Newbie need Help 16F627a

[azmax100]

Hi all,

I have problem with my first experience with of PBP PIC
My first attemp is blink an LED.

here is my program

CMCON = 7


TRISB.1 = 0


LED VAR PORTB.1 ' alias PORTB.4 to LED

loop: high LED ' turn on LED connected to PORTB.1
Pause 5000 ' delay for 5 seconds

low LED ' turn off LED connected to PORTB.1
Pause 1000 ' delay for 1 seconds

GoTo loop ' loop and blink LED forever

My problem
The LED did not turn on but when I (accidently) touch one of the pic pin the
led will on for a while then off again.

Can somebody help me with this problem.

Really need help from all the gurus in this forum.

Thanks and regards.

[Archangel]

Do you have a crystal and capacitors attached to the OSC pins, or a resonator? Add this to your code DEFINE OSC 4 . Use 4 if you are using 4mhz xtal, if you are using faster xtal you will need to change your default config statement to accept it.

[Bruce]

Kind of sounds like you left the /MCLR pin floating.

[Archangel]

Kind of sounds like you left the /MCLR pin floating.

DOH ! I missed that one . .

[azmax100]

Hi all.
thanks for the reply.
Joe S. I'm using 20mhz xtal. After Define still the same.

Bruce what should i do with the MCLR pin. I am totally zero with PIC but have some experience with BS2.

[Archangel]

Hi all.
thanks for the reply.
Joe S. I'm using 20mhz xtal. After Define still the same.

OK 20 mhz will not work with the default config statement, to use 20 mhz you must change it or comment it out of the PIC16F627A.INC file located in the PBP Directory. The Default config is set to use XT_OSC and the 20 mhz requires HS_OSC, what it does internaly is to provide the oscillator with more power, as it is needed to run that fast. Study this link : http://www.picbasic.co.uk/forum/showthread.php?t=543 As for the MCLR PIN tie a resistor about 5k ohm from mclr to thr 5v+ supply. To reset the PIC you then momentaraly ground it, OR in the config statement you turn it off and use it as an I/O.