Code:
//Wireless.c
//Third Year Project
//Written by G. Woodhead, with help from www.cprogramming.com and www.asciitable.com
//12/02/08
//
#include <stdio.h>
#include <conio.h>
#include <string.h>
#include <windows.h>
//
//global constants declarations
#define OutPort 0x378 //port to output data
#define InPort 0x379 //port to receive data
#define Control 0x37A //port to control devices
#define Tx 0 //Transmitter
#define Rx 1 //Receiver
#define clockR 3 //Receiver + clock pulse
#define load 4 //load AND gates of PISO shift registers
#define clockT 8 //Transmitter + clock pulse
#define start 0x80 //start bit
//Function prototype declarations
int Input_keyboard (void);
int Transmit (void);
int Receive (void);
int Display (const int);
/* Definitions in the build of inpout32.dll are:
short _stdcall Inp32(short PortAddress);
void _stdcall Out32(short PortAddress, short data);
prototype (function typedef) for DLL function Inp32: */
typedef short _stdcall (*inpfuncPtr)(short portaddr);
typedef void _stdcall (*oupfuncPtr)(short portaddr, short datum);
char buf[BUFSIZ]; //string to hold keyboard input
char *p; //pointer to string holding keyboard input
//array to hold hex equivalents of ASCII input from keyboard
int hex [63] = {0x20, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x41, 0x42, 0x43, 0x44, 0x45,
0x46, 0x47 ,0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55,
0x56, 0x57, 0x58, 0x59, 0x5A, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B,
0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A};
//string to hold ASCII codes
char ascii [63] = " 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
int main(void)
{
int signal = 0;
int data = 0;
int a = 0;
HINSTANCE hLib;
inpfuncPtr inp32;
oupfuncPtr oup32;
hLib = LoadLibrary("inpout32.dll"); // Load the library
// get the address of the function
inp32 = (inpfuncPtr) GetProcAddress(hLib, "Inp32");
oup32 = (oupfuncPtr) GetProcAddress(hLib, "Out32");
while (a < 100000) //run for a while
{
while (!kbhit()) //while no keyboard input
{
signal = (inp32) (InPort); //check for start bit
signal = (signal & 0x08);
if (signal == 0x08)
{
data = Receive(); //read in data
Display (data) ; //display received text on screen
}
}
Input_keyboard(); //call function to read text from keyboard
(oup32) (Control, Tx); //select transmitter
Transmit(); //call function to transmit text
a++; //increment a
}
FreeLibrary(hLib);
return 0;
}
//==========================================================================================================================================================
//Function: Input_keyboard - to get data from keyboard
int Input_keyboard (void)
{
printf("Please enter a line of text, using only alphanumeric keys and the spacebar, max %d characters\n", sizeof(buf)); //read in text from keyboard
fgets(buf, sizeof(buf), stdin);
if ((p = strchr(buf, '\n')) != NULL) //if there is a 'newline' character at the end of buf, change it to a full stop
{
*p = '.';
}
return 0;
}
//==========================================================================================================================================================
//Function: Transmit - send data from keyboard buffer to parallel port for transmission and control 8-bit output shift register
int Transmit (void)
{
HINSTANCE hLib;
inpfuncPtr inp32;
oupfuncPtr oup32;
hLib = LoadLibrary("inpout32.dll"); // Load the library
// get the address of the function
inp32 = (inpfuncPtr) GetProcAddress(hLib, "Inp32");
oup32 = (oupfuncPtr) GetProcAddress(hLib, "Out32");
int b = 0;
int c = 0;
int d = 0;
int e = 0;
char character;
for (e = 0; e < BUFSIZ; e++)
{
(oup32) (OutPort, start); //send start bit
(oup32) (Control, load); //load flip-flops
(oup32) (Control, clockT); //send transmitter clock output high
sleep (1); //wait 1ms
(oup32) (Control, 0); //send transmitter clock output low
sleep (1); //wait 1ms
character = buf[d]; //get next character from string
if (character == '.')
{
break;
}
for (c = 0; c < 63; c++)
{
if (character == ascii[c])
{
(oup32) (OutPort, hex[c]);
break;
}
}
d++;
(oup32) (Control, load);
for (b = 0; b < 8; b++)
{
(oup32) (Control, clockT);
sleep (1);
(oup32) (Control, 0);
sleep (1);
}
}
return 0;
}
//==========================================================================================================================================================
//Function: Receive - read in data from parallel port and control 4-bit input shift register
int Receive (void)
{
HINSTANCE hLib;
inpfuncPtr inp32;
oupfuncPtr oup32;
hLib = LoadLibrary("inpout32.dll"); //Load the library
//get the address of the function
inp32 = (inpfuncPtr) GetProcAddress(hLib, "Inp32");
oup32 = (oupfuncPtr) GetProcAddress(hLib, "Out32");
int nibble_L = 0;
int nibble_H = 0;
int byte = 0;
int f = 0;
int g = 0;
for(f = 0; f < 4; f++) //clock shift register 4 times to receive 1 nibble
{
(oup32) (Control, clockR); //send clock output high
sleep (1); //wait 1ms
(oup32) (Control, Rx); //send clock output low
sleep (1); //wait 1ms
}
nibble_L = (inp32) (InPort); //read in lower nibble of current character
nibble_L = nibble_L >> 4; //shift right 4 times since nibble read in from upper 4 lines of input port
for (g = 0; g > 4; g++) //clock shift register 4 times to receive 1 nibble
{
(oup32) (Control, clockR); //send clock output high
sleep (1); //wait 1ms
(oup32) (Control, Rx); //send clock output low
sleep (1); //wait 1ms
}
nibble_H = (inp32) (InPort); //read in upper nibble of current character
byte = (nibble_H & 0xF0) | (nibble_L & 0x0F); //form byte from upper and lower nibbles
return byte;
}
//==========================================================================================================================================================
//Function: Display - convert received binary data to ASCII and display on screen
int Display (const int value)
{
int h;
for (h = 0; h < 63; h++)
{
if (value == hex[h]) //find code in hex array that corresponds to received code
{
printf ("%s", ascii[h]); //print ASCII equivalent of received code to screen
break; //exit from loop when correct code is found
}
}
return 0;
}
I've no clue what I could've done wrong, so any help would be much appreciated
Parallel Port I/O in Windows XP - my program crashes when I run it
