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Clocking a HCF4015B with a pic16f628a

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be80be

be80be

Well-Known Member
Shifting a HCF4015B with a pic16f628a for 7x 15 led Matrix

I'm trying to use a 4015 shift register to scroll 3 5x7 led blocks. What I have done right now is set up the 4015 with 8 leds to get it to scroll right I don't think I have the clock right
Code: 
list      p=16f628A           ; list directive to define processor
	#include <p16F628A.inc>       ; processor specific variable definitions
   
	errorlevel  -302              ; suppress message 302 from list file

	__CONFIG   _CP_OFF & _DATA_CP_OFF & _LVP_OFF & _BOREN_OFF & _MCLRE_ON & _WDT_OFF & _PWRTE_ON & _INTOSC_OSC_NOCLKOUT 

; '__CONFIG' directive is used to embed configuration word within .asm file.
; The lables following the directive are located in the respective .inc file.
; See data sheet for additional information on configuration word settings.
        
	cblock	0x20			;Ram address
	TX				;the 4015
	CountSPI
	endc 

	#define		Data PORTA,0	;hardware
	#define		Clock PORTA,1
	
	org	0x0000			;reset
	goto	Main			
	org	0x04			;interrupt vector
	goto	Main			;no interrupts
	include "HC40015.inc"	
Main					;main program

	movlw	0x07
	movwf	CMCON			;turn comparators off (make it like a 16F84)
	banksel TRISA
	movlw	b'00011000'		;initializing porta
	movwf	TRISA
	banksel	PORTA
	clrf 	PORTA
	movlw 	0xcb			;fill tx buffer
	movwf	TX
	HC40015 TX, CountSPI
Loop
	goto Loop			;hang out here


	END                       	; directive 'end of program'
and this is the macro
Code: 
HC4015 macro Var,Var1
	
	Local 	Loop		;label
	movlw	.8		;eight bits to send
	movwf	Var1		
Loop
	rlf	Var,f		;rotate Var to the left

	btfss 	STATUS,C	;carry = 1 ?
	bcf	Data		;if not set line to 0
	[COLOR="Red"]
       btfsc	STATUS,C	;is carry = 0 ?
	bsf	Data		;if not set, set data line to 1
        [/COLOR]
	bsf	Clock		; generate 1 clock
	nop
	bcf	Clock
	
	decfsz	Var1,f		;bits been sent ?
	goto	Loop		;if not repeat

	endm
and here is how I have it hooked up. I think I found what I did wrong
I left the part in red out lol should this work thanks for any help
Burt
 

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Last edited:
Ok this is the deal if i send out 0xff it should turn on all 8 leds it just turns on the first 4 all
8 leds will come on if I do it with a switch. And would I not have to reset it before i send new code?
 
The 4015 is two separate 4 bit shift registers. You need to connect them up separately (2 clock pins, namely #1 and #9) and if you're shifting right make sure you move the "right-hand" one before the "left-hand" one,

1234 5678
move the right one
1234 -567
move the left one
-123 4567
grab the new data
n123 4567

otherwise "4" would overwrite "5" before you had a chance to save it.

Also:

Code: 
btfss 	STATUS,C	;carry = 1 ?
bcf	Data		;if not set line to 0
	
btfsc	STATUS,C	;is carry = 0 ?
bsf	Data		;if not set, set data line to 1

You can save a line by doing this,
Code: 
bsf	Data		;set data line to 1
btfss 	STATUS,C	;carry = 1 ?
bcf	Data		;if not set line to 0

i.e. assume the data is 1 and correct it if it isn't.

Hope that helps,

ahydra
 
The data sheet said you can hook them up with the same clock line. That you feed Q4a to data b and clock a to clock b
 
Last edited:
I think I'll change chips to 74ls164. the 4015 don't work to good
 
be80be said:
The data sheet said you can hook them up with the same clock line. That you feed Q4a to data b and clock a to clock b
Click to expand...

Interesting. I can't remember whether I tried that when I built a similar circuit, but I've never had any problems when connecting the two clocks separately and clocking them in the right order.

ahydra
 
What I think is happening is the clock is wrong see when it loads the first data in it doesn't shift it right and when I check the clock line its low that's why ask if I had it right. The clock should be faster then the data like 2 to 1. I no the data is going out right. Some thing is making my clock line low.
 
I can scroll 4 pins of the 4015 but not all 8 here my new code
Code: 
list      p=16f628A           ; list directive to define processor
	#include <p16F628A.inc>       ; processor specific variable definitions
   
	errorlevel  -302              ; suppress message 302 from list file

	__CONFIG   _CP_OFF & _DATA_CP_OFF & _LVP_OFF & _BOREN_OFF & _MCLRE_ON & _WDT_OFF & _PWRTE_ON & _INTOSC_OSC_NOCLKOUT 

; '__CONFIG' directive is used to embed configuration word within .asm file.
; The lables following the directive are located in the respective .inc file.
; See data sheet for additional information on configuration word settings.
        
	cblock	0x20			;Ram address
	TX				;the 4015
	CountSPI
	count1 			;used in delay routine
	counta 			;used in delay routine 
	countb 			;used in delay routine
	endc 

	#define		Data 	PORTA,0	;hardware
	#define		Clock 	PORTA,1
	#define		Clock0	PORTA,2
	org	0x0000			;reset
	goto	Main			
	org	0x04			;interrupt vector
	goto	Main			;no interrupts
	include "HC4015.inc"	
Main					;main program

	movlw	0x07
	movwf	CMCON			;turn comparators off (make it like a 16F84)
	banksel TRISA
	movlw	b'00011000'		;initializing porta
	movwf	TRISA
	banksel	PORTA
	clrf 	PORTA
Send
	movlw 	b'00000001'			;fill tx buffer
	movwf	TX
	HC4015 TX,CountSPI
	call	Delay
	goto	Send1
Send1
	movlw 	b'00000010'			;fill tx buffer
	movwf	TX
	HC4015 TX,CountSPI
	call	Delay
	goto	Send2
Send2
	movlw 	b'00000100'			;fill tx buffer
	movwf	TX
	HC4015 TX,CountSPI
	call	Delay
	goto	Send3
Send3
	movlw 	b'00001000'			;fill tx buffer
	movwf	TX
	call	Delay
	HC4015 TX,CountSPI
	goto Send4
Send4
	movlw 	b'00010000'			;fill tx buffer
	movwf	TX
	call	Delay
	HC4015 TX,CountSPI
	goto Send5
Send5
	movlw 	b'00010000'			;fill tx buffer
	movwf	TX
	HC4015 TX,CountSPI
	call	Delay
	goto	Send6
Send6
	movlw 	b'00100000'			;fill tx buffer
	movwf	TX
	HC4015 TX,CountSPI
	call	Delay
	goto	Send7
Send7
	movlw 	b'01000000'			;fill tx buffer
	movwf	TX
	call	Delay
	HC4015 TX,CountSPI
	goto Send8
Send8
	movlw 	b'10000000'			;fill tx buffer
	movwf	TX
	call	Delay
	HC4015 TX,CountSPI
	goto Send		
Loop
	goto Loop			;hang out here
Delay	
	movlw	d'250'			;delay 250 ms (4 MHz clock)
	movwf	count1
d1	movlw	0xC7
	movwf	counta
	movlw	0x01
	movwf	countb
Delay_0
	decfsz	counta, f
	goto	$+2
	decfsz	countb, f
	goto	Delay_0

	decfsz	count1	,f
	goto	d1
	retlw	0x00


	END                       	; directive 'end of program'
maybe some 1 can tell me what I'm doing wrong the micro is the same
thanks
 
Last edited:
Not sure what to suggest. Check your 4015 connections (particularly that you have both resets held low and the Q4A linked to DATA B), then try adding a couple more NOPs in your macro to slow the clock down a bit, this may give the 4015 a bit more time to respond.

If that doesn't work I recommend you try my separate clock method.

ahydra
 
Hay Ahydra I can load data 4 bits on side A or 4 bits on B side How would I added it in the micro
Code: 
HC4015 macro Var,Var1
	
	Local 	Loop		;label
	movlw	.8		;eight bits to send
	movwf	Var1		
Loop
	rlf	Var,f		;rotate Var to the left

	btfss 	STATUS,C	;carry = 1 ?
	bcf	Data		;if not set line to 0
	
       btfsc	STATUS,C	;is carry = 0 ?
	bsf	Data		;if not set, set data line to 1
        
	bsf	Clock		; generate 1 clock
	nop
	bcf	Clock
	
	decfsz	Var1,f		;bits been sent ?
	goto	Loop1		;if not repeat
       
Loop1	
	Local 	Loop1		;label
	movlw	.8		;eight bits to send
	movwf	Var1		

	rlf	Var,f		;rotate Var to the left

	btfss 	STATUS,C	;carry = 1 ?
	bcf	Data1		;if not set line to 0
	
       btfsc	STATUS,C	;is carry = 0 ?
	bsf	Data1		;if not set, set data line to 1
        
	bsf	Clock		; generate 1 clock
	nop
	bcf	Clock
	
	decfsz	Var1,f		;bits been sent ?
	goto	Loop		;if not repeat

	
	endm
 
Last edited:
That doesn't work lol. But I now have it shifting in the left side It turns on all 4 of B side and scrolls the A side I need it to scroll all 8 here is my new code
Code: 
	list      p=16f628A           ; list directive to define processor
	#include <p16F628A.inc>       ; processor specific variable definitions
   
	errorlevel  -302              ; suppress message 302 from list file

	__CONFIG   _CP_OFF & _DATA_CP_OFF & _LVP_OFF & _BOREN_OFF & _MCLRE_ON & _WDT_OFF & _PWRTE_ON & _INTOSC_OSC_NOCLKOUT 

; '__CONFIG' directive is used to embed configuration word within .asm file.
; The lables following the directive are located in the respective .inc file.
; See data sheet for additional information on configuration word settings.
        
	cblock	0x20			;Ram address
	TX				;the 4015
	TX0
	CountSPI
	count1 			;used in delay routine
	counta 			;used in delay routine 
	countb 			;used in delay routine
	endc 

	#define		Data 	PORTA,0	;hardware
	#define		Clock 	PORTA,1
	#define		Data0	PORTA,2
	org	0x0000			;reset
	goto	Main			
	org	0x04			;interrupt vector
	goto	Main			;no interrupts
	include "HC4015.inc"
	include "SHC4015.inc"
Main					;main program

	movlw	0x07
	movwf	CMCON			;turn comparators off (make it like a 16F84)
	banksel TRISA
	movlw	b'00011000'		;initializing porta
	movwf	TRISA
	banksel	PORTA
	clrf 	PORTA
Send
	movlw 	b'00000001'			;fill tx buffer
	movwf	TX
	HC4015 TX,CountSPI
	call	Delay
	goto	Send1
Send1
	movlw 	b'00000010'			;fill tx buffer
	movwf	TX
	HC4015 TX,CountSPI
	call	Delay
	goto	Send2
Send2
	movlw 	b'00000100'			;fill tx buffer
	movwf	TX
	HC4015 TX,CountSPI
	call	Delay
	goto	Send3
Send3
	movlw 	b'00001000'			;fill tx buffer
	movwf	TX
	call	Delay
	HC4015 TX,CountSPI
	goto Send4
Send4
	movlw 	b'00001000'			;fill tx buffer
	movwf	TX
	call	Delay
	HC4015 TX,CountSPI
	goto Send5
Send5
	movlw 	b'00000001'			;fill tx buffer
	movwf	TX0
	call	Delay
	SHC4015 TX0,CountSPI
	goto Send			
Loop
	goto Loop			;hang out here
Delay	
	movlw	d'250'			;delay 250 ms (4 MHz clock)
	movwf	count1
d1	movlw	0xC7
	movwf	counta
	movlw	0x01
	movwf	countb
Delay_0
	decfsz	counta, f
	goto	$+2
	decfsz	countb, f
	goto	Delay_0

	decfsz	count1	,f
	goto	d1
	retlw	0x00


	END                       	; directive 'end of program'
and the macro I added I'm using both macro
Code: 
SHC4015 macro Var,Var2
	
	Local 	Loop		;label
	movlw	.8		;eight bits to send
	movwf	Var2		
Loop
	rlf	Var,f		;rotate Var to the left

	btfss 	STATUS,C	;carry = 1 ?
	bcf	Data0		;if not set line to 0
	btfsc	STATUS,C	;is carry = 0 ?
	bsf	Data0		;if not set, set data line to 1

;	bsf	Clock		; generate 1 clock
;	nop
;	nop
;	nop
;	bcf	Clock
	
	decfsz	Var2,f		;bits been sent ?
	goto	Loop		;if not repeat

	endm
Thanks 4 any help
Burt
 
Here is what I'm working on
 

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Well I found why it wasn't sending the clock to the shift register It wasn't going to the Loop Maybe tomorrow I'll get it right thanks for all help
 
Last edited:
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