Project idea: Open-source graphing calculator?

[SiliconWizard]

Power consumption of eInk displays is not necessarily as favorable as it may seem though.

Whereas they can use as little as ZERO power while displaying a static image (you can just shut them down), they use quite a significant amount of power for refreshing their content (often significantly more than a typical LCD display), and refresh times can be quite significant. So they are worth it only if the display changes infrequently - a scenario here which entirely depends on how you use the calculator. A scenario where you launch any calculation/graph/whatever that would  take a while to read (so you'd need the display to remain ON for a longish time while being static) would be favorable, but otherwise that may not be that interesting. For many other scenarios, you could just save power by automatically shutting down the display after a configurable time-out, and powering on again on the press of a key, or touch of the screen or whatever. You can also use (as Swissmicros did with their latest calc) a memory LCD display which draws extremely little power (to the point of being able to leave it on while the calc is off, with a static image, while drawing insignificant power from the battery...)

Doesn't Sharp have their own version of "eink" that refreshes somewhat faster?

I think that is exactly what I refered to above as "memory LCD". https://www.sharpsma.com/products?sharpCategory=Memory%20LCD
(I'm not aware of any other kind of similar displays from Sharp, maybe there is though.)

As I said, Swissmicros used one in their latest products: https://www.swissmicros.com/products
(DM42, DM41X)

I also used one in a project (some kind of weather station). They look great and draw very little power. They are nothing like eInk actually, and are much closer to conventional LCDs. They have fast refresh, but at the same time can hold static content (so between changes) with only minimal current.

[tooki]

Never tried any HP calculator before, but I have just found that the new HP Prime G2 has a superior CAS-engine and it's full of powerful features

I have it and it’s a great calculator.

Umm, as ergonomics nothing can beat the Casio FX9860GIII (with ucPython)

Unless the Casio also has tactile keys, then its ergonomics are inferior to the HP Prime.

and there is nothing similar to the "Casio FIX/SCI/ENG display" (love it);

What’s so special about that? The HP Prime has all of those display modes and several more.

the new Prime G2 is bigger, less "pocket" and also very expensive (200-250 euro), but it's really an awesome super-calculator! And it's also very very fast!

The HP Prime is smaller in every dimension than the FX9860GIII. And I don’t know where you pulled out that price number: it costs around 135 euros.

It is fast though!

Yes, but also the price is different. The HP Prime G2 costs 2 times the CASIO GX8960GIII, and note: not all the CAS calculators are admitted to examinations, whereas all the non-CAS graphical calculators are usually admitted to examinations.

Local vendor here in CH:
HP Prime: 135 CHF
FX8960GIII: 119 CHF

Amazon.de:
HP Prime: €149
FX8960GIII: ~€110 including case

Amazon.co.uk:
HP Prime: £132
FX8960GIII: £99


Yes, the HP Prime is more expensive, but not by the absurd amount you claim.

[tooki]

Stupid Alpha layout?

A-Z rather than QWERTY.

Makes text entry annoyingly slow for anyone who knows how to type.

Other kind of limitations?

Little or no communication features, often specific calculations left out, etc. (That's why TI has so many nearly-identical models. For example, many have a "plus" and "pro" version that differ only in the "plus" version lacking a few functions that are banned at a particular school level.)

[DiTBho]

absurd amount

This is what ePrice lists for the calculator.

I didn't check Amazon.

[DiTBho]

What’s so special about that? The HP Prime has all of those display modes and several more.

CASIO is inferior for a lot of reasons, but the ENG display feature is something I have never seen in any TI and Sharp calculators that I have ever owned or tried. For instance I owned a TI89, liked it when I was a student for its CAS that helped me a lot studying math and physics, but for recent daily stuff I seriously love how my CASIO represents numbers when I need then in the ENG format.

ENG means if you type 1.000.000, the calculator represents it as "1M"

That's so beautiful when you deal with electronic stuff. Pico? Fempto? Nano? Milli? In a matrix of number to evaluate something? That's it, you have a comfortable menu with all the ENG-symbols, so you type them in ENG-format, the engine elaborates its stuff, and boom, you get the solution in vector form and displayed in ENG mode.

Fantastic!

The HP Prime is smaller in every dimension than the FX9860GIII

Calcuso sells protective-cases for calculators, according to them
The HP Prime v2 should be something like 14x86x182 mm
The CASIO FX9860GIII should be something like 19x84x176 mm
Umm, not so bigger, as a matter of fact.

[DiTBho]

A-Z rather than QWERTY.
Makes text entry annoyingly slow for anyone who knows how to type.

yeah, then you want a keyboard like this

[ttx450]

did not read the whole thread.  This is my graph cal.. Ti-92  it is older. 

Not sure what you are wanting to do, but maybe rooting one of these might work if you are trying to install your own OS.  I rooted phones, not sure about this.  This was expensive back in the day and have no reason to screw with it as it works fine.  they might be cheap now.

[tooki]

What’s so special about that? The HP Prime has all of those display modes and several more.

CASIO is inferior for a lot of reasons, but the ENG display feature is something I have never seen in any TI and Sharp calculators that I have ever owned or tried. For instance I owned a TI89, liked it when I was a student for its CAS that helped me a lot studying math and physics, but for recent daily stuff I seriously love how my CASIO represents numbers when I need then in the ENG format.

ENG means if you type 1.000.000, the calculator represents it as "1M"

That's so beautiful when you deal with electronic stuff. Pico? Fempto? Nano? Milli? In a matrix of number to evaluate something? That's it, you have a comfortable menu with all the ENG-symbols, so you type them in ENG-format, the engine elaborates its stuff, and boom, you get the solution in vector form and displayed in ENG mode.

Fantastic!

OK, I see. While I'd love to have that mode, "engineering notation" is generally understood to mean x.xxxxEⁿ (i.e. x.xxx*10^n), with n being a multiple of 3.

The HP Prime is smaller in every dimension than the FX9860GIII

Calcuso sells protective-cases for calculators, according to them
The HP Prime v2 should be something like 14x86x182 mm
The CASIO FX9860GIII should be something like 19x84x176 mm
Umm, not so bigger, as a matter of fact.

You're right, the website I was looking at has the size of the Casio wrong. With that said, it's only a small difference in footprint, and the HP is 25% thinner, so extremely similar volume.

[tooki]

A-Z rather than QWERTY.
Makes text entry annoyingly slow for anyone who knows how to type.

(Attachment Link)
yeah, then you want a keyboard like this

In a way, yes! (Though given TI's general lack of ambition in keypad design, I don't expect it'd be a particularly good keyboard… :/)

Interestingly, it looks like modern TI calcs support USB keyboards!




I'll have to dig out a USB OTG adapter and see if the HP supports one...

[DiTBho]

Though given TI's general lack of ambition in keypad design, I don't expect it'd be a particularly good keyboard…

I happen to own one of these keyboard, found on eBay for 20 bucks shipped, practically a bargain you can't let go. It looks and "sounds" of the same quality as a cheap membrane keyboard. Nothing special, but not too bad.

[ttx450]

That's one of the few projects I don't see any use for, but that's probably only me 
To me a calculator is a tool like a hammer (or a scope or...), I have 3 27 inch monitors at my workstation and a mobile. If I need a graphing calculator, I start one up on one of the many screens here....
If I need to take it with me, I have my phone.
I just don't get it ?

there use to be a ton of online cal tools.. sure mnay more now..  very nice tools.  my 92 is for fun and makes me feel smart

then again I am into old computers

[DiTBho]

a calculator that specializes in curve fitting ?

is there any opensource like these?

[technix]

did not read the whole thread.  This is my graph cal.. Ti-92  it is older. 

I have a similar unit - TI Voyage 200, which is basically the TI-89 Platinum to TI-92 and original TI-89. You can module upgrade it to a TI-92 Plus, which opens up a bunch of new features.