8051 I/O problem :S

thedarkshade · November 13, 2011

Hey everyone.

I've been working for quite a while on this one. I've been trying to make a VT100 terminal emulator through serial port (RS232 standard) using Easy8051A development board. I've written down the entire code for writing from hyperterminial (yeah, I nedded XP for that) to a 2x16 LCD (8-bit mode) and also for writing from the board to hyperterminal, but I got stuck trying to bring the two together. I know I must somehow use serial interrupts to check whether a key has been pressed or not but I can't just quite figure it out.

I'll post the code down here, just in case anyone has any bit of idea of how could I proceed.

This is the code to write to the LCD (control codes including):

ESC EQU 1BH

ORG 0000H

LJMP MAIN

ORG 0023H

MAIN:
BUSY BIT P0.7
E BIT P2.4
RS BIT P2.2
RW BIT P2.3

MOV A, PCON
SETB ACC.7
MOV PCON, A
MOV SCON, #52h
MOV TMOD, #20h
MOV TH1, #-35
SETB EA
SETB ES
SETB PS
SETB TR1
CALL LCD_INIT;

PRANO: 
JNB RI, $  ; KONTROLLO A ESHTE SHRYPUR NDOJE KARAKTER
CLR RI
MOV A, SBUF
CHECK_DEL:
CJNE A, #7FH, CONTINUE
LJMP CLEAR_LCD
LJMP NEXT


CONTINUE:
CJNE A, #ESC, NO_ESC1
CLR P1.7
JNB RI, $
CLR RI
MOV A, SBUF
CJNE A, #'[', NO_KLLAPA
JNB RI, $
CLR RI
MOV A, SBUF
CJNE A, #'C', CHECK_D
LCALL MOVE_LEFT
LJMP NEXT

CHECK_D:
CJNE A, #'D', CHECK_A
LCALL MOVE_RIGHT
LJMP NEXT

CHECK_A:
CJNE A, #'A', CHECK_B
LCALL MOVE_UP
LJMP NEXT

CHECK_B:
CJNE A, #'B', NEXT
LCALL MOVE_DOWN
LJMP NEXT	




NO_ESC1:	LJMP NO_ESC

MOVE_LEFT:	
	MOV A, #14H
	ACALL COMMAND
	RET

MOVE_RIGHT:
	MOV A, #10H
	ACALL COMMAND
	RET

MOVE_UP:
	LCALL READY
	MOV A, P0
	ANL A,#00111111B
	MOV R7, A
	MOV A, #40H
	SUBB A, R6
	MOV R6, A
	MOV A, R7
	SETB ACC.7
	ACALL COMMAND
	RET

MOVE_DOWN:
	LCALL READY
	MOV A, P0
	ANL A, #00111111B
	MOV R6, A
	MOV A, #40H
	ADD A, R6
	MOV R7, A
	MOV A, R7
	SETB ACC.7
	ACALL COMMAND
	RET	

CLEAR_LCD:
	MOV A, #01H
	CALL COMMAND		




NO_KLLAPA:
LJMP NEXT

;******************************************************************
LCD_INIT:			 				 ;*
MOV A, #38H	; 2 Linja 5x7	 			 ;*
ACALL COMMAND		 				 ;*
MOV A, #0DH	;Aktivizimi i Kursorit (Blinkues)	 ;*
ACALL COMMAND		 				 ;*
MOV A, #01H	;Fshirja e ekranit	 	       	 ;*
ACALL COMMAND		 				 ;*
MOV A, #06H	;Vendosja e Kursorit Ne Te Djathe	 ;*
ACALL COMMAND						 ;*
RET			 				 ;*
							 ;*		   \
			 				 ;*=================\
COMMAND: 			 				 ;*==================\
ACALL READY		 				 ;*==================/   Pergaditja e LCD-se        
MOV P0, A		 				 ;*=================/
CLR RS							 ;*		   /
CLR RW			 				 ;*
SETB E			 				 ;*
CLR E			 				 ;*
RET			 				 ;*
			 				 ;*
			 				 ;*
			 				 ;*
READY:				 				 ;*
SETB BUSY		 				 ;*
MOV P0, #0FFH		 				 ;*
CLR RS			 				 ;*
SETB RW			 				 ;*
BACK:				 				 ;*
CLR E			 				 ;*
SETB E			 				 ;*
JB BUSY, BACK		 				 ;*
RET			 				 ;*
			 				 ;*
;******************************************************************	

NO_ESC:
LCALL LCD_DISPLAY
CPL A
MOV P1,A
NEXT:
SETB P1.7
LJMP PRANO


LCD_DISPLAY:
ACALL READY
CLR E
MOV P0, A
SETB RS
CLR RW
SETB E
CLR E
RET


STOP:

END

This is the code for hyperterminal-to-board:

ORG 0000H

MOV A, PCON	;|
SETB ACC.7	;|------->Mundesimi i Dyfishimit te Baud-Rate (SMOD=1)
MOV PCON, A	;|
;----------------|      

MOV SCON, #52H	;Pori Serik, Modi 1	
MOV TMOD, #20H	;Timeri-i 1, Modi 2
MOV TH1, #-35	; 1200 baud-rate
SETB TR1	; Starton timer-in 1


WRITE_TO_TERMINAL:
JB P0.0, CHECK_B

WRITE_A:
MOV A, #41H
CALL OUTCHR

CHECK_B:JB P0.1, CHECK_C

WRITE_B:
MOV A, #42H
CALL OUTCHR

CHECK_C:JB P0.2, CHECK_D

WRITE_C:
MOV A, #43H
CALL OUTCHR

CHECK_D:JB P0.3, CHECK_E

WRITE_D:
MOV A, #44H
CALL OUTCHR


CHECK_E: JB P0.4, CHECK_F

WRITE_E:
MOV A, #45H
CALL OUTCHR

CHECK_F:JB P0.5, CHECK_G

WRITE_F:
MOV A, #46H
CALL OUTCHR

CHECK_G:JB P0.6, CHECK_H

WRITE_G:
MOV A, #47H
CALL OUTCHR	

CHECK_H:JB P0.7, CHECK_I

WRITE_H:
MOV A, #48H
CALL OUTCHR

CHECK_I:JB P1.0, CHECK_J
WRITE_I:
MOV A, #49H
CALL OUTCHR

CHECK_J: JB P1.1, CHECK_K
WRITE_J:
MOV A, #04AH
CALL OUTCHR

CHECK_K: JB P1.2, CHECK_L
WRITE_K:
MOV A, #04BH
CALL OUTCHR

CHECK_L: JB P1.3, CHECK_M
WRITE_L:
MOV A, #04CH
CALL OUTCHR

CHECK_M: JB P1.4, CHECK_N
WRITE_M:
MOV A, #04DH
CALL OUTCHR

CHECK_N: JB P1.5, CHECK_O
WRITE_N:
MOV A, #04EH
CALL OUTCHR

CHECK_O: JB P1.6, CHECK_P
WRITE_O:
MOV A, #04FH
CALL OUTCHR

CHECK_P: JB P1.7, CHECK_Q
WRITE_P:
MOV A, #50H
CALL OUTCHR

CHECK_Q: JB P2.0, CHECK_R
WRITE_Q:
MOV A, #51H
CALL OUTCHR

CHECK_R: JB P2.1, CHECK_S
WRITE_R:
MOV A, #52H
CALL OUTCHR

CHECK_S: JB P2.2, CHECK_T
WRITE_S:
MOV A, #53H
CALL OUTCHR

CHECK_T: JB P2.3, CHECK_U
WRITE_T:
MOV A, #54H
CALL OUTCHR

CHECK_U: JB P2.4, CHECK_V
WRITE_U:
MOV A, #55H
CALL OUTCHR

CHECK_V: JB P2.5, CHECK_W
WRITE_V:
MOV A, #56H
CALL OUTCHR

CHECK_W: JB P2.6, CHECK_X
WRITE_W:
MOV A, #57H
CALL OUTCHR

CHECK_X: JB P2.7, CHECK_Y
WRITE_X:
MOV A, #58H
CALL OUTCHR

CHECK_Y: JB P3.2, CHECK_Z
WRITE_Y:
MOV A, #59H
CALL OUTCHR

CHECK_Z: JB P3.3, CHECK_SPACE
WRITE_Z:
MOV A, #05AH
CALL OUTCHR

CHECK_SPACE: JB P3.4, CHECK_AGAIN
WRITE_SPACE:
MOV A, #' '
CALL OUTCHR

CHECK_AGAIN: LCALL WRITE_TO_TERMINAL


OUTCHR:	JNB TI, OUTCHR
CLR TI
CALL VONESA
MOV SBUF, A

CALL WRITE_TO_TERMINAL

VONESA:	MOV R6, #0FFH
MOV R7, #05FH
PERS:		MOV R5, #0FFH
	DJNZ R5, $
	DJNZ R7, $
	DJNZ R6, PERS

	RET


STOP:
END

and this is how I've tried to bring the two together (unsuccessfully):

ESC EQU 1BH

ORG 0000H

LJMP MAIN

ORG 0023H
LJMP ISR

ORG 0030H


MAIN:
BUSY BIT P0.7
E BIT P2.4
RS BIT P2.2
RW BIT P2.3

MOV A, PCON
SETB ACC.7
MOV PCON, A
MOV SCON, #52h
MOV TMOD, #20h
MOV TH1, #-35
SETB EA
SETB ES
SETB PS
SETB TR1
CALL LCD_INIT;

PRANO: 
JNB RI, $  ; KONTROLLO A ESHTE SHRYPUR NDOJE KARAKTER
CLR RI
JNB P1.0, GO_INT_I
JNB P1.1, GO_INT_J
JNB P1.2, GO_INT_K
JNB P1.3, GO_INT_L
JNB P1.4, GO_INT_M
JNB P1.5, GO_INT_N
JNB P1.6, GO_INT_O
JNB P1.7, GO_INT_P
MOV A, SBUF
JMP CHECK_DEL
GO_INT_I: 
CLR P1.0
MOV IE, #90H
JMP PRANO

GO_INT_J: 
CLR P1.1
MOV IE, #90H
JMP PRANO

GO_INT_K: 
CLR P1.2
MOV IE, #90H
JMP PRANO

GO_INT_L: 
CLR P1.3
MOV IE, #90H
JMP PRANO

GO_INT_M: 
CLR P1.4
MOV IE, #90H
JMP PRANO

GO_INT_N: 
CLR P1.5
MOV IE, #90H
JMP PRANO

GO_INT_O: 
CLR P1.6
MOV IE, #90H
JMP PRANO

GO_INT_P: 
CLR P1.7
MOV IE, #90H
JMP PRANO

CHECK_DEL:
CJNE A, #7FH, CONTINUE
LJMP CLEAR_LCD
LJMP NEXT


CONTINUE:
CJNE A, #ESC, NO_ESC1
CLR P1.7
JNB RI, $
CLR RI
MOV A, SBUF
CJNE A, #'[', NO_KLLAPA
JNB RI, $
CLR RI
MOV A, SBUF
CJNE A, #'C', CHECK_D
LCALL MOVE_LEFT
LJMP NEXT

CHECK_D:
CJNE A, #'D', CHECK_A
LCALL MOVE_RIGHT
LJMP NEXT

CHECK_A:
CJNE A, #'A', CHECK_B
LCALL MOVE_UP
LJMP NEXT

CHECK_B:
CJNE A, #'B', NEXT
LCALL MOVE_DOWN
LJMP NEXT	




NO_ESC1:	LJMP NO_ESC

MOVE_LEFT:	
	MOV A, #14H
	ACALL COMMAND
	RET

MOVE_RIGHT:
	MOV A, #10H
	ACALL COMMAND
	RET

MOVE_UP:
	LCALL READY
	MOV A, P0
	ANL A,#00111111B
	MOV R7, A
	MOV A, #40H
	SUBB A, R6
	MOV R6, A
	MOV A, R7
	SETB ACC.7
	ACALL COMMAND
	RET

MOVE_DOWN:
	LCALL READY
	MOV A, P0
	ANL A, #00111111B
	MOV R6, A
	MOV A, #40H
	ADD A, R6
	MOV R7, A
	MOV A, R7
	SETB ACC.7
	ACALL COMMAND
	RET	

CLEAR_LCD:
	MOV A, #01H
	CALL COMMAND		




NO_KLLAPA:
LJMP NEXT

;******************************************************************
LCD_INIT:			 				 ;*
MOV A, #38H	; 2 Linja 5x7	 			 ;*
ACALL COMMAND		 				 ;*
MOV A, #0DH	;Aktivizimi i Kursorit (Blinkues)	 ;*
ACALL COMMAND		 				 ;*
MOV A, #01H	;Fshirja e ekranit	 	       	 ;*
ACALL COMMAND		 				 ;*
MOV A, #06H	;Vendosja e Kursorit Ne Te Djathe	 ;*
ACALL COMMAND						 ;*
RET			 				 ;*
							 ;*		   \
			 				 ;*=================\
COMMAND: 			 				 ;*==================\
ACALL READY		 				 ;*==================/   Pergaditja e LCD-se        
MOV P0, A		 				 ;*=================/
CLR RS							 ;*		   /
CLR RW			 				 ;*
SETB E			 				 ;*
CLR E			 				 ;*
RET			 				 ;*
			 				 ;*
			 				 ;*
			 				 ;*
READY:				 				 ;*
SETB BUSY		 				 ;*
MOV P0, #0FFH		 				 ;*
CLR RS			 				 ;*
SETB RW			 				 ;*
BACK:				 				 ;*
CLR E			 				 ;*
SETB E			 				 ;*
JB BUSY, BACK		 				 ;*
RET			 				 ;*
			 				 ;*
;******************************************************************	

NO_ESC:
LCALL LCD_DISPLAY
CPL A
MOV P1,A
NEXT:
MOV P1, #0FFH
LJMP PRANO


LCD_DISPLAY:
ACALL READY
CLR E
MOV P0, A
SETB RS
CLR RW
SETB E
CLR E
RET


ISR:
WRITE_TO_TERMINAL:


CHECK_I:JB P1.0, CHECK_J
WRITE_I:
MOV A, #49H
CALL OUTCHR

CHECK_J: JB P1.1, CHECK_K
WRITE_J:
MOV A, #04AH
CALL OUTCHR

CHECK_K: JB P1.2, CHECK_L
WRITE_K:
MOV A, #04BH
CALL OUTCHR

CHECK_L: JB P1.3, CHECK_M
WRITE_L:
MOV A, #04CH
CALL OUTCHR

CHECK_M: JB P1.4, CHECK_N
WRITE_M:
MOV A, #04DH
CALL OUTCHR

CHECK_N: JB P1.5, CHECK_O
WRITE_N:
MOV A, #04EH
CALL OUTCHR

CHECK_O: JB P1.6, CHECK_P
WRITE_O:
MOV A, #04FH
CALL OUTCHR

CHECK_P: JB P1.7, CHECK_AGAIN
WRITE_P:
MOV A, #50H
CALL CHECK_AGAIN



CHECK_AGAIN: RETI


OUTCHR:	JNB TI, OUTCHR
CLR TI
CALL VONESA
MOV SBUF, A
CLR EA
RETI

VONESA:	MOV R6, #0FFH
MOV R7, #05FH
PERS:		MOV R5, #0FFH
	DJNZ R5, $
	DJNZ R7, $
	DJNZ R6, PERS

	RET

END

I know it's exceedingly boring to go through it all (neither I expext you to) but I'd really appreciate every idea on how to bring the two together.

Regards,

TDS

Edited November 13, 2011 by thedarkshade

moth · November 14, 2011

Is your keyboard connected to the 8051 or your PC?

If you could add some comments to your code it will make it a little easier to sort out.

thedarkshade · November 14, 2011

No no, I'm using pushbuttons on the board as keys.

I got it to work lasht night actually. I seem to have been carrying a bit from the ISR routine that was causing me trouble.

P.s. I apologize for lack of comments (not a good programmer). Some of the labels too are in my native language

thedarkshade · November 14, 2011

Oh, and btw is there something like "8051 LCD command list" like the 'enter command' or 'backspace'?

The ones I have above (move_left, move_right, del,...) I collected from several books I happen to have on microcontrollers, but I feel my project's lacking a taste of completeness.

moth · November 15, 2011

No no, I'm using pushbuttons on the board as keys.

O.K. I was wondering why there's no translation from keyboard scan codes to ascii.

You've probably seen the sample code from this page already, but just in case here's a link.

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8051 I/O problem :S

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