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Anybody read a good manual lately?
03-09-2014, 11:44 PM
Post: #12
RE: Anybody read a good manual lately?
(03-02-2014 08:08 AM)Steve Simpkin Wrote:  Dale,
The RPN calculator project you are working on sounds very fascinating! I (and many others here) really like the horizontal format used in the Voyager models and an expanded display would really be unique for this format. Please keep me (and all of us) updated as its status changes. I had a lot of fun following the WP34S along its development path and the one I have is one of my favorite calculators. I am really excited about the RPN DIY calculator projects that have come up in the last few years.



Many thanks for your very kind words and encouragement. You too, Matt and everyone on this thread.

Attached are photos of my "first development prototype" used to prove out some keyboard scanning and display stuff.


This first try is with a Freescale MCF51JM128, which is a 32-bit microcontroller (pin compatible with a similar 8-bit machine) with USB, etc., etc. But I plan on using a SiLabs SiM3U1xx series chip -- lower power, more memory, etc. I've also drawn up preliminary schematics for LiIon battery charge control, USB interface, IR LED for printing, SDCard socket, RTC chip and FRAM for program storage. So I need to remove the DEMOJM board and hook this up to my SiLabs board. The display is an EA DIP204J-4NLW -- it costs more than most folks would pay for a calculator, but I like it a lot. The driver on it talks 4 or 8 wire parallel (like most), plus SPI, which is handy. Nice black text and white LED backlight.

In later versions, the display will be on the left (as I am a right-handed user), and the four "arrow" keys in the diamond will be on the right. As Walter and I discussed many moons ago, that lets me use the first six keys on the upper row as ABCDEF for hex number entry (16C style). And they'll be smaller, all surface-mount except the display.

The keyboard layout lends itself to QWERTY operation -- the centered ENTER^ key (upward arrow mandatory, like my HP-25!) doubling as a spacebar. The chip has UARTs on it, so if this were ten years ago, I'd add one or two RS-232 ports -- but likely not worth the effort now...

My goals for the firmware are a bit different from what I see on the 43S / 34S. I see those more as "full-function" machines, with lots of stats, distributions, probabilities, high-end math stuff. I see this as more of a cross between 16C and 29C. I doubt I'll develop much more than basic log, trig, math and line fit for functions. The emphasis will be on programming, and the data type model will be much like the industrial controllers I use at work: various sizes of unsigned and signed integers and IEEE floats, and bools. Lots of tools for type conversion, comparisons, boolean logic, etc.

Hope this helps you understand where I'm going.

p.s.: This actually HAS 43 buttons.....What's the 41 / 43S have --- 39 if you count the four at the top for power, etc.?
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RE: Anybody read a good manual lately? - Dale Reed - 03-09-2014 11:44 PM

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