Post by thread:prevent unwanted reset (used to be "Help me please

Hello, [RE: "help me please!!" messages] To refresh memmory I am running the following code: ------------- Main MOVLW h'06' ; turn on an LED and a motor (h-bridge) MOVWF PORTB NOP WaitHere CALL Delay2 ; simply delay a little (it runs ok!) BTFSC PORTA,1 ; if pin 1 of porta goes high... turn everything off GOTO Finish GOTO WaitHere Finish CLRF PORTB ; NEVER PASSES THIS STAGE SINCE IT IS RESETING! dodod ; loop doing nothing NOP CALL Delay2 GOTO dodod END -------- Well, what is happening is that the motor and an LED are turned and remain on as long as the pin 1 on porta remains low. That is all good. The problems happen when I turn the pin 1 on porta to high, the motor and the LED seem to stop. BUT then a reset happens to the chip and hence it oscillates, and never stopping. NOTE: motor is controlled by H-bridge (74F139) I don't want the chip to restart when the motor is turned on! I am propably doing something wrong! At the momment I have MCLR of the PIC through a 1K resistor to high, and an 0.1 capacitor to a low. The Vdd is connected to a high. Vss is connected to a low. Across my 5V regulator I have a 1000uF capacitor. Across the Vdd and Vss I have connected a 0.1uF cap. NOTE: the motors only require 2V, >30mA to run. I have checked all of the voltages on both the chips and they are both at 5V. Can someone help me in setting the circuit up such that PIC does not reset! I need to get this running by tonight, and I am having no luck. I will continue to test and if I get any progress I will let the list know, but so far I have been having no reset. I thank everyone for the help. ------------- Sep. S. spam_OUTmeTakeThisOuTsep.2y.net -----------

<x-flowed>I would suggest turning off the watchdog timer or clearing it from time to time. John C. At 03:34 PM 01/16/1980 -0400, you wrote: {Quote hidden}>Hello, >[RE: "help me please!!" messages] > > >To refresh memmory I am running the following code: >------------- >Main > MOVLW h'06' ; turn on an LED and a motor (h-bridge) > MOVWF PORTB > NOP > >WaitHere > CALL Delay2 ; simply delay a little (it runs ok!) > BTFSC PORTA,1 ; if pin 1 of porta goes high... turn > everything off > GOTO Finish > GOTO WaitHere > >Finish > CLRF PORTB ; NEVER PASSES THIS STAGE SINCE > IT IS RESETING! > >dodod ; loop doing nothing > NOP > CALL Delay2 > GOTO dodod > > END >-------- > >Well, what is happening is that the motor and an LED are turned and remain >on as long as the pin 1 on porta remains low. That is all good. The >problems happen when I turn the pin 1 on porta to high, the motor and the >LED seem to stop. BUT then a reset happens to the chip and hence it >oscillates, and never stopping. > >NOTE: motor is controlled by H-bridge (74F139) > >I don't want the chip to restart when the motor is turned on! I am propably >doing something wrong! > >At the momment I have MCLR of the PIC through a 1K resistor to high, and an >0.1 capacitor to a low. The Vdd is connected to a high. Vss is connected to >a low. >Across my 5V regulator I have a 1000uF capacitor. >Across the Vdd and Vss I have connected a 0.1uF cap. > >NOTE: the motors only require 2V, >30mA to run. > >I have checked all of the voltages on both the chips and they are both at >5V. > >Can someone help me in setting the circuit up such that PIC does not reset! >I need to get this running by tonight, and I am having no luck. > >I will continue to test and if I get any progress I will let the list know, >but so far I have been having no reset. > >I thank everyone for the help. > >------------- >Sep. S. >.....meKILLspam@spam@sep.2y.net >----------- </x-flowed>

Hello, Sorry I forgot to mention the watchdog timer is off. here is the initialization of the code: -------- #include "P16F84.INC" ; Include header file LIST P=16F84, R=DEC ; Use the PIC16F84 and decimal system __config _RC_OSC & _WDT_OFF & _PWRTE_ON and the rest of the code is as posted. ------- ---------- > From: John A. Craft <craftKILLspamNCS-SSC.COM> > To: .....PICLISTKILLspam.....MITVMA.MIT.EDU > Subject: Re: prevent unwanted reset (used to be "Help me please!!") > Date: Tuesday, February 22, 2000 4:45 PM > > I would suggest turning off the watchdog timer or clearing it from time to {Quote hidden}> time. > > John C. > At 03:34 PM 01/16/1980 -0400, you wrote: > >Hello, > >[RE: "help me please!!" messages] > > > > > >To refresh memmory I am running the following code: > >------------- > >Main > > MOVLW h'06' ; turn on an LED and a motor (h-bridge) > > MOVWF PORTB > > NOP > > > >WaitHere > > CALL Delay2 ; simply delay a little (it runs ok!) {Quote hidden}> > BTFSC PORTA,1 ; if pin 1 of porta goes high... turn > > everything off > > GOTO Finish > > GOTO WaitHere > > > >Finish > > CLRF PORTB ; NEVER PASSES THIS STAGE SINCE > > IT IS RESETING! > > > >dodod ; loop doing nothing > > NOP > > CALL Delay2 > > GOTO dodod > > > > END > >-------- > > > >Well, what is happening is that the motor and an LED are turned and remain > >on as long as the pin 1 on porta remains low. That is all good. The > >problems happen when I turn the pin 1 on porta to high, the motor and the > >LED seem to stop. BUT then a reset happens to the chip and hence it > >oscillates, and never stopping. > > > >NOTE: motor is controlled by H-bridge (74F139) > > > >I don't want the chip to restart when the motor is turned on! I am propably > >doing something wrong! > > > >At the momment I have MCLR of the PIC through a 1K resistor to high, and an > >0.1 capacitor to a low. The Vdd is connected to a high. Vss is connected to > >a low. > >Across my 5V regulator I have a 1000uF capacitor. > >Across the Vdd and Vss I have connected a 0.1uF cap. > > > >NOTE: the motors only require 2V, >30mA to run. > > > >I have checked all of the voltages on both the chips and they are both at > >5V. > > > >Can someone help me in setting the circuit up such that PIC does not reset! > >I need to get this running by tonight, and I am having no luck. > > > >I will continue to test and if I get any progress I will let the list know, > >but so far I have been having no reset. > > > >I thank everyone for the help. > > > >------------- > >Sep. S. > >EraseMEmespam_OUTTakeThisOuTsep.2y.net > >-----------

Do you inadvertently have the watchdog timer enabled? Regards, Jim On Wed, 16 January 1980, sep wrote: {Quote hidden}> > Hello, > [RE: "help me please!!" messages] > > > To refresh memmory I am running the following code: > ------------- > Main > MOVLW h'06' ; turn on an LED and a motor (h-bridge) > MOVWF PORTB > NOP > > WaitHere > CALL Delay2 ; simply delay a little (it runs ok!) > BTFSC PORTA,1 ; if pin 1 of porta goes high... turn everything off > GOTO Finish > GOTO WaitHere > > Finish > CLRF PORTB ; NEVER PASSES THIS STAGE SINCE IT IS RESETING! > > dodod ; loop doing nothing > NOP > CALL Delay2 > GOTO dodod > > END > -------- > > Well, what is happening is that the motor and an LED are turned and remain > on as long as the pin 1 on porta remains low. That is all good. The > problems happen when I turn the pin 1 on porta to high, the motor and the > LED seem to stop. BUT then a reset happens to the chip and hence it > oscillates, and never stopping. > > NOTE: motor is controlled by H-bridge (74F139) > > I don't want the chip to restart when the motor is turned on! I am propably > doing something wrong! > > At the momment I have MCLR of the PIC through a 1K resistor to high, and an > 0.1 capacitor to a low. The Vdd is connected to a high. Vss is connected to > a low. > Across my 5V regulator I have a 1000uF capacitor. > Across the Vdd and Vss I have connected a 0.1uF cap. > > NOTE: the motors only require 2V, >30mA to run. > > I have checked all of the voltages on both the chips and they are both at > 5V. > > Can someone help me in setting the circuit up such that PIC does not reset! > I need to get this running by tonight, and I am having no luck. > > I will continue to test and if I get any progress I will let the list know, > but so far I have been having no reset. > > I thank everyone for the help. > > ------------- > Sep. S. > mespam_OUTsep.2y.net > ----------- @spam@jimKILLspamjpes.com

Hello, I have tested the H-bridge of off the circuit (with the PIC removed) and it is operating just fine given one of the two combinations for each motor (1,0) & (0,1). Now, I became suspicous of my circuit and took the pic over to a breadboard and did a few tests. The following is run: -------- Start Initialize CLRF PORTA ; initialize porta CLRF PORTB ; initialize portb ; move into bank 1 BSF STATUS,RP0 ; Select bank 1 (bit #RP0 from the status register) CLRF TRISB ; Select Output on all PORTB bits MOVLW 0x1F ; set all 5 input pins as INPUT MOVWF TRISA ; put this into effect into porta BCF STATUS,RP0 ; Select bank 0 (always remember to come back!) CLRF PORTB Main CALL Delay2 MOVLW h'02' MOVWF PORTB ----------- All that works just fine, but the following code never gets run: ----------- AAA CALL Delay2 MOVLW h'04' MOVWF PORTB CALL Delay2 GOTO Main END --------- And hence I create a flashing LED on portb<1>. This obviously means that it gets to the location AAA and resets? But the MCLR is connected on the breadboard to a 4.7K resistor to the 5V regulated. So, as I can see it I don't see what the heck the problem is. Watchdog is turned off at the beginging of the code. The motors are not the problem since it operates the same with or without the motors. (BTW, these motors are tiny 1.4 cm long!!) I am coming down to the conclusion that maybe my PIC is fried but it seems to be burning fine and veryfing in the programmer. (I don't have another F84 available!!) If you can help please help. I am going to stay up all night to get it running for my presentation tomorrow. Thanks alot. -------- Sep S. KILLspammeKILLspamsep.2y.net --------

Uhm, some of the early memory positions are very special and should be jumped over *BEFORE* the start of your code. Put the line - org 06 in front of your Start statement to cause your program origin to be the 6th program word. Note - position 04 is the interupt vector, so when an interupt occurs the program jumps to this point where the author *SHOULD* have put a GOTO xxx to handle the interupt. Your program probably loops back to the CLRF TRISB statement, then continues on turning the LED back on, then another interupt (from who knows where) occurrs throwing the program back to statement 04 . . . . Just some thoughts. Bye. > {Original Message removed}