Master I2C write to PicSlave Example

[kent_twt4]

Here is an example of using a master Pic to control a slave Pic.  The code uses the I2C MasterI2C.h and SSP_I2C_Picslave.h library's.  As a short term solution, the following subroutine code would need to be copied and pasted into the MasterI2C.h file:

sub I2CWriteTemp(WriteID,command) ;#NR
  Start
  TxI2C(WriteID)  'Device ID write byte
  TxI2C(command)  'Send byte size data
  Stop
end sub

;-----------------------------------------------------------------------------------------;The Master I2C code example:
;-----------------------------------------------------------------------------------------
'Chip model
#chip 16f877A,20
#include <MasterI2C.h>

'Setup 4 bit LCD
#define LCD_IO 4
#define LCD_DB4 PORTD.4
#define LCD_DB5 PORTD.5
#define LCD_DB6 PORTD.6
#define LCD_DB7 PORTD.7
#define LCD_RS PORTD.1
#define LCD_RW PORTD.2
#define LCD_Enable PORTD.3
Dir PortD out

'Setup Master I2C
#define PicSlaveWrite b'00110010'
#define PicSlaveRead  b'00110011'
#define BufferLen 8
#define ClockValue b'00110001'  ;ClockValue or SSPADD = (FOSC / (4 * Baud)) - 1   
Dir PortC.3 In  'SCL Port Pin
Dir PortC.4 In  'SDA Port Pin
InitI2C

Main:
cls
wait 25 10ms  ;Blip screen to verify refreshed data
For index = 1 to BufferLen
I2CData = index
I2CWriteTemp(PicSlaveWrite,I2CData)  ;Write data to slave
LCDInt(I2CData):Print " "  ;Show data being sent to slave
wait 2 s
Next
goto Main

;-----------------------------------------------------------------------------------------
;The slave I2C example:
;-----------------------------------------------------------------------------------------
'Chip model
#chip 16f88,20

;Setup SSP module
#include <SSP_I2C_PicSlave.h>
#define PicSlave b'00110010'  ;Set Pic Slave I2C address
#define BufferLen 1  ;How many bytes to receive
Dim RxBuffer(RxBufferSize)
InitSSP  ;Setup SSP registers and enable interrupts
Dir PortB.1 in  ;SDA pin for 16f88
Dir PortB.4 in  ;SCL pin for 16f88

;Receive test Byte from master
;And send out lower nibble on Slave Led's
Dir PortB.0 out
Dir PortB.2 out
Dir PortB.3 out
Dir PortB.5 out

Main:
TestLed = RxBuffer(1)  ;Receive Byte from Master
Rotate TestLed Right
PortB.0 = Status.C 
Rotate TestLed Right
PortB.2 = Status.C 
Rotate TestLed Right
PortB.3 = Status.C 
Rotate TestLed Right
PortB.5 = Status.C 
goto Main

[kent_twt4]

Most unfortunately, the call for the interrupt subroutine did not make it to the (pic) slave I2C example.  Insert the interrupt call as below.  Also, the pic slave BufferLen is only working currently with one byte transfers (i.e. #define BufferLen 1), per example.  Due not confuse the BufferLen in the master code, that was an inappropriate/confusing variable designation.

'Insert missing interrupt call subroutine for pic slave
Main:
Interrupt
TestLed = RxBuffer(1) ;Receive Byte from Master
Rotate TestLed Right
PortB.0 = Status.C 
Rotate TestLed Right
PortB.2 = Status.C 
Rotate TestLed Right
PortB.3 = Status.C 
Rotate TestLed Right
PortB.5 = Status.C 
goto Main