Question

This code doesn’t send data through the UART when I connect two Board-DE2 with a COM wire. I don’t understand why it isn’t operating. What’s wrong?

#define RS232_UART_DATA ((volatile int*) 0x10001010)
#define RS232_UART_CONTROL ((volatile int*) (0x10001010+4))

int main()
{
    unsigned char hwld[] = {'H','e','l','l','o',' ','W','o','r','l','d','\0'};
    unsigned char *pOutput;

    pOutput = hwld;
    while(*pOutput) //strings in C are zero terminated
    {
        //if room in output buffer
        if((*RS232_UART_CONTROL)&0xffff0000  ) 
        {
            //then write the next character
            *RS232_UART_DATA = (*pOutput++); 
        }
    }
}

Answer 1

Could you be more specific about “connect two Board-DE2 by Com wire”? Do you want two DE2 Boards to communicate with each other? According to the web link provided by @HansPassant above, you’re supposed to connect the DE2 Board to a PC that runs TeraTerm. Try this setup first and make sure you enter the correct COM port settings in TeraTerm as mentioned on the webpage.