Thread: Help With library counter programs

Originally Posted by CommonTater

That might work...

Code:

if (p3.0 == 0 && p3.1 == 1)

...if that zero was an "oh", and that one was an "el"


Quzah.

Originally Posted by CommonTater

Some embedded systems identify bits on hardware ports that way... Can't remember exactly where but I have seen this before.

In any case, even if the variable names are bogus... the concept is right.

Hm...

C and the 8051 - Google Books

Maybe something like that table, column four? C wouldn't let you use a number as a variable name, which is why I mentioned it. But I suppose if you were writing your own hardware specific compiler you could. But I'm guessing it's really just a way to reference it for discussion, rather than an actual variable name.

edit - a few seconds and a search engine confirms my suspicions:

Code:

/*
	Program:Lcd4b.C
	Patchup file:Lcd4ba.c
	Author: Vineet Kulkarni
	Date:06-07-2000
	Modified:07-07-2000
	Language: C + assembly
	LCD test program, to be used with Mini51 evaluation/prototyping board
	LCD connections:
		p2.0 to p2.3 are connected to 4 MSBits of LCD databus
		p2.4 is connected to EN of LCD (1 means LCD selected)
		p2.5 is connected to A0 of LCD (0 means command, 1 means data)
		WR of LCD is connected to Ground, so we can never read LCD status

	This program has functions to initialize LCD and display a
	string on it.
	Here the LCD is port driven and used in 4 bit interface.
*/

They use the .# for reference, but the actual code does not:

Code:

void display_lcd(char arr[32]) {

// displays first 16 characters in the string on line 1 and
// remaining 16 characters on 2nd line
// assumed 16 X 2 display
	unsigned char count, tempchar;

	lcd_cmd(0x80);
	for(count=0;count<16;count++) { // first line
		if(arr[count]) {
			tempchar = arr[count] ;
			lcd_dat(tempchar);
		}
		else return;
	}
	lcd_cmd(0xc0);		//addrs for second line
	for(count=16;count<32;count++) {
		if (arr[count]) {
			tempchar = arr[count] ;
			lcd_dat(tempchar);
		}
		else return;
	}
}

Quzah.

I fiddled with making a C program for this that works on the computer. It works heh. But I do not know how to get it to work with 8051. The biggest problem I am having how do I get the contents of the X and Y variable to display on the LCD? here is the program

Code:

void main(void)
{
int P30; //first photo eye
int P31; //second photo eye
int x=0; //entyer count
int y=0; //exit count
do
	{
printf("\nwhich photo eye broke first? 1 or 2\n");
scanf("%d", &P30);
printf("\nwhich photo eye broke second\n");
scanf("%d", &P31);

//checking to see the order in which the photo eyes are broken the photo eyes will be tied to 
//high so when they go low this will increment the right count based on which photo eye went
//low first
if(P30==1&&P31==2)
			x++;
		else if(P30==2&&P31==1)
			y++;
printf("\n%d people entered\n", x);
printf("\n%d people exited\n", y);
	} while(x>=0);
}

Originally Posted by ssotek

I do not know how to get it to work with 8051. The biggest problem I am having how do I get the contents of the X and Y variable to display on the LCD?

I assume that whoever gave you this assignment also gave you some instructions on the 8051. Go read them. Failing that, use the internet: "displaying on the 8051 lcd" + your search engine of choice = answers.


Quzah.