Yeah, I have two Dell power adapters in which the ROM apparently has gone
bad. They will power my notebook, but will not charge it.

The first adapter died at about 3 months age, Dell replaced it (but did not
require its return). The replacement died about 6 months after that. Again,
Dell replaced it without requiring return.

So, now I have 3 adapters, one of which works perfectly and the other two
which won't charge.

~ Bob Ammerman
RAm Systems

> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf
> Of Robert Dvoracek
> Sent: Tuesday, November 11, 2014 8:40 PM
> To: Microcontroller discussion list - Public.
> Subject: RE: [EE]:: Securely encrypt your batteries with HMAC SHA-1
>=20
> DeLL puts a 1-WireRT ROM in the power brick as well in an attempt to bloc=
k
> unauthorized power adapters.  It's a funny little TO-92 device with one o=
f
the
> pins cut off.  The reasons for going with through-hole over SMD when it
> would be the obvious choice in this case are a bit mysterious.  Maybe the=
y
> got a good deal on them, who knows.
>=20
> > Date: Wed, 12 Nov 2014 12:24:36 +1100
> > From: quozl@laptop.org
> > To: piclist@mit.edu
> > Subject: Re: [EE]:: Securely encrypt your batteries with HMAC SHA-1
> >
> > On Wed, Nov 12, 2014 at 12:28:15AM +0000, Nicola Perotto wrote:
> > >
> > > On 11/11/2014 23:15, RussellMc wrote:
> > > > 'This product is intended only for use with the high quality [tm]
> > > > over-priced batteries sold by xxx corporation.' Which may be of
merit in
> some cases :-).
> > > > For some values of 'merit' R
> > >
> > > My 5 years old D3ll notebook has already a very similar feature...
> > > in the
> > > charger: if it's not original you can charge the battery and the
laptop runs
> slowly.
> > > They use a 1-wire 64 bit ID chip that has low security and can be
> > > cloned :-)
> >
> > Same here.  We use a DS2756.  One of the EEPROM bytes contains our
> > battery chemistry identifier.  Our charger firmware won't charge the
> > battery unless that identifier matches one of the algorithms we have.
> >
> > Interesting things may happen if the identifier is wrong; 'cause we
> > support NiMH as well as LiFePO4.
> >
> > We're adding LiPoly now.  I've been busily testing samples.
> >
> > http://dev.laptop.org/git/users/rsmith/ec-cl4_ras/log/?h=3Dlipoly
> >
> > --
> > James Cameron
> > http://quozl.linux.org.au/
> > --
> > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
>=20
> --
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist

--=20
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