driver for ftdi 245BM

[csshah]

hi all
I came across an old post of ftdi 245bm driver for ccs. actually i want to communicate with pc using pic 18f8720 and ftdi 245bm. i found the driver for usb from an old post but dont know how to make use of it in order to communicate with PC. here I am pasting that driver if u can tell me how can i use it with VC++ to get some console window for communication.

[#include .... // include CPU specific header and port definitions

#define TxCQsize 64 // Console Tx buffer size
#define RxCQsize 64 // Console Tx buffer size


//; Console Rx Ring Buffer control
byte Rx_HeadC;
byte Rx_TailC;

//; Console Tx Ring Buffer control
byte Tx_HeadC;
byte Tx_TailC;

// Console Tx buffer
byte Tx_BaseC[TxCQsize];

// Console Rx buffer
byte Rx_BaseC[RxCQsize];



void console_putc(char TxChar)
/************************************************************************************************
;
; Subroutine console_putc
;
; Stdout routine (BLOCKING) for putting characters to the console interface.
;
; On Exit:
;
; ***********************************************************************************************/
{
long counter = 65535; // setup counter to prevent lockup on failure of USB

//; test to determine if the USB device is active
if (!bit_test(USB_PwrEn))
{
while ((counter!=0) && bit_test(USB_WRF))
{
counter--;
}
if (Counter)
{
DBus = TxChar; //; write the character to the data bus
bit_set(USB_WR);
DBusDir = 0; //; set data bus to output
bit_clear(USB_WR);
DBusDir = 0xff; //; set data bus to input
}
else
{
// timeout waiting on USB
// .. do something else here such as write to serial port
putc(TxChar);
}
}
else
{
//; USB port not active, do something else like pass control to the async port code
putc(TxChar);
}
}


bit console_kbhit(void)
{
// test to determine if the USB device is active
return ((!bit_test(USB_PwrEn)) && (!bit_test(USB_RDF)));
}

char console_getc(void)
{
char Rx_Char = 0x00;

// test to determine if the USB device is active
// if not active pass exit
if ((!bit_test(USB_PwrEn)) && (!bit_test(USB_RDF)))
{
// here we have a character in the USB controller
DBusDir = 0xFF; // set the data bus to input
bit_clear(USB_RD);
Rx_Char = DBus;
bit_set(USB_RD);
}
return (Rx_Char);
}


void main()
{
init_pic();

//; initialise the I/O lines to the USB controller
bit_set(USB_FLUSH); //; initialise the flush FIFO pin
bit_clear(USB_WR); //; set default WR level
bit_set(USB_RD); //; set default RD level

//; initialise Console receive buffer pointers
Rx_HeadC = 0;
Rx_TailC = 0;

//; initialise Console transmit buffer pointers
Tx_HeadC = 0;
Tx_TailC = 0;

printf(console_putc,"Hello, world\r\n");

//ExecLoop
while (1)
{
// do something
// don't forget to scan the USB device
// note that the FTDI245 has a large input buffer
// there is not need to do a buffer to buffer copy
//
}
}
][/code]

[asmallri]

Here is a slightly enhanced version of the same. It uses a flag to remember if the USB device is in a stalled state to avoid waiting. The FTDI can effectively stall if the windows machine has no application servicing the receive queue for virtual comm port assigned to the FDTI device. In this case the FTDI transmit buffer fills and, unless you have incorporated error handling, the PIC can loop indefinitiely waiting to send to the FTDI chip. Note this problem is a generic problem not specifically an FTDI issue.