Re: Hack a 15C-le into a 16C?
Message #3 Posted by uhmgawa on 18 Dec 2011, 2:12 p.m.,
in response to message #1 by David Griffith
Quote:
Have any of you involved in the development of the WP34s given any thought to the concept of hacking a 15C-le into an emulation of the 16C?
I've been thinking to do a KEMU port to the sam7 voyagers
for some time now. But my impasse is really wanting
to displace the segment display with a graphic matrix.
It is quite possible to do so as the lcd segment controller
drive is multiplexed as gpio. However a custom module of
either COG or COB topology is realistically required. COG
provides minimal vertical elevation but has problematic
active area asymmetry, has interconnect routing issues, and needs off-glass charge pump capacitors (which could be
located on a flex pc interconnect). COB can address routing and
charge pump components allowing use of a less expensive FFC
interconnect. But a conventional
COB unit is problematic due to available
z-axis consumed via pcb, zebras, and compression frame residing
in tandem to the glass. The frame and zebras can
be displaced by heat seal tape and in doing so we don't need
a particularly ridgid pcb. It might be possible to reduce it
to 0.4mm -- however the COB encapsulant projection
could double that.
Even dismissing all the above, it is still a custom glass
prospect to optimally fill the existing window and fit within
the existing glass enclosure void. I think the quote I had for
a near ideal 192x32 unit was somewhere in the US$7-8K ballpark
which included one-time tooling and delivery of the first 1K
units.
That's a tall order and travelling this path may not make
much sense unless leveraging it as an opportunity to
provide some sorely missing features. Eg, at a minimum:
external communication, high endurance NV memory, additional RWM,
perhaps external power.. Basically what I would have hoped for
in an encore voyager 30 years later, particularly a 15c.
Anyway this is all very much possible and straightforward
with with a new pcb layout. Doing so also allows the major
simplification of freeing us from the need to
shoehorn these enhancements into the existing design.
However at this point we get to
question whether the aged sam7 is worth the effort of bringing
forward given more cost effective and higher performance
SoCs currently available.
The one consideration which
(at least to me) prevents the above tirade from being wholesale
dismissed is the
fact such a prospective board+display swap on an encore voyager
is mechanically a fairly minor undertaking.
But I suppose from my POV I don't find a clear delineation in the
slippery slope continuum corresponding to a meaningful partial
feature set. At least that's my excuse for not having pursued
a physical prototype thus far.
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