Post by thread:Coding Problem

Hi there (it's me again) I've got another problem, I have written some code that scans 0-7 bits of PORT B and checks to see if 0-7 bits are back low again. (Code) ;Routine to handle a 4 digit code (password) using the 16F84 ;Pass.asm using TASM.EXE -1684 -B ;Setup global variables STATUS: .EQU $03 PORTA: .EQU $05 PORTB: .EQU $06 Z: .EQU 2 W: .EQU 0 C: .EQU 0 IN: .EQU 0 ;Stores current digit code .ORG 4 .ORG 5 ;Clear Ports A and B clrf PORTA clrf PORTB bsf STATUS,5 ;Page 1 movlw %00000 ;Port A, all output movwf PORTA movlw %11111111 ;Port B, all output movwf PORTB bcf STATUS,5 ;Page 0 ;Reset ports a and b clrf PORTA clrf PORTB INIT: bsf PORTA,0 ;Indicate to user that power is on Call KeyScan ;Check to see if the user can movlw IN ;(test only) This is the value of the digit entered movwf PORTB ;(test only) Displays the digit to PORTB Goto INIT ;Re-start KeyScan: movlw %00000000 ;Check to see if the user has entered a digit xorwf PORTA,W btfsc STATUS,Z Goto KeyScan ;No, recheck movlw PORTB ;Store the value movwf IN ;(IN) KeyCheck: bcf STATUS,Z ;Check to see key has been released clrf PORTA movlw %00000000 xorwf PORTA,W btfsc STATUS,Z return ;Yes, key has been released Goto KeyCheck ;No, still waiting for release, recheck .END The problem here is that I want to store the value in PORT B into variable 'IN' and display the value to PORT A, for testing purpose. This doe not work, any comments would be greatefull. Pul Phillips spam_OUTPICTakeThisOuTColindale.demon.co.uk

Paul Phillips wrote: > > Hi there (it's me again) > > I've got another problem, I have written some code that scans 0-7 bits Just as a quick look, you have defined 'IN' as the INDF register, so your data will goto the register pointed to by the FSR, which could be anywhere as it has not been initialised. Try IN equ 0ch or similar. You should be scanning portb for a keypress, not porta. When reading portb, movlw PORTB will not work. Try movf PORTB,w. -- Best regards Tony Multimedia 16F84 Beginners PIC Tools. http://www.picnpoke.com Email .....picnpokeKILLspam@spam@cdi.com.au

Hi, Please find below my comments. Paul Phillips wrote: {Quote hidden}> > Hi there (it's me again) > > I've got another problem, I have written some code that scans 0-7 bits of > PORT B and checks to see if 0-7 bits are back low again. > > (Code) > ;Routine to handle a 4 digit code (password) using the 16F84 > ;Pass.asm using TASM.EXE -1684 -B > ;Setup global variables > STATUS: .EQU $03 > PORTA: .EQU $05 > PORTB: .EQU $06 > Z: .EQU 2 > W: .EQU 0 > C: .EQU 0 > IN: .EQU 0 ;Stores current digit code Register IN should be mapped to a general purpose register not INDF. Change this to: IN EQU 0x0C > .ORG 4 > .ORG 5 Program memory location 0 is the reset vector. While Location 4 is the interrupt vector Should be: ORG 0 goto start ORG 4 start: > ;Clear Ports A and B > clrf PORTA > clrf PORTB > bsf STATUS,5 ;Page 1 > movlw %00000 ;Port A, all output > movwf PORTA > movlw %11111111 ;Port B, all output ????? > movwf PORTB You had set PORTB as input while PORTA as OUTPUT . But below you reversed your ports. > bcf STATUS,5 ;Page 0 > ;Reset ports a and b > clrf PORTA > clrf PORTB > INIT: > bsf PORTA,0 ;Indicate to user that power is on > Call KeyScan ;Check to see if the user can > movlw IN ;(test only) This is the value of the digit entered You confused movlw with movf. This line should be: movf IN,W > movwf PORTB ;(test only) Displays the digit to PORTB > Goto INIT ;Re-start > KeyScan: > movlw %00000000 ;Check to see if the user has entered a digit > xorwf PORTA,W > btfsc STATUS,Z Here is the PROBLEM. You checked PORTA instead of PORTB. PORTA is the output. It should be xorwf PORTB,W. One way to check if any input is held high is: movf PORTB,W btfsc STATUS,Z > Goto KeyScan ;No, recheck > movlw PORTB ;Store the value MOVLW instead of MOVF. This should be: movf PORTB,W > movwf IN ;(IN) > KeyCheck: > bcf STATUS,Z ;Check to see key has been released > clrf PORTA > movlw %00000000 > xorwf PORTA,W Here also PORTA instead of PORTB. > btfsc STATUS,Z > return ;Yes, key has been released > Goto KeyCheck ;No, still waiting for release, recheck > .END > > The problem here is that I want to store the value in PORT B into variable > 'IN' and display the value to PORT A, for testing purpose. This doe not > work, any comments would be greatefull. regards, Reggie

part 0 651 bytes content-type:application/octet-stream;I've started using MPLAB (V4.0), currently i'm trying to write some code to allow a user to enter a 5 digit number (code). When trying this using MPLAB, it seems to work ok, but when I download the code to the PIC, does not perform correct. When the user enters the first digit, then increase the count. The problem here, it never reaches the count rountine. Any comments Cheers Paul Phillips PICKILLspamColindale.demon.co.uk Content-Type: application/octet-stream; name="password.asm" Content-Disposition: attachment; filename="password.asm" Attachment converted: wonderland:password.asm (????/----) (00020D9C)

Paul Phillips wrote: > I've started using MPLAB (V4.0), currently i'm trying to write some code to > allow a user to enter a 5 digit number (code). When trying this using > MPLAB, it seems to work ok, but when I download the code to the PIC, does > not perform correct. > > When the user enters the first digit, then increase the count. The problem > here, it never reaches the count rountine. The problem you may have is debouncing. You did not include a routine to debounce your keys. Also, KeyCount routine will stop incrementing COUNT reaches 0xFF. KeyCount: bsf PORTA,3 ;Increase the key count incfsz COUNT,W ;change the 2 lines to: movwf COUNT ; incf COUNT,f ;first digit movf COUNT,W xorlw b'00000001' btfsc STATUS,Z bsf PORTA,3 ;fifth digit movf COUNT,W xorlw b'00000101' btfsc STATUS,Z bcf PORTA,3 return regards, Reggie

Cheers for the input Wouter, I have tried the basic things I can think of. I'm using a PIC TUTOR board, which I can write code using a text editor which is compiled into hex via tasm.exe, I then used a program called 'Send.exe' to send the program to the PIC (via the PIC Tutor). I have started use use the MPLAB (v4.0), where I have written some test code (flasing an LED), compiled it to a hex file, used the 'Send.Exe' program to send it to the PIC. Can not get the thing to work at all, event the example code that comes with MPLAB does not work! Cheers Paul Phillips EraseMEPICspam_OUTTakeThisOuTColindale.demon.co.uk

Hi there i'm using MPLAB (v4.0) and PIC Tutor Programmer/simulator. I can get MPLAB to simulate my coding, I compile the code to HEX without any errors. I can send the HEX to the PIC16F84 ok, but the PIC does not do anything, is this a coding problem or MPLAB problem/setup. Cheers Picspam_OUTColindale.demon.co.uk '________________________________________ ;Project Name : Password.pjt ;Asm File : Password.asm ;Date : 10/12/1998 ;Version : 1.0 ;Purpose : To handle a 5 digit code via 7 line keypad ;Set-up ;_______________________________________________________________ ;PORTA ;0 = OUT : Power ON ;1 = OUT : Key Pressed ;2 = OUT : First Digit Entered ;3 = OUT : 5th digit entered ;4 = OUT : <NOT USED> ;PORTB ;0 - 6 = IN : Input from keypad ;7 = Accept : Accept Code #define page1 bsf status,5 ;Page 1 #define page0 bcf status,5 ;Page 0 status equ 0x03 ;Status porta equ 0x05 ;Link to port a portb equ 0x06 ;Link to port b w equ 0 ;Working file f equ 1 ;File z equ 2 stable equ 0x08 ;Used for delay factor for debouncing inputs in equ 0x09 ;Stores the port b digit keywait equ 0x0A ;Counter for debouncing routine digno equ 0x0B ;Digit number entered (upto five) dig1 equ 0x0C ;Store digit 1 dig2 equ 0x0D ;Store digit 2 dig3 equ 0x0E ;Store digit 3 dig4 equ 0x0F ;Store digit 4 list p=16F84 #include p16f84.inc org 4 org 5 ;defaults clrf porta clrf portb page1 ;Page 1 ;set porta movlw b'00000' movwf porta ;port b movlw b'1111111' movwf portb page0 ;Reset variables clrf keywait clrf stable clrf in clrf digno clrf dig1 clrf dig2 clrf dig3 clrf dig4 ;Indicate to the outside world the the pic is running (port a,0) bsf porta,0 begin: call KeyScan ;Get input from port b ;inform the outside world that the user has realeased (port a,1) bcf porta,1 ;User has pressed a button (stored in 'in) ;Get the next digit number call getnextdigit goto begin KeyScan: ;Check to see if the any of the bits are high movlw b'00000000' xorwf portb,W btfsc status,z Goto KeyScan ;No, recheck clrf keywait movf portb,w ;Store the value of port b movwf in ;inform the outsite that a keypress event has occurred (port a,1) bsf porta,1 debounce: ;wait x times to stable input ;increase the keywait by 1 incfsz keywait,f ;is keywait=stable movf keywait,w xorlw b'00001000' btfss status,z goto debounce ;no KeyCheck: ;Wait to see if all bits are low bcf status,z ;Clear status and PORTB movlw b'00000000' xorwf portb,w btfsc status,z return ;Yes, all bits are low Goto KeyCheck ;no, wait until all bits are low goto begin getnextdigit: ;increase the digit count no by one incfsz digno,f ;check for first digit movf digno,w xorlw d'1' btfsc status,z call dig_1 return dig_1: ;inform other obhjects that the first digit has been entered bsf porta,2 ;store the value in dig1 movf in,w movwf dig1 return end