help needed for 7 segment display - Electronic Circuits Projects Diagrams Free

mainman · 30th April 2007, 10:55 AM

I'm looking to code a 16f84 PIC chip that makes a seven segment display output H E L P. I've looked all over the internet with no luck. I was wondering if anyone knew any code that would help?

many thanks

**Nigel Goodwin** · 30th April 2007, 11:22 AM

You just need to switch four different patterns to the display, you're unlikely to find EXACTLY what you want, because it's such a strange request - but it's trivial to do.

mabauti · 1st May 2007, 04:00 AM

I think this can be useful to you :
http://www.mikroe.com/en/books/picbook/7_08chapter.htm

ericgibbs · 1st May 2007, 11:21 AM

hi,
If you use the good example that 'mabauti' has posted, you will have to extend the Bcdto7Seg table and pointers, to cover 'HELP'

Gayan Soyza · 1st May 2007, 05:30 PM

Here is the body of the code I wrote for you.The initialize part and the delay you can do.In this example PORTA connecting to common cathodes & segment pins connects to PORTB.
Note that With this simple method you can only show letters.

Code:

;NOTES***********************************************************

;COMMON CATHODE SEGMENTS DISPLAY "HELP"

;COMMON CATHODES SHOULD CONNECT TO PORTA ACORDING TO THIS TABLE

;SEGMENTS STARTING FROM LEFT TO RIGHT

;SEG4	SEG3	SEG2	SEG1
;H	E	L	P
;RA0	RA1	RA2	RA3


;SEGMENT PINS SHOULD CONNECT TO PORTB ACORDING TO THIS TABLE
;SAME PINS LINKS TO OTHER SEGMENT PINS

;SEGMENT A-RB0
;SEGMENT B-RB1
;SEGMENT C-RB2
;SEGMENT D-RB3
;SEGMENT E-RB4
;SEGMENT F-RB5
;SEGMENT G-RB6

;DELAY SHOULD BE ABOUT 10MS

;****************************************************************

HELLO	 MOVLW B'00001'		;TURN ON RA0 & OFF OTHERS
	 MOVWF PORTA
	 MOVLW B'1110011'	;DISPLAY LETTER P
	 MOVWF PORTB
	 CALL  DELAY 
	
	 MOVLW B'00010'		;TURN ON RA1 & OFF OTHERS
	 MOVWF PORTA
	 MOVLW B'0111000'	;DISPLAY LETTER L
	 MOVWF PORTB
	 CALL  DELAY 

	 MOVLW B'00100'		;TURN ON RA2 & OFF OTHERS
	 MOVWF PORTA
	 MOVLW B'1111001'	;DISPLAY LETTER E
	 MOVWF PORTB
	 CALL  DELAY 

	 MOVLW B'01000'		;TURN ON RA3 & OFF OTHERS
	 MOVWF PORTA
	 MOVLW B'1110110'	;DISPLAY LETTER H
	 MOVWF PORTB
	 CALL  DELAY
	 GOTO  HELLO

Mike, K8LH · 1st May 2007, 09:34 PM

Gayan has provided a simple, elegant, intuitive example which should be more than enough to get the OP started.

gramo · 2nd May 2007, 01:57 PM

Code:

Device 16F877

Xtal = 4

Dim Number As Byte
	
Initialization:

	TRISB = %00000000               ' Make PORTB all outputs

	Number = 0                      '
		
Main:
	 
	 Number = 0

	 Repeat                                    ' Create a loop
		  
		 Inc Number                        ' Increment the Number register
		 
		 GoSub Encode_Segment_Display      ' Convert to segment data and display it
		 
		 DelaymS 500                       ' Small delay to slow down counting
		  
	 Until Number = 4                         ' Loop until number = 4, then reset

	 Goto Main                                 ' Loop forever
	 
Encode_Segment_Display:

	SELECT Number
	    CASE 1			
	   		 PORTB = %01110110
	    CASE 2			
			 PORTB = %01111001
	    CASE 3			
	   		 PORTB = %00111000
	    CASE 4			
	   		 PORTB = %01110011
	ENDSELECT
	
	Return

Click here to watch this program/circuit in action

Hope that helps (The circuit shows a "1" - its just a saved piccy on my site, watch the video to see "H E L P" displayed on the segment)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Latest
Problem with LCD code?	spondootre	Micro Controllers	15	29th April 2008 09:15 AM
Design 5 digits LED 7 segment display...(pH meter)!	ayien	Electronic Projects Design/Ideas/Reviews	1	12th January 2007 08:43 AM
microchip application A590 /display is ok now	prosound90	Micro Controllers	20	18th November 2006 09:44 PM
Trouble with seven segment display.	Jeggyman	General Electronics Chat	8	6th June 2004 12:18 AM
Convert Leds to 7 Segment Display	Almazick	General Electronics Chat	21	19th August 2003 07:52 PM

30th April 2007, 10:55 AM	(permalink)
mainman	help needed for 7 segment display I'm looking to code a 16f84 PIC chip that makes a seven segment display output H E L P. I've looked all over the internet with no luck. I was wondering if anyone knew any code that would help? many thanks

30th April 2007, 11:22 AM	(permalink)
Nigel Goodwin	You just need to switch four different patterns to the display, you're unlikely to find EXACTLY what you want, because it's such a strange request - but it's trivial to do. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

1st May 2007, 04:00 AM	(permalink)
mabauti	I think this can be useful to you : http://www.mikroe.com/en/books/picbook/7_08chapter.htm

1st May 2007, 11:21 AM	(permalink)
ericgibbs	hi, If you use the good example that 'mabauti' has posted, you will have to extend the Bcdto7Seg table and pointers, to cover 'HELP' __________________ Eric "Good enough is Perfect" PIC tutorials: Gramo's: www.digital-diy.net/ Bill's: www.blueroomelectronics.com/

1st May 2007, 09:34 PM	(permalink)
Mike, K8LH	Gayan has provided a simple, elegant, intuitive example which should be more than enough to get the OP started.