This page discusses a demo that uses the IIC module on the PIC16F819.
Connect an RS232 via a resistor to a PIC16F819, with SDA and SCL pulled up and you can explore IIC.
Connect other IIC 7 bit devices and send and receive bytes from them.
It is possible to get the chip to talk to itself.
; Uses PIC16F819 ; ; Pull up SDA and SCL pins with 4k7 resistors, ; ; SERIAL PORT CONTROL: ; ; PORT A0 is Serial input ; PORT A0 is serial output ; ; usb gmus-03 USB Serial Adapter ; ; TX D9 Pin 3 -[4k7]----+-----PA0 ; RX D9 Pin 2 ----------/ ; ; GND D9 Pin 5 ---------------- 0V ; ; ; Serial Commands:- ; ; ; w,p,r,g,f,a ; ; ; File Regiters ; <CR>wAADD; write DD to register AA ; <CR>rAA; read AA and output to serial port ; ; EEPROM ; <CR>pAADD; write DD to EEPROM register AA ; <CR>gAA; read EEPROM register AA and output to serial port ; ; PRIPHERALS ; ; IIC master commands to set to slave and master. ; Master is done by code. EEPROM ; ; <CR>iAA; IIC init set Addr = AA ; ; <CR><AA; IIC START , ADDR , set lsb for R/W ; <CR>>; IIC STOP ; <CR>/DD; IIC master writeByte ; <CR>?; IIC master readByte & ACK. If you get ~, SCL is being held low and read has timed out. ; <CR>~; IIC master readByte & NACK. If you get ~, SCL is being held low and read has timed out. ;