Welcome into PIC world

[ScaleRobotics]

The hex files seem to be the same. After compliling, I get one like post #13 if I look at the format my MeLabs programmer displays, but the hex file it uses looks just like post #15. So we must all be compiling the same thing. At least that's something! I have not been able to find my pic16f84a. I have not used those for a long time. The 16f84a has so few settings to begin with, that there isn't a lot to get wrong in the config fuses.

I saw that you have your osc set to 4 mhz. Can you confirm that your resonator is really 4 mhz? If it was 8 to 10 mhz, you should be setting it for HS and not XT.

By the way, do you have any other resonators, or crystals you could try?

[shafi008]

Hi I have the following
a). 4.00 GR
b). F0x040A 4.000 (with this i tried 4.7 / 220 / 10 PF's)

i tried with both , may i will try with a new Pic16f84a.
I dont get it when i take off the VSS then the led is constantly lighted up.

if i keep the multimeter to the pin RB0 then the light comes up steadily.
power at that time would be 0.79 and at MCLR to VSS it is 1.24 volts.

should i change the watchdog / powerup timer ON. and try...?
how much power should i get at the pin?

[shafi008]

Here is the code in MCS

@ DEVICE pic16F84A
define OSC 4
TrisB = %00000000

loop:
High PORTB.0 ' Turn on LED connected to PORTB.0
Pause 1000 ' Delay for .5 seconds

Low PORTB.0 ' Turn off LED connected to PORTB.0
Pause 1000 ' Delay for .5 seconds

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


when the MeProg popsup the hex values are as follows,

0000- 2828 018f 008e 30ff 078e 1c03 078f 1c03
0008- 2823 3003 008d 30df 200f 2803 018d 3ee8
0010- 008c 098d 30fc 1c03 2818 078c 1803 2815
0018- 078c 0064 0f8d 2815 180c 281e 1c8c 2822
0020- 0000 2822 0008 1383 1303 1283 0064 0008
0028- 1683 0186 1283 1406 1683 1006 1283 3003
0030- 008f 30e8 2002 1006 1683 1006 1283 3003
0038- 008f 30e8 2002 282b 0063 283c

but when i program it then the values changes and displays like this.

0000- 003c 018f 008e 30ff 078e 1c03 078f 1c03
0008- 2823 3003 008d 30df 200f 2803 018d 3ee8
0010- 008c 098d 30fc 1c03 2818 078c 1803 2815
0018- 078c 0064 0f8d 2815 180c 281e 1c8c 2822
0020- 0000 2822 0008 1383 1303 1283 0064 0008
0028- 1683 0186 1283 1406 1683 1006 1283 3003
0030- 008f 30e8 2002 1006 1683 1006 1283 3003
0038- 008f 30e8 2002 282b 0063 283c


is it right?

[ScaleRobotics]

Your resonator probably has 15 pf, which is within what the data sheet says it should be. The 10 pf caps you have do not quite meet the data sheet specs for the other crystal you have. I do not know whether this would mean it won't work, or if it just would not be ideal (probably not ideal).

I think that mclr should be very close to vdd. So if it is just 1.24v or so, something is wrong. What is your vdd voltage? Is it also 1.24v?

Sounds like the voltage is the problem.

[shafi008]

VDD is 5.08 volts.
at mclr one side it is giving 5.08volts and the other side where the pin 4 is connected it is 1.24 volts.

[ScaleRobotics]

Well, not sure what is causing it, but on an healthy chip, you should be seeing between 4 and 5 v on the mclr pin. If you seem to be having enough voltage everywhere else, with no outputs from the chip accidentally going directly to ground, etc, then it seems like you have an unhappy PIC.

[Archangel]

Hi I have the following
a). 4.00 GR
b). F0x040A 4.000 (with this i tried 4.7 / 220 / 10 PF's)

i tried with both , may i will try with a new Pic16f84a.
I dont get it when i take off the VSS then the led is constantly lighted up.

if i keep the multimeter to the pin RB0 then the light comes up steadily.
power at that time would be 0.79 and at MCLR to VSS it is 1.24 volts.

should i change the watchdog / powerup timer ON. and try...?
how much power should i get at the pin?

If you disconnect VSS the power flows through the PIC as though it were a resistor. I compiled with default configs, powerup timer enabled and WDT on. Have you tried reading back your hex from the PIC ? Maybe it is not programming at all. That could happen if the wrong COM port is selected, or programmer is jumpered wrong.
EDIT: try copy paste the hex I posted into your programmer and see if it blinks. BTW WDT and Power up timer are actually good things unless they somehow interfere (like when using sleep) Powerup allows PIC to wait for power to get stable B4 booting up and WTD resets a stalled out PIC.

[Archangel]

OK I just downloaded ME PROG and set it up . . and that is where the hex you are using came from, it is a default sample hex, not your hex.
When you click File . . . Open . . . The window that opens will list a directory tree and file name. You have to direct it to YOUR hex file located in Your PBP directory in whichever subdirectory you chose to save YOUR code in. That is why it is not working for you . . . Damn, it is the same . . . Hmmmm . . . OK again maybe the programmer isn't programming due to incorrect port.