pic16f84 port A4 problem

[shahrol_hisham]

Hi i have write a program for this mc when i set the ra4 port it only set for a while only after that it reset back. i have used pull up resister but the efect is same can some one help me.

 

[glenjoy]

Post your code so at least we can check it.

 

[Lepidoptera_ece]

you can also check if the watchdog is enabled.... it will reset your micro each time a timeout occurs...

 

[platonas]

Also, have in mind that port A4 is an open collector and it needs a pull-up resistor. Otherwise it cannot drive a load to high levels.

 

[bzx]

Configure several or all pins as digital inputs

bcf STATUS, RP0
bsf STATUS, RP0

movlw 0x06
movwf ADCON1

bcf TRISA, RA4 ; Set RA4 as output

 

[C-Man]

movlw 0x06
movwf ADCON1

PIC 16F84 does not have an ADC and register ADCON1 is not implemented ...

best regards

 

[glenjoy]

Make sure your Timer0 is disabled when you are not using it.

 

[bzx]

movlw 0x06
movwf ADCON1

PIC 16F84 does not have an ADC and register ADCON1 is not implemented ...

best regards

Certainly, i was not right. Sorry

 

[shahrol_hisham]

I used the timer 0 as real time counter. so it cannot disable. It is posible that timer0 can interrupt the ra4 function ? if yes how can i solve this problem.

 

[gidimiz]

Hi,

I used the timer 0 as real time counter. so it cannot disable. It is posible that timer0 can interrupt the ra4 function ? if yes how can i solve this problem.

Be sure that your TMR0 is set correctly. Re-Check that in the OPTION_REG REGISTER (ADDRESS 81h) Bit 5, TOCS is set to 0 ( Zero ).
If you dont, then the program will reset you bit back to input when tyou set this register back to default.

Good luck.