( CMPS03 I2C
( 1 VCC
( 2 SCL PB0
( 3 SDA PB1
( 9 GND

SCRUB ( COLD
 

DECIMAL
LOOPINDEX BITCNT 0 START 8 END EEWORD
HEX
VARIABLE BITLINE EEWORD       ( temp variable for result
VARIABLE BITSTATUS EEWORD
VARIABLE R/W EEWORD
VARIABLE BYTEOUT EEWORD
VARIABLE BYTEIN  EEWORD


: SCL? PB0 ON? ; EEWORD    ( test if SCL is allowed high, not down by another 
: SCL+ SCL? DROP ; EEWORD  ( actual usage for I2C to see if line released
: SCL- PB0 OFF ; EEWORD    ( I/O turned off

: SDA? PB1 ON? ; EEWORD
: SDA+ SDA? DROP ; EEWORD
: SDA- PB1 OFF ; EEWORD

: I2CSTART    ( sequence to begin i2c comms
  SDA+        ( bring SDA low while SCL is high then SCL low to begin clocking
  SCL+ 
  SDA-
  SCL-
  SDA+ ( LET GO DATA
; EEWORD

: I2CSTOP ( sequence to end i2c comms
  SDA-    ( bring SCL high while SDA is low, then DA high too
  SCL+
  SDA+
; EEWORD

: CLK.
  SCL+
  SCL-
; EEWORD

: CLK.?
  SCL+ ( clock in the ack' bit
  SDA?
  SCL-
; EEWORD

: ACK.?
  SDA+ ( MAKE LINE HIGH SO SLAVE CAN ACK WITH LOW
  CLK.?
  SDA+
; EEWORD

: ACK.!
  SDA-
  CLK.
  SDA+
; EEWORD


: BITLINE>   ( BIT SHIFT OUT
  BITLINE @ 2* DUP BITLINE !
  100 AND 
  IF 
    SDA+
  ELSE
    SDA-
  THEN
  CLK.
  SDA+       ( LET GO
; EEWORD

: >BITLINE   ( BIT SHIFT IN
  CLK.?
  IF 
    1
  ELSE
    0
  THEN
  BITLINE @ 2*
  + BITLINE !
; EEWORD


: I2COUTBYTE
  BITLINE ! 

  BITLINE>

  BITLINE>

  BITLINE>

  BITLINE>

  BITLINE>

  BITLINE>

  BITLINE>

  BITLINE>

  ACK.?

; EEWORD

: I2CINBYTE
  0 BITLINE !

  >BITLINE

  >BITLINE

  >BITLINE

  >BITLINE

  >BITLINE

  >BITLINE

  >BITLINE

  >BITLINE

  BITLINE @
; EEWORD

: READB               ( test word to read all
  I2CSTART
    C0 I2COUTBYTE .
     0 I2COUTBYTE .
  I2CSTART
    C1 I2COUTBYTE .
  I2CINBYTE ACK.! .   ( READ AND SHOW ALL 16 REGISTERS
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE ACK.! .
  I2CINBYTE I2CSTOP .
; EEWORD

: DIR?                 ( 0-FF value from register 1
  I2CSTART
    C0 I2COUTBYTE DROP
     1 I2COUTBYTE DROP
  I2CSTART
    C1 I2COUTBYTE DROP
  I2CINBYTE I2CSTOP .
; EEWORD

: DIRW?                ( 0-EOF value from registers 2, 3
  I2CSTART
    C0 I2COUTBYTE DROP
     2 I2COUTBYTE DROP
  I2CSTART
    C1 I2COUTBYTE DROP
  I2CINBYTE ACK.! ><
  I2CINBYTE I2CSTOP OR .
; EEWORD