File content as of revision 5:d622f8a4a016:

// Conv1 Slave
#include "main.h"

int main()
{
    init();
    while (1) {}
}

void i2cStart(void)
{
    SDA_interrupt.disable_irq();
    char addr = (char)slave.read();
    if (addr & 0x01 == 0x01) { //reading from slave
        char uart_rec2;
        device.putc(DATA_TO_WRITE_CHAR);
        device.putc(addr);
        while(1) {
            device.putc(DATA_TO_READ_CHAR);
            while(1) { // waiting for data byte from conv2
                if(device.readable()) {
                    if (device.getc() == UART_CHAR_INCOMING) {
                        uart_rec2 = device.getc();
                        break;
                    }
                }
            }
            if(!slave.write(uart_rec2)) {
                device.putc(END_OF_TRANSMISSION);
                break;
            }
        }
        slave.read();
    } else {
        count = 0;
        char uart_rec;
        device.putc(DATA_TO_WRITE_CHAR);
        device.putc(addr);
        while(!SDA_state) { //writting to slave
            buffer = (char)slave.read();
            for(int y = 0; y < 1024; y++) {} //some delay required for signal establishment
            if(SDA_state) break;
            device.putc(DATA_TO_WRITE_CHAR);
            device.putc(buffer);

            while(1) { // waiting until confirmation char is received from converter 2
                if(device.readable()) {
                    uart_rec = device.getc();
                    if(uart_rec == UART_CONFIRMATION_CHAR || uart_rec == UART_NON_CONFIRMATION_CHAR)
                        break;
                }
            }
            if (uart_rec == UART_NON_CONFIRMATION_CHAR)
                break;
        }
        device.putc(END_OF_TRANSMISSION);
    }
    SDA_interrupt.enable_irq();
}

void init(void)
{    
    device.baud(921600);
    SDA_interrupt.fall(&on_SDA_falling_slope_interrupt);
}

void on_SDA_falling_slope_interrupt(void)
{
    SDA_interrupt.disable_irq();
    int prev_state = 1;
    int temp_state;
    uint8_t address = 0;
    for (int i = 7; i >= 0; i--) //for every clock cycle in frame
    {
        while(1) //sample CLK line state
        {
            if ((temp_state = SCL_state) == prev_state) 
                continue;
            else
            {
                if (SDA_state == 1) 
                    address |= (0x01 << i); 
                prev_state = temp_state;
                //device.putc((char)SDA_state);
                break;
            }
        }
    }
    
    // now we (probably) know the Slave address, so we can initialize i2c bus
    // and set this Conv as Conv1 and send info to second Conv to act as Conv2
    
    //device.putc(SET_CONV2_FUNCT);
    device.putc(address);
    //init_I2C(address, 100000);
    SDA_interrupt.enable_irq();
}

void init_I2C(char addr, int freq)
{
    SDA_interrupt.fall(&i2cStart);
    slave.address(addr);
    slave.frequency(freq);
}