Why is my LED not blinking?

[Jumper]

And you have a resistor (470 ohm) connected to the LED so you dont fry it?

And you have tested the LED that it is working by connecting it thru a resistor to the powersupply?

Checked that you have VDD availible at the PIC and that VSS really connects to the power supply?

What if you connect a resistor and LED across the PIC VDD and VSS lines, then it should turn on when you start your power supply.

As you said it is probably something stupid, and then this might be something to start with.

And dont forget to disconnect the incurcuit programmer since that one will hold the PIC in reset.

/me

[Gary Goddard]

The led lights fine if connected to the pic vdd so its all waiting there for the pic to wake up. That's what I mean; it should work yet no life.

[skimask]

The led lights fine if connected to the pic vdd so its all waiting there for the pic to wake up. That's what I mean; it should work yet no life.

Does you programmer have a verify chip function (it should, but I figured I'd ask anyways)? I've got a Warp13 and one thing that's tripped me up in the past is turning off the verify function 'cause I assumed it was programming a chip, then after hours of trying to figure out what's wrong, I find my programmer cable dangling over the edge of the table. It didn't tell me the chip wasn't programmed 'cause it didn't check! Go figure, but it happens...

Have you tried putting one chip in, program it, pull it out, try a verify, which obviously should fail, then put a seperate chip in (same type of course), try a verify, again, should fail. If they don't, the programmer might not actually be programming...maybe, perhaps? could happen...

Watch the PGC and PGD pins during programming on a 'scope (assuming you have one)? The PGC should be cycling regularly and PGD quite erratic. Make sure the MCLR gets pulled all the way up to +12v during programming?

Just a smathering of a few ideas flustered forth from my fingers for ya....

Do you have a 'scope? Have you 'scoped the resonator pins? Anything? Or just put a meter on the pins to ground, should have about 1.5-ish volts on them with power.

[Archangel]

Hi Gary,
here is your blinky, this code works as is.
it's your code with some add ins, after you check what skimask suggested,
try this and it should work, then remove parts of this code until it stops working and see what you learned. I think it is the trisb setting your code needed. The chip just didn't know whether to input or output.
JS

@ DEVICE pic16F84, XT_OSC

@ DEVICE pic16F84, WDT_OFF
' Watchdog Timer

@ DEVICE PIC16F84, PWRT_ON
' Power-On Timer

DEFINE OSC 4


TrisB = %00000000    ' Sets all bits portb as outputs

loop:
High PORTB.0 ' Turn on LED connected to PORTB.0
Pause 1500 ' Delay for 1.5 seconds

Low PORTB.0 ' Turn off LED connected to PORTB.0
Pause 1500 ' Delay for 1.5 seconds

Goto loop ' Go back to loop and blink LED forever
End

[Jumper]

High and low are according to the PBP manual supposed to set the pin automaticly to an output.

But I guess it is good practise to to it your self

/me

[Gary Goddard]

Ok, pgc on oscilloscope peaks at 5V or so in reg intervals, pgd also active, mclr is at 14 volts during programming, programmer verifies, ceramic resonator is resonating. Stuff is going in that black box just nothing out of it. I have also tried changing the chips, port numbers, used a 16F84, 16F88, 12F675. I have even changed the breadboard. What else can I do?

[paul borgmeier]

- Can you post a schematic or picture of your setup?
- Your diode is not reversed? (take it out and measure port with DMM while "running")
EDIT - As Skimask suggested, is your resonator resonating after you program - I think you tell us it does during programming but how about when you try and run your chip - is it resonating?