Forums

16f877 cant use ICSP

Started by Unknown November 14, 2004
On Sun, 21 Nov 2004 12:43:06 -0700, michaelerath wrote:
>Well looks like microchip screwed me.

I seriously doubt that.

>I tried several programmers and then borrowed a friends picstart.
>None of the chips I ordered work. They are all dead from the factory.
>I think im done with microchip.

That would be your loss then.

>Has anyone else had this problem?

I've been doing electronic design work professionally for about 25
years now. I can count on one hand the number of times I've had chips
from *any* manufacturer that were "bad out of the box". In fact, it's
been at least a decade since that's happened. I've never gotten a bad
chip from Microchip.

IC's are very rarely bad. They occasionally go bad when you do
something -- known or unknown -- to them. If your chips don't work,
start by assuming you did something bad to them and don't just keep
pumping new chips into the same circuit (or programmer in your case)
assuming the chips were bad and things will change. They rarely do. If
I have a circuit and the first IC doesn't work I may try a second. If
the second doesn't work I stop there and try to figure out what I did
wrong or where the problem is.

Matt Pobursky
Maximum Performance Systems




It's a pretty big leap from
"I can't make it work" to
"microchip screwed me"
don't you think?

I think the clue might be in the "several programmers".

mike

--- In , "michaelerath" <michaelerath@n...> wrote:
> Well looks like microchip screwed me. I tried several programmers and
> then borrowed a friends picstart. None of the chips I ordered work. They
> are all dead from the factory. I think im done with microchip.
> Has anyone else had this problem?
>
> Michael > -----Original Message-----
> From: rtstofer [mailto:rstofer@p...]
> Sent: Sunday, November 14, 2004 10:08 AM
> To:
> Subject: [piclist] Re: 16f877 cant use ICSP >
> The programming algorithm for the 877A is completely different than
> the 877. Unless your software states that it can handle the revised
> strategy, it probably won't.
>
> More details are available by comparing the datasheets of the 877 and
> 877A.
>
> You can still buy 877s (non-A) so it isn't much of a problem.
> Unfortunately, the 877 is a little more expensive.
>
> --- In , michaelerath@n... wrote:
> >
> > Sorry, im trying to use the 877A . yes, i have 13.3v on mclr. 5v on
> > vdd and ground on vss. i was using a 21V (3x nimh 9v) supply tho
> > recently went to a 20v dc adapter .
> >
> > --- In , "Wouter van Ooijen" <wouter@v...>
> wrote:
> > > > I have built an ICSP programmer that has worked fine fro my 16f84a
> > > > both onthe board and in their circuits. But now i picked up some
> 877's
> > > > and 16f88's. both support HVP and LVP. In the doc's it states HVP
> is
> > > > active all the time and works with standard HVP programmers.
> > >
> > > The 877 (not the 877A!) is sufficiently like the F84A that most
> > > programming methods can use both. The F88 is definitely different.
> > >
> > > > I tried pulling rbs(PGM) to ground, no effect
> > > > I stepped through the signals and all voltages are normal.
> though rb6
> > > > and rb7 only hit 3.37VDC.
> > >
> > > That is very strange. I suspect you did something very wrong, like
> > > applying Ground/Vcc or MCLR to the wrong oinsw?
> > >
> > > Does the programmer (and its software) state that the 877 and/or
> F88 are
> > > supported?
> > >
> > > Do you use a nice and clean +5Volt?
> > >
> > > Wouter van Ooijen
> > >
> > > -- -------
> > > Van Ooijen Technische Informatica: www.voti.nl
> > > consultancy, development, PICmicro products
> > > docent Hogeschool van Utrecht: www.voti.nl/hvu > to unsubscribe, go to http://www.yahoogroups.com and follow the
> instructions >
>
> <http://us.ard.yahoo.com/SIG9nnpogp/M)8184.5584357.6650215.3001176/
> D=groups/S06554205:HM/EXP00538495/A$26683/R=0/SIGeeoolb0/*htt
> p:/www.netflix.com/Default?mqso`185400> click here > <http://us.adserver.yahoo.com/l?M)8184.5584357.6650215.3001176/D=group
> s/S=:HM/A$26683/rand81576968>
>
> _____
>
> > Service.



It is my loss, I've normally worked with fpgas for now. And then went to
the 16f84's. I built an icsp programmer which worked fine with my 84's
but didnt work for 877,871 or the 88's. the design doesnt change for
hvp and the software is supposed to be compatible. But wouldnt work.

When I tried my friends picstart, I used fresh 871's from the tube. it
programmed them and verified (which really is weird) but the programmer
read back as being empty (if there it failure it will report failure to
access pic). And the pics wouldnt function in cct. Now what just came
to mind is, does the PGM pin have to be pulled low for the chip to run?
If so , then that where I went wrong.

Either way. I dont know why these programmers are failing to work. I
can check out each signal and all are fine now with 0 and 5v . but when
I go into program, it flops. Hvp or lvp. (burnt out an lpt card when I
realized the 12v transistor was backwards, opps. Thats one isa card
out).

I tired keeping the line length down two 6 inches. Still no dice. Frustrated. -----Original Message-----
From: Matt Pobursky [mailto:]
Sent: Sunday, November 21, 2004 5:52 PM
To:
Subject: RE: [piclist] Re: 16f877 cant use ICSP On Sun, 21 Nov 2004 12:43:06 -0700, michaelerath wrote:
>Well looks like microchip screwed me.

I seriously doubt that.

>I tried several programmers and then borrowed a friends picstart.
>None of the chips I ordered work. They are all dead from the factory.
>I think im done with microchip.

That would be your loss then.

>Has anyone else had this problem?

I've been doing electronic design work professionally for about 25
years now. I can count on one hand the number of times I've had chips
from *any* manufacturer that were "bad out of the box". In fact, it's
been at least a decade since that's happened. I've never gotten a bad
chip from Microchip.

IC's are very rarely bad. They occasionally go bad when you do
something -- known or unknown -- to them. If your chips don't work,
start by assuming you did something bad to them and don't just keep
pumping new chips into the same circuit (or programmer in your case)
assuming the chips were bad and things will change. They rarely do. If
I have a circuit and the first IC doesn't work I may try a second. If
the second doesn't work I stop there and try to figure out what I did
wrong or where the problem is.

Matt Pobursky
Maximum Performance Systems

to unsubscribe, go to http://www.yahoogroups.com and follow the
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> When I tried my friends picstart, I used fresh 871's from the tube. it
> programmed them and verified (which really is weird) but the
> programmer
> read back as being empty (if there it failure it will report
> failure to
> access pic).

Sounds as if you might have code protection enabled.

But I'd recommend starting with zero unknowns: take a fresh chip, the
PicStart+, and a known good program. I have blink-a-led code for a lot
of PICs at http://www.voti.nl/swp. If that works change one thing at a
time.

Wouter van Ooijen

-- -------
Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: www.voti.nl/hvu