Stuck making part of my code work for testing input

Hi everyone, I am new to the forums but not new to the site.

I have this little project for school that we are using our microcontroller boards with.

The project was to take the code given to us (95% of what you see here) that was an odd and even program, to modify it so that 'e' will turn it on, and 'd' will disable it.

I got that part working initially, but in the last step we had to check so that only numbers 0-9, 'e', and d are accepted.

My instructor is known for lots of bad ways of coding, like the while(1) loops, so don't eat me up for those.

I started with a error function (now commented out), that I replaced the character input with at first, but it was giving me problems so I tried making it work just inside the main function.

its telling me that the while(character == "1"... is always true as one of the compile errors along with the while loop.

I look at my code and still think its right. If anything other then d is entered, it should test the odd/even if a numbered is entered, or loop back and ask to enter another number if a false character is given. D should disable it with the else if statement.

Can you help me please, thanks

Code:

/*	Serial Communication exercise on the Axiom CME11E9 EVBU and PC.	        */
/*	A character is entered on the keyboard in terminal mode and it    		        */
/*	is returned to the terminal by the EVB over COM1 with a message		        */
/* 	stating whether it is even or odd and prompting another entry. 		       	        */
/*									    	        */ 
/****************************************************************************/
/*   				Includes (libraries)	      	    		         */
/****************************************************************************/
#include <hidef.h>
/****************************************************************************/
/*   				  Definitions					         */
/****************************************************************************/
#define	baud *(volatile unsigned char *)0x102B		/* baud rate reg. 		*/
#define	sccr1 *(volatile unsigned char *)0x102C		/* sci cont. reg. 1 		*/
#define	sccr2 *(volatile unsigned char *)0x102D		/* sci cont. reg. 2	 	*/
#define	scsr  *(volatile unsigned char *)0x102E		/* sci status reg.  		*/
#define	scdat *(volatile unsigned char *)0x102F		/* sci data reg.   		*/
#define tdre 0x80					/* transmit mask bit	*/
#define rdrf 0x20					/* receive mask bit 	*/
/*****************************************************************************/
/*   		         Declarations (variables and function prototypes)		           */
/*****************************************************************************/	 	
char input(void);
void onsci(void);
/*void error(void);*/
void output(char);
void outcrlf(void);  
void outstr(char *strg);
char Msg1[] = "Enter a number...";
char Msg2[] = "Enter another number..";
char Msg3[] = "... is an odd number";
char Msg4[] = "... is an even number";
char Msg5[] = "The Evaluator Is Off, Press 'e' To Enable It";
char Msg6[] = "The Evaluator Is On, Press 'd' To Disable It";
char Msg7[] = "You entered an invalid character, please try again!";
char character;
/*****************************************************************************/
/*   					Main				  	           */
/*****************************************************************************/
void main(void) 
{			
 EnableInterrupts;
 onsci();
 outstr(Msg5);
 outcrlf();
 while(1)
  {
   character = input();
   if (character == 'e')
  		{
  		outstr(Msg6);
 		outcrlf();
  		outstr(Msg1);
  		outcrlf();
  
  while(character != 'd')
  	{
   	character = input();
   	output(character);
   	if (character == '0' || '1' || '2' || '3' || '4' || '5'|| '6' || '7' || '8' || '9')
   		{
   		if ((character & 0x01) == 0 )
   		{
   		outstr(Msg4);
   		} 
  	    else
  	    {
  	    outstr(Msg3);
  	    }
  	outcrlf();
  	outstr(Msg2);
  	outcrlf();
  	outcrlf();
   		}
	}
	}
	else if (character = 'd')
	{
	main();
	}
	
}   
}  			   

/****************************************************************************/

/****************************************************************************/
/*   				Locally Defined Functions			        */
/****************************************************************************/

/*void error(void)
{

character = input();
while(character != '1' || '2' || '3' || '4' || '5'|| '6' || '7' || '8' || '9' || 'e' || 'd') 
{
outstr(Msg7);
outcrlf();
character = input();
}

}
*/

/****************************************************************************/
void outstr(char *strg)				            /*  Output a string of characters   */
{ 						              /*  String ends in NULL             */
	 char character;				    /*  Exits loop when onechar = NULL  */
     while (character = *strg)
     {
      output(character);
      *strg++;
     }
}

/****************************************************************************/

char input(void)			   		          /*  Read a character from the sci    */
{							/*  wait for rx data then get it     */
 while ((scsr & rdrf) == 0 ){};
 return scdat;		 	      		   				
}

/****************************************************************************/

void onsci(void)			            /*  Initialize SCI for 9600 baud with 8 MHz xtal.    */
{
 baud  = 0x30;
 sccr1 = 0x00;
 sccr2 = 0x0C;
}

/****************************************************************************/

void output(char character)		  		            /* output one character  */
{						       /* wait for tx data reg. empty, then   */ 
 while ((scsr & tdre) == 0){};
 scdat = (character & 0x7F); 	      		      /* clear MSB (parity bit) and send.    */
}

/****************************************************************************/

void outcrlf(void)  	  		 	 /* output a carriage return and line feed  */
{			 
 output(0x0D);
 output(0x0A);
}

/****************************************************************************/
/*   				   End of module.				        */
/****************************************************************************/

> if (character == '0' || '1'
This should be
if (character == '0' || character == '1'

such a simple mistake, I should have picked up on that.

Thanks my friend

I got it partially working, but I it was kind of messy. So I reorganized the code, but haven't got it working since.

I've tried in the numcheck function

Code:

while(character !='1' || .... character !='9' || character !='d')

also tried with converting it to decimal using

Code:

character = character - 48;

then using 

while((0 > character > 10) || character !='d')

I then resorted to this, still no luck. The program will recognize the d to disalble the program now, but still gives invalid character for anything else.

Code:

/*	Serial Communication exercise on the Axiom CME11E9 EVBU and PC.	        */
/*	A character is entered on the keyboard in terminal mode and it    		        */
/*	is returned to the terminal by the EVB over COM1 with a message		        */
/* 	stating whether it is even or odd and prompting another entry. 		       	        */
/*									    	        */ 
/****************************************************************************/
/*   				Includes (libraries)	      	    		         */
/****************************************************************************/
#include <hidef.h>
/****************************************************************************/
/*   				  Definitions					         */
/****************************************************************************/
#define	baud *(volatile unsigned char *)0x102B		/* baud rate reg. 		*/
#define	sccr1 *(volatile unsigned char *)0x102C		/* sci cont. reg. 1 		*/
#define	sccr2 *(volatile unsigned char *)0x102D		/* sci cont. reg. 2	 	*/
#define	scsr  *(volatile unsigned char *)0x102E		/* sci status reg.  		*/
#define	scdat *(volatile unsigned char *)0x102F		/* sci data reg.   		*/
#define tdre 0x80					/* transmit mask bit	*/
#define rdrf 0x20					/* receive mask bit 	*/
/*****************************************************************************/
/*   		         Declarations (variables and function prototypes)		           */
/*****************************************************************************/	 	
char input(void);
void onsci(void);
void numcheck(void);
void oncheck(void);
void output(char);
void outcrlf(void);  
void outstr(char *strg);
char Msg1[] = "Enter a number...";
char Msg2[] = "Enter another number..";
char Msg3[] = "... is an odd number";
char Msg4[] = "... is an even number";
char Msg5[] = "The Evaluator Is Off, Press 'e' To Enable It";
char Msg6[] = "The Evaluator Is On, Press 'd' To Disable It";
char Msg7[] = "You entered an invalid character, please try again!";
char character;
/*****************************************************************************/
/*   					Main				  	           */
/*****************************************************************************/
void main(void) 
{			
 EnableInterrupts;
 onsci();
 outstr(Msg5);
 outcrlf();
 oncheck();

while(1)
  {
  outstr(Msg6);
  outcrlf();
  outstr(Msg1);
  outcrlf();
  
  while(1)
  	{
   	numcheck();	
   	output(character);
   	if (character !='d')
   		{
   			if ((character & 0x01) == 0 )
   			{
   			outstr(Msg4);
   			} 
  	  	    else
  	    	{
  	   		outstr(Msg3);
  	   	    }
  		outcrlf();
  		outstr(Msg2);
  		outcrlf();
  		outcrlf();
   		}
	else
	{
	outcrlf();
	main();
	}
	
}
}   
}  			   

/****************************************************************************/

/****************************************************************************/
/*   				Locally Defined Functions			        */
/****************************************************************************/

void oncheck(void)
{

character = input();
while(character != 'e') 
{
outstr(Msg7);
outcrlf();
character = input();
}

}


void numcheck(void)
{

character = input();
character = character -48;
while((0 > character > 9) || character != 'd') 
{
outstr(Msg7);
outcrlf();
character = input();
}

}

/****************************************************************************/
void outstr(char *strg)				            /*  Output a string of characters   */
{ 						              /*  String ends in NULL             */
	 char character;				    /*  Exits loop when onechar = NULL  */
     while (character = *strg)
     {
      output(character);
      *strg++;
     }
}

/****************************************************************************/

char input(void)			   		          /*  Read a character from the sci    */
{							/*  wait for rx data then get it     */
 while ((scsr & rdrf) == 0 ){};
 return scdat;		 	      		   				
}

/****************************************************************************/

void onsci(void)			            /*  Initialize SCI for 9600 baud with 8 MHz xtal.    */
{
 baud  = 0x30;
 sccr1 = 0x00;
 sccr2 = 0x0C;
}

/****************************************************************************/

void output(char character)		  		            /* output one character  */
{						       /* wait for tx data reg. empty, then   */ 
 while ((scsr & tdre) == 0){};
 scdat = (character & 0x7F); 	      		      /* clear MSB (parity bit) and send.    */
}

/****************************************************************************/

void outcrlf(void)  	  		 	 /* output a carriage return and line feed  */
{			 
 output(0x0D);
 output(0x0A);
}

/****************************************************************************/
/*   				   End of module.				        */
/****************************************************************************/

0 > whatever > 10 is valid C, but isn't what you want it to be (and it wouldn't be what you wanted it to be even if the signs were the other way around). 0 > whatever is done first, giving either 0 or 1; this result is then compared > 10, which is always false. Just like you needed || to check two conditions above, you need an operator to check two conditions here.

Your code is hard to follow, because of poor indentation.
SourceForge.net: Indentation - cpwiki

And your recursive call to main() is a real killer, if you're running this on a embedded chip with a very limited amount of stack space. What's even more odd is that you have two nested while(1) loops.

I suggest using switch/case construct for the menu (the code that decides what to do based on input character).
And, I agree with Salem that calling main() recursively is very bad.

I suggest making a function called menu() that displays the menu and returns the option selected.
Note: It is also common to have a function displayMenu() to show the menu called from menu(); but, you code seems to not really be giving the user a menu. But, other than that it is acting like a menu.

Tim S.