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7 segment display problem ATMEL

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stepan89

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Hello everyone,

I am a very beginner in microcontrolers. I need to program a 7-segment display - I need to show 3 (or more) digit number and move it from the first display to the last. I have got 8 seven-segment displays. I uploaded an image for better imagination, what I need. I should be really easy, but I'm stucked with this. So any help would be appreciated.

I wrote a program that ALMOST works - I want it to show like this: 1. show first digit, 2. show first and second digit, 3. show first, second and third digit 4. move along the 8 displays till eighth display, where it should do the same but vice versa - show only 2 digit, show 1 digit, show 0 digit ....

I have attached simple illustration.

Here's the part of my code:

Code: 
// Want to display 3 digit number e.g. 120
// BCD function convert numbers to hexadecimal
// PORTB - the display
// PORTC - segments on display

DDRC = 255;
DDRB = 255;
char original = 1;

while (1)
{
	PORTB = 1;  // start on display 1

	for (int i = 1; i <= 8; i++)
	{					
		PORTB = PORTB * 2;  // second, third... display ... 1,2,4,8,16,32,64,128
		
		if (i == 1)         // in first step I want to be on display 1, next on 2, 4, 8 ...
		{
			original = 1;
			PORTB = 1;
		}			
		else
			original = PORTB;
		
		
		
		for (int j = 1; j < 20; j++)
		{		
			PORTC = BCD(1);   // shows 1
			delay_ms(5);
	
			PORTB = PORTB >> 1; // display next to the first 
			PORTC = BCD(2);  // shows 2
			delay_ms(5);
	
			PORTB = PORTB >> 1;  // display next to the second
			PORTC = BCD(0);  // shows 0
			delay_ms(5);	
			
			PORTB = original;   // resets the position of PORTB, 20 times it would shift more than need			
		}                           // so if PORTB is e.g. 8, then PORTB 4 and PORTB 2 shows number		
				
	}
}

}

26_1336201545.jpg


Thank you very much !
 

Attachments

  • 7segment.jpg
    7segment.jpg
    27 KB · Views: 128

Hello, It would help if you have a wiring diagram, but If I got it right, this should work... I wouldn't do it like this, but I've tried not to change too much your code.. Otherwise you would loose all the fun on figure out the rest by your self :)

between other problems your where having PORTB overflow

Code: 
// Want to display 3 digit number e.g. 120
// BCD function convert numbers to hexadecimal
// PORTB - the display
// PORTC - segments on display

DDRC = 255;
DDRB = 255;
[B]int[/B] original = 1;  // start on display 1

while (1)
{
	for (int i = 1; i <= [B]10[/B]; i++)
	{					
		
		for (int j = 1; j < 20; j++)
		{	
	                [B]PORTB = (char) original ;[/B]
			PORTC = BCD(1);   // shows 1
			delay_ms(5);
	
			PORTB = [B](char)(original >> 1)[/B]; // display next to the first 
			PORTC = BCD(2);  // shows 2
			delay_ms(5);
	
			PORTB =[B](char)(original >> 2)[/B];  // display next to the second
			PORTC = BCD(0);  // shows 0
			delay_ms(5);	
			
					
		}                           // so if PORTB is e.g. 8, then PORTB 4 and PORTB 2 shows number		
	
               [B] original = original << 1; [/B] // second, third... display ... 1,2,4,8,16,32,64,128
		
	}
}

}
 
Last edited:
To: mgate

Thanks a lot! That's a pity I can't try it, I must wait till friday, I haven't got microcontroler at home :)

---------- Post added at 12:25 ---------- Previous post was at 12:11 ----------

OK... i think I understand. But if I would like to run it over and over again, from left to right, I have to add /original = 1;/ in the beginning of program, right after while (1), am I right?
 

I hope its working now... Anyway if it is still not working, or if you need help for adding a bigger message, just post again your issues :) .. I guess you will need to be patient ..

---------- Post added at 11:31 ---------- Previous post was at 11:27 ----------

OK... i think I understand. But if I would like to run it over and over again, from left to right, I have to add /original = 1;/ in the beginning of program, right after while (1), am I right?
Click to expand...

Yes, That would do the trick :)
 

Thanks again!
I want to "upgrade" it little more. I'd like to move a counter (0 - 59, lets say it increments every second) - and I want it to move along the displays like the number "120" before. Every second it changes and moves ... next second change and move ... round and round ...

I tried to put the two algorithms together. Can you please give a comment? I can't try the algorithm now, so it is really hard to say if its ok or a really stupidity :)

Counter algorithm:
Code: 
		for (int i = 0; i < 60; i++)
		{	
			for (int j = 0; j < 100; j++)  // 100 * 10 ms = 1 second
			{
				PORTB = 1;	
				PORTC = BCD(i%10);  // displays numbers
				delay_ms(5);
			
				PORTB = 2;
				PORTC = BCD(i/10);   // displays decades
				delay_ms(5);

And if I put it together with the "moving" algorithm, I got this:

Code: 
int original = 1;
int counter = 1;

while (1) {	

		for (int i = 0; i < [B]60[/B]; i++)   // I changed to 60 - I need it (the 60) for the clock algorithm in the second for loop
		{	
			for (int j = 0; j < 100; j++)  // 100 * 10 ms = 1 second
			{
				PORTB = (char) original ;	
				PORTC = BCD(i%10);    // displays numbers
				delay_ms(5);
			
				PORTB = (char)(original >> 1) ;
				PORTC = BCD(i/10);   // displays decades
				delay_ms(5);						
			}

			counter++;  // every second counter increments
			
			if (counter == 10)  // if there were already 9 moves - end of displays, and this is the 10th move 
			{
			  counter = 1;   // reset counter
			  original = 1;  // go to the beginning - position 1 (on the right)
			}
			
			original = original << 1;  // every second move one position left
		}

So if you be so kind and tell me, what you mean about it :)
Thank you!
 

I think it might work as long as you check if is the end of the display on the beginning of the main for loop... because of the interaction with the ( original <=1).

Code: 
int original = 1;
int counter = 1;

while (1) {	

		for (int i = 0; i < 60; i++)   // I changed to 60 - I need it (the 60) for the clock algorithm in the second for loop
		{	
			if (counter == 10)  // if there were already 9 moves - end of displays, and this is the 10th move 
			{
			  counter = 1;   // reset counter
			  original = 1;  // go to the beginning - position 1 (on the right)
			}

			for (int j = 0; j < 100; j++)  // 100 * 10 ms = 1 second
			{
				PORTB = (char) original ;	
				PORTC = BCD(i%10);    // displays numbers
				delay_ms(5);
			
				PORTB = (char)(original >> 1) ;
				PORTC = BCD(i/10);   // displays decades
				delay_ms(5);						
			}

			counter++;  // every second counter increments

			original = original << 1;  // every second move one position left
		}
 

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