Searching \ for '[PIC]: Programmer unreliable' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devprogs.htm?key=programmer
Search entire site for: 'Programmer unreliable'.

Exact match. Not showing close matches.
PICList Thread
'[PIC]: Programmer unreliable'
2003\02\17@164829 by Gavin Jacobs

flavicon
face
I am just starting out with PICs. I look in the FAQs and tried a Google/News search first, but I didn't see the answer. Here's my
problem.

Problem:
I am using the Olimex PG1 programmer on an Olimex P18B board, with a PIC 16F628/20. I am using MPLAB  and ICPROG 1.05A;  running on
Windows XP Pro.

As per the instructions, I told ICPROG that I have a JDM programmer and I enabled the Windows NT API. I have two undesirable
symptoms:

1) Sometimes I can program and verify the chip as expected, but sometimes (about 50%) it fails to verify; location varies.
2) Sometimes I program and it appears to verify, but the program doesn't run. Usually if I program the same hex file again, it
works. I have tried this several times with known good hex file, sometimes it works and sometimes it doesn't. I haven't been able to
figure out what (if anything) I am doing differently in each case.

Sounds like a problem with the programmer to me, but I'm new to PICs so I would appreciate any suggestions.
Questions that I couldn't find answers for:
a) Is there any limit to the length of the serial cable between the COM2: port on the PC and the programmer? Mine is about 2m.
b) Is there a correct sequence for connecting/disconnecting the programmer, starting/stopping ICPROG, etc.?
c) Any suggestions on how to make the programming reliable?

Gavin

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics

2003\02\17@173154 by Olin Lathrop

face picon face
> 1) Sometimes I can program and verify the chip as expected, but
sometimes (about 50%) it fails to verify; location varies.
> 2) Sometimes I program and it appears to verify, but the program doesn't
run. Usually if I program the same hex file again, it
> works. I have tried this several times with known good hex file,
sometimes it works and sometimes it doesn't. I haven't been able to
> figure out what (if anything) I am doing differently in each case.

I don't know anything about this particular programmer, but if it verifies
the chip correctly it's hard to believe the program on the chip is wrong.
I would therefore look for other sources of erratic behaviour.  Do you
have MCLR tied high?  Is the oscillator starting?  What kind of oscillator
are you using?  Are the power levels correct?  Is the PIC properly
bypassed close to its power/ground pins?


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics

2003\02\18@063720 by Howard Simpson

flavicon
face
Gavin Jacobs wrote:
>
> 1) Sometimes I can program and verify the chip as expected, but sometimes (about 50%) it fails to verify; location varies.
> 2) Sometimes I program and it appears to verify, but the program doesn't run. Usually if I program the same hex file again, it
> works. I have tried this several times with known good hex file, sometimes it works and sometimes it doesn't. I haven't been able to
> figure out what (if anything) I am doing differently in each case.

I have found that exactly the same problem with a DonTronics programmer
was caused by not supplying a high enough voltage to the programmer.
The programmer has all the voltage regulators on board, but if the
supply voltage is too low, the programming voltage can't be reached =
program failure.

Howard Simpson

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2003\02\18@231919 by Gavin Jacobs

flavicon
face
> > 1) Sometimes I can program and verify the chip as expected, but
> sometimes (about 50%) it fails to verify; location varies.
> > 2) Sometimes I program and it appears to verify, but the program doesn't
> run. Usually if I program the same hex file again, it
> > works. I have tried this several times with known good hex file,
> sometimes it works and sometimes it doesn't. I haven't been able to
> > figure out what (if anything) I am doing differently in each case.
>
> I don't know anything about this particular programmer,
GBJ> It is a JDM style programmer - see http://www.olimex.com/dev/images/pic-pg1-sch.gif

> I would therefore look for other sources of erratic behaviour.
Do you have MCLR tied high?
GBJ> Yes.

Is the oscillator starting?
GBJ> I assume so. If it wasn't, I would expect it to never work; or work on power off-on.

What kind of oscillator are you using?
GBJ> 20MHz crystal.

Are the power levels correct?
GBJ> +5Vdc measured at the chip.

Is the PIC properly bypassed close to its power/ground pins?
GBJ> 100nF near the chip. You can see the board and schematic at http://www.olimex.com/dev/pic-p18b.html

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2003\02\19@001814 by Stephen

picon face
I'm working on designing my own PIC programmer, but i have never seen that
oscillator part before, is that necessary for all chips?
{Original Message removed}

More... (looser matching)
- Last day of these posts
- In 2003 , 2004 only
- Today
- New search...