 redVal,                         ' GOT RID OF COMMAS AND QUOTES
          DEC3 grnVal,                              ' BECAUSE I WANTED JUST DEC VALUES
          DEC3 bluVal                               ' ADJUST TO SUIT YOUR DATA DELIMITING PREFERENCE -SK

    'GOSUB Match_Color                           ' compare scan to table
    'IF (colIdx < NumColors) THEN                ' match was found
      'GOSUB Print_Color                          'I'M NOT USING THE MATCH_COLOR SUBROUTINE-SK
      'DEBUG CR
    'ELSE
      'DEBUG "No match", CR
    'ENDIF 

    PAUSE 1000                                  ' delay between scans
  LOOP
  END


' -----[ Subroutines ]-----------------------------------------------------

' Calibrates "white" to ambient conditions

Calibrate_White:
  DEBUG CLS, "TCS230 White Balance"
  DEBUG CR, CR, "Insert white sample.  Press a key to scan..."
  DEBUGIN inKey
  GOSUB White_Balance
  DEBUG CR, CR, "White balance complete."
  PAUSE 1000
  DEBUG CLS
  RETURN


' Reads "white" and calculates calibration values

White_Balance:
  filter = Red
  GOSUB Read_Color                              ' read raw red
  calRed = ScaleMax * 256 / rawColor            ' calculate red cal
  filter = Green
  GOSUB Read_Color                              ' read raw green
  calGrn = ScaleMax * 256 / rawColor            ' calculate green scale
  filter = Blue
  GOSUB Read_Color                              ' read raw blue
  calBlu = ScaleMax * 256 / rawColor            ' calculate blue scale
  RETURN


' Calibrates color table to ambient conditions

Calibrate_Colors:
  FOR colIdx = 0 TO (NumColors - 1)             ' loop through all colors
    DEBUG CLS, "TCS230 Color Calibration: "
    GOSUB Print_Color
    DEBUG CR, CR, "Insert sample.  Press a key to scan..."
    TcsLeds = IsOn                              ' light up scan area
    DEBUGIN inKey
    GOSUB Read_RGB                              ' scan sample item
    eePntr = Colors + (3 * colIdx)              ' point to table entry
    WRITE eePntr, redVal, grnVal, bluVal        ' save new data
  NEXT
  DEBUG CLS
  RETURN


' Reads selected color from TCS230
' -- takes "filter" as input
' -- returns "rawColor" as output (unscaled color value)

Read_Color: 
  SELECT filter
    CASE Red
      LOW TcsS2
      LOW TcsS3

    CASE Green
      HIGH TcsS2
      HIGH TcsS3

    CASE Blue
      LOW TcsS2
      HIGH TcsS3

    CASE ELSE                                   ' clear -- no filter
      HIGH TcsS2
      LOW TcsS3
  ENDSELECT

  TcsLeds = IsOn                                ' light sample
  COUNT TcsFreq, ScanTime, rawColor             ' return unscaled value
  TcsLeds = IsOff
  RETURN


' Reads and scales RGB colors

Read_RGB:
  filter = Red
  GOSUB Read_Color
  redVal = rawColor */ calRed MAX ScaleMax
  filter = Green
  GOSUB Read_Color
  grnVal = rawColor */ calGrn MAX ScaleMax
  filter = Blue
  GOSUB Read_Color
  bluVal = rawColor */ calBlu MAX ScaleMax
  RETURN


' Compares current color scan with known values in
' table. If match is found, the value of "colIdx"
' will be less than "NumColors"

Match_Color:
  colIdx = 0
  DO WHILE (colIdx < NumColors)                 ' check known colors
    rgbIdx = 0
    DO WHILE (rgbIdx < 3)                       ' compare rgb components
      eePntr = Colors + (colIdx * 3) + rgbIdx   ' point to color table
      READ eePntr, testVal                      ' read known r, g or b
      testVal = ABS(testVal - rgb(rgbIdx))      ' calculate variance
      IF (testVal > ColorThresh) THEN EXIT      ' if out-of-range, next
      rgbIdx = rgbIdx + 1                       ' test next component
    LOOP
    IF (rgbIdx = 3) THEN EXIT                   ' match found  
    colIdx = colIdx + 1                         ' try next color
  LOOP
  RETURN


' Print color name 
' -- takes "colIdx" as input
' -- allow this to fall through to Print_String

Print_Color:
  LOOKUP colIdx, [CN0, CN1, CN2, 
                  CN3, CN4, CN5, CN6], eePntr

' Print a string stored in DATA table
' -- point to first character with "eePntr"

Print_String:
  DO
    READ eePntr, char                           ' reach character
    IF (char = TermChar) THEN EXIT              ' end of string?
    DEBUG char                                  ' no -- print char
    eePntr = eePntr + 1                         ' point to next
  LOOP
  RETURN