I2C Slave with a PIC

[DanPBP]

Sure! Let me know if you need anything else

Master 16f877 - External 4Mhz Crystal:

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' Master
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DEFINE OSC 4

'OPTION_REG.7 = 0

ADCON1 = 7

'------------------------------------------------------------------------------

DEFINE I2C_SLOW 1

TRISB.5 = 1
TRISB.7 = 1

'------------------------------------------------------------------------------

scl VAR PORTB.5		' i2c clock input
sda VAR PORTB.7     ' i2c data input

'------------------------------------------------------------------------------

I2Caddress VAR BYTE

valor VAR BYTE

'------------------------------------------------------------------------------

' Set LCD Data port
DEFINE LCD_DREG PORTD
' Set starting Data BIT (0 OR 4) IF 4-BIT bus
DEFINE LCD_DBIT 4
' Set LCD Register Select port
DEFINE LCD_RSREG PORTC
' Set LCD Register Select BIT
DEFINE LCD_RSBIT 6
' Set LCD Enable port
DEFINE LCD_EREG PORTC
' Set LCD Enable BIT
DEFINE LCD_EBIT 7
' Set LCD bus size (4 OR 8 bits)
DEFINE LCD_BITS 4
' Set number of lines ON LCD
DEFINE LCD_LINES 2
' Set command delay time in us
DEFINE LCD_COMMANDUS 2000
' Set Data delay time in us
DEFINE LCD_DATAUS 50

'------------------------------------------------------------------------------

Pause 500       ' Wait for LCD to startup
LCDOut $fe, 1
LCDOut $fe, "Daniel"
Pause 500       ' Wait for LCD to startup

valor = 0

'------------------------------------------------------------------------------

main:
      I2Caddress = $3

      LCDOut $fe, 1
      LCDOut "Writting 1 - LED ON..."
      Pause 500

      I2CWrite SDA, SCL, I2Caddress, [6], bogus ' Write offset to slave
      Pause 500

      LCDOut $fe, 1
      LCDOut "Writting 1 - LED OFF..."
      Pause 500

      I2CWrite SDA, SCL, I2Caddress, [8], bogus ' Write to slave
      Pause 500

      LCDOut $fe, 1
      LCDOut "Reading 1..."
      Pause 500

      I2CRead SDA, SCL, I2Caddress, [valor], bogus ' Read from slave
      LCDOut $fe, 1
      LCDOut "Value: ", DEC valor
      Pause 500

      '--------

      I2Caddress = $5

      LCDOut $fe, 1
      LCDOut "Writting 2 - LED ON..."
      Pause 500

      I2CWrite SDA, SCL, I2Caddress, [4], bogus ' Write to slave
      Pause 500

      LCDOut $fe, 1
      LCDOut "Writting 2 - LED OFF..."
      Pause 500

      I2CWrite SDA, SCL, I2Caddress, [10], bogus ' Write to slave
      Pause 500

      LCDOut $fe, 1
      LCDOut "Reading 2..."
      Pause 500

      I2CRead SDA, SCL, I2Caddress, [valor], bogus ' Read from slave
      LCDOut $fe, 1
      LCDOut "Value: ", DEC valor
      Pause 500

      '--------

      GoTo main       ' Do it forever

'-------------------------------------------------------------------------------

bogus:
		LCDOut $fe,1, "Time out"	' I2C command timed out
		Pause 500

		GoTo main

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End

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