[Reviving this thread..]
Posted by TomL on 4 June 2010, 8:29 p.m.:
Quote:
I read about the repurposing project for the HP12c and was wondering if anyone has updates?
I'd rummaged around there about a year or so ago
with interest to see that move forward. I'm curious
what may have throttled the effort?
Posted by Katie Wasserman on 5 June 2010, 12:31 a.m.:
Quote:
The 20b SDK won't work on the 12C+, only the CPU is the same the peripherals are all different, but there is an SDK of sorts (sample program actually) for the 12C+
I thought the 12c+ was designed around an AT91SAM7L128
(maybe ~L64) COB, is that correct? If true there isn't
much in the way of 12c+ specific peripherals aside from
the keyboard matrix and the LCD controller on ports A and B.
Shouldn't be too difficult to puzzle out the interconnect.
The key matrix can be mapped with a scan of port C, the
LCD with a scan of A & B. I have a disembodied 12c+
LCD glass which I'd be willing to map out to help the
effort.
Or am I missing some subtle design caveat here for the
12c+?
Posted by Katie Wasserman on 5 June 2010, 12:38 a.m.:
Quote:
Pogo pins are pretty easy to find maybe even in 2 x 3 arrangements. But unless you can create some sort of locking plug it's going to be hard to hold the connector in place while programming.
Unfortunately the 12c+ 2x3 contact grid is on 2mm centers.
At least last time I rummaged for metric pitch pogos I
didn't get anywhere as most are 100mil pitch which
even if disassembled didn't look conducive to relocating
on a 2mm pitch. I just saw MillMax has 50mil pitch pogos
which could be made to work. But I'd only do so if I
really needed a stand-alone connector which could lock
to the keys molded in the housing. Even then you'd have a
rather awkward package if you were planing on using the
keyboard.
I'd probably just build a horizontal fixture and use stainless
steel spring wire bent into a long "L" shape as contacts.
That will give enough contact tension to make a reliable
connection and the calculator would be able to sit at a
low profile.
Posted by Scott Newell on 5 June 2010, 1:40 a.m.:
Quote:
If I was to build a fixture or cable from scratch, I'd seriously consider using the PC's serial port handshake lines to control the erase and reset pins... If only you could hit the on key through the cable, the whole programming process could be automated.
Is there anything needed to program flash besides communicating
with the SAM-BA via the DBGU port? From my scan of the AT91SAM7L
manual it appears the rom provides all needed functionality.
I have a bunch of AT91SAM7L128 samples lying around which I
was planning to use. But if a 12c+ doesn't have a functionally
modified AT91SAM7 use of that package is faster (and cheaper)
than creating a throw away board layout.
Thanks!