Post by thread:509 flasher

I have tried this program and it will not work! (shown below) Pins 6 and 7 are doing something, but they only switch between 0 and around 1.7 volts! It is wired up like this: Pin 1 +5V Pin 2 NC Pin 3 NC Pin 4 NC Pin 5 NC Pin 6 ---------/\/\/\/\/\---------|>|---------Gnd 330 ohm Pin 7 as pin 5 Pin 8 Gnd Have you any ideas? Graham LIST P=12C509 RADIX DEC INCLUDE <P12C509.INC> CBLOCK 0X0007 LOOP1 ENDC __CONFIG _CP_OFF & _MCLRE_OFF & _WDT_OFF & _IntRC_OSC ORG 0X3FF MOVLW 0X80 ORG 0X0000 MOVWF OSCCAL GOTO START DLY100 MOVLW 100 DLYMS MOVWF LOOP1 DY0 MOVLW -125 MOVWF TMR0 DY1 MOVF TMR0,W IORLW 0 BTFSS STATUS,Z GOTO DY1 DECFSZ LOOP1,F GOTO DY0 RETLW 0 DIT BSF GPIO,0 BSF GPIO,1 CALL DLY100 BCF GPIO,0 BCF GPIO,1 CALL DLY100 CALL DLY100 RETLW 0 DAH BSF GPIO,0 BSF GPIO,1 CALL DLY100 CALL DLY100 CALL DLY100 BCF GPIO,0 BCF GPIO,1 CALL DLY100 CALL DLY100 RETLW 0 SENDSPACE CALL DLY100 CALL DLY100 CALL DLY100 CALL DLY100 RETLW 0 ORG 0X0100 START MOVLW B'11000010' MOVLW 0 MOVWF GPIO MOVLW 0 TRIS GPIO OPTION LOOP ; ;T CALL DAH CALL SENDSPACE ;H CALL DIT CALL DIT CALL DIT CALL DIT CALL SENDSPACE ;I CALL DIT CALL DIT CALL SENDSPACE ;S CALL DIT CALL DIT CALL DIT CALL SENDSPACE ;SPACE CALL SENDSPACE CALL SENDSPACE ;I CALL DIT CALL DIT CALL SENDSPACE ;S CALL DIT CALL DIT CALL DIT CALL SENDSPACE ;SPACE CALL SENDSPACE CALL SENDSPACE ;A CALL DIT CALL DAH CALL SENDSPACE ;SPACE CALL SENDSPACE CALL SENDSPACE ;T CALL DAH CALL SENDSPACE ;E CALL DIT CALL SENDSPACE ;S CALL DIT CALL DIT CALL DIT CALL SENDSPACE ;T CALL DAH CALL SENDSPACE CALL SENDSPACE CALL SENDSPACE GOTO LOOP END

> __CONFIG _CP_OFF & _MCLRE_OFF & _WDT_OFF & _IntRC_OSC Aren't you supposed to combine configuration flags with '|' or '+', not '&'? ANDing together a series of bit flags is guaranteed to give you a zero - I'm not sure exactly what effect a zero has as the configuration word, but I suspect it's setting the PIC for an external clock or something else incompatible with how you've wired your circuit. > START MOVLW B'11000010' > MOVLW 0 > MOVWF GPIO > MOVLW 0 > TRIS GPIO > OPTION That first MOVLW is accomplishing nothing, since you immediately overwrite W with a zero. I suspect that the value 11000010 was intended to go into the OPTION register, but you inserted some other code in between. The main effect of your storing 0 in OPTION instead is to set the Timer0 prescaler to 1:2 instead of 1:8. This would make your LED blink 4 times as fast as it should, but wouldn't explain why it doesn't work at all - I'm pretty sure that the config word is your real problem. Jason Harper

part 0 8208 bytes Aren't you supposed to combine configuration flags with '|' or '+', not '&'?  ANDing together a series of bit flags is guaranteed to give you a zero - I'm not sure exactly what effect a zero has as the configuration word, but I suspect it's setting the PIC for an external clock or something else incompatible with how you've wired your circuit. >         START  MOVLW   B'11000010' >                MOVLW   0 >                MOVWF   GPIO >                MOVLW   0 >                TRIS    GPIO >                OPTION That first MOVLW is accomplishing nothing, since you immediately overwrite W with a zero.  I suspect that the value 11000010 was intended to go into the OPTION register, but you inserted some other code in between.  The main effect of your storing 0 in OPTION instead is to set the Timer0 prescaler to 1:2 instead of 1:8.  This would make your LED blink 4 times as fast as it should, but wouldn't explain why it doesn't work at all - I'm pretty sure that the config word is your real problem.         Jason Harper </UL> I did notice that the program is full of instances of consecutive bit operations on the GPIO port, never a good thing to do. Also I think the delay routine may be a bit dodgy.  The coments are mine, but I'm trying to illustrate the fact that to work properly, the timer would have to roll over to zero exactly as the MOVF TMR0,W instruction is being executed.  It's hardly worth using the timer for delays like this.  As you are using 100% cpu time polling the timer, you might just as well use a pure software delay. DLY100          MOVLW   100             ; do 100 timer loops DLYMS   MOVWF   LOOP1   DY0             MOVLW   -125            ; pre-load TMR0 with -125                         MOVWF   TMR0 DY1             MOVF   TMR0,W   ; grab TMR0 register (timer must be zero here to work properly)                         IORLW   0                       ; is it zero?  (might roll over to zero here)                         BTFSS   STATUS,Z                    (or here)                         GOTO    DY1             ; no check again (or here)                         DECFSZ  LOOP1,F ; yes, decrement outer loop                         GOTO    DY0 The fact that the voltage on the ports is rising to 1.7 volts suggests that the pin is configured as an input and is floating.  This ties in with the incorrect CONFIG.  The ports default to input on power up, and if the PIC isn't running it'll never get configured as an output. Mike </BODY> </HTML> </x-html>

Hi Graham, This code definitely works on my 12C509. Plonk it into MPASM (or whatever) and compile it. Then program your chip. A LED connected to GPIO 1 (pin6) through a 330R resistor to ground should flash at about a 1/2 second rate when you connect power. If yours does not work there will be other problems. Verify your chip after programming and make sure your circuit connections are correct. If it does work, try integrating some of your code into this, a little at a time, until you get it all going. The prescaler setting has been changed to allow the code to detect when TMR0 = 0. To get a faster flash rate change the value of "LOOP1". LIST P=12C509 RADIX DEC INCLUDE <P12C509.INC> CBLOCK 0X07 LOOP1 ENDC __CONFIG _CP_OFF & _MCLRE_OFF & _WDT_OFF & _IntRC_OSC ORG 0X3FF MOVLW 0X80 ORG 0X0000 MOVWF OSCCAL GOTO START DELAY MOVF TMR0,w ; TMR0 must be zero for these instructions if the loop is to work BTFSS STATUS,Z ; TMR0 must be zero for these instructions if the loop is to work GOTO DELAY ; TMR0 must be zero for these instructions if the loop is to work DECFSZ LOOP1 GOTO DELAY RETLW 0 START MOVLW 0 ; set al pins = 0 MOVWF GPIO MOVLW 0 ; set all pins as outputs TRIS GPIO MOVLW B'11010010' ; TMR0 internal clock, PRESCALER 1:4 OPTION FLASH MOVLW B'00000010' XORWF GPIO CLRF LOOP1 ; LOOP1 value determines delay. 0 = MAXIMUM CALL DELAY GOTO FLASH END -- Best regards Tony http://www.picnpoke.com salesKILLspampicnpoke.com