Does it really have to have keys?



#16

Regarding the hardware base for the "ultimate RPN" calc, does it *really* have to have physical keys?

What about capacitive touchscreens?

For an RPL graphics calc with a large visible stack, I'm thinking the nook comes close to perfect hardware.
One month rechargeable battery life; huge matrix display to display equations, stack, graphics, etc.

To me, having something like 30 soft-keys with labels on them and a stack I can move and interact with (pick an entry for editing by tapping it, etc.) easily beats the loss of tactile feedback.

For programming, I'm finding myself typing *a lot* faster and freer of stress on an on-screen keyboard (such as on iPhone/iPad), than on small real keys like on an 28S or an N810 (smallish keys with an QWERTY layout). I confess that, by now, I actually *like* that there's no noise or physical resistance, when I type.

The perfect dedicated calc to me would be half the size of a nook, aluminum-clad and razor thin, with shirt-pocket portability, and still sporting an Eink display. There're no EInk matrix displays smaller than 5", so I'm not holding my breath for it to come along by itself. This kind of form factor would make for a suitable base for the more classical RPN calc sought by most on this forum, with the graphics display and menus traded for lots of dedicated keys, I reckon.

Notwithstanding the question of feasibility, what do people think? Are physical keys really what the ultimate RPN calc (be it like a 42S successor, or more like a 50g successor) must have?


#17

Yes. No tactile feedback without keys. YMMV

#18

Quote:
The perfect dedicated calc to me would be half the size of a nook, aluminum-clad and razor thin, with shirt-pocket portability, and still sporting an Eink display. There're no EInk matrix displays smaller than 5", so I'm not holding my breath for it to come along by itself. This kind of form factor would make for a suitable base for the more classical RPN calc sought by most on this forum, with the graphics display and menus traded for lots of dedicated keys, I reckon.

That's not a bad idea actually.

The Sharp Memory LCD's offer extremely low power consumption. There is a 3" version. I'm using a smaller one on my new uWatch Mk2 design.

The problem is the touch screen that draws considerable power compared to the display and processor.

But designing such a hardware platform would not be too hard. I'd imagine a thin machined aluminium case with a screw on front cover to hold all the guts in, an ultra thin rechargable lithium poylmer battery with micro USB connector for charging, and maybe a micro SD card slot. Or maybe standard coin cell lithium batteries depending upon the power budget, but there goes your thickness...

Such a design would slip in a shirt pocket real easily, and would not be that hard to prototype into a really usable form I suspect.

Dave.

Edited: 19 Sept 2011, 8:00 a.m.


#19

Quote:
The problem is the touch screen that draws considerable power compared to the display and processor.

That's an interesting aspect I hadn't known about. Any ideas how the nook can still offer two months claimed battery life?
(I don't think they completely exaggerating because they'd be called out for that, as enough people compare it to the touchscreen-less Kindle, which claims a month and does 2 weeks.)
Might the digitizer enter a drawing-almost-no-power mode, while not tracking?

Are there SoCs that include the necessary logic to drive/read a touchscreen? (I imagine there are.)

Quote:
But designing such a hardware platform would not be too hard. I'd imagine a thin machined aluminium case with a screw on front cover to hold all the guts in, an ultra thin rechargable lithium poylmer battery with micro USB connector for charging, and maybe a micro SD card slot.

Yes, lovely. Your comment that it wouldn't be too hard is intriguing.

Quote:
Such a design would slip in a shirt pocket real easily, and would not be that hard to prototype into a really usable form I suspect.

Could you quantify this somewhat? What do you think it would take in dollars and time to get to prototype and final HW stage for an aluminum-clad touchscreen ARM SoC-based thing, with a micro USB (and maybe micro SD) and sole power button? (Very rough estimate to give me a ballpark idea would be much appreciated.)

My question may be grossly naive, but I'm a SW guy.

Thanks.


#20

Quote:
That's an interesting aspect I hadn't known about. Any ideas how the nook can still offer two months claimed battery life? (I don't think they completely exaggerating because they'd be called out for that, as enough people compare it to the touchscreen-less Kindle, which claims a month and does 2 weeks.) Might the digitizer enter a drawing-almost-no-power mode, while not tracking?

The usual resistive touch screens take significant power all the time. Although you could shut them off under software control.
Maybe some form of capacitive touch screen instead, I'd have to investigate.

Quote:
Are there SoCs that include the necessary logic to drive/read a touchscreen? (I imagine there are.)

Some I believe, but in any case it's fairly trivial to add capability.

Quote:
Quote:
But designing such a hardware platform would not be too hard. I'd imagine a thin machined aluminium case with a screw on front cover to hold all the guts in, an ultra thin rechargable lithium poylmer battery with micro USB connector for charging, and maybe a micro SD card slot.
Yes, lovely. Your comment that it wouldn't be too hard is intriguing.

It shouldn't be, I've gone through the motions with my calc watch projects.
It's just a matter of getting a suitably thin case machined.

Quote:
Quote:
Such a design would slip in a shirt pocket real easily, and would not be that hard to prototype into a really usable form I suspect.
Could you quantify this somewhat? What do you think it would take in dollars and time to get to prototype and final HW stage for an aluminum-clad touchscreen ARM SoC-based thing, with a micro USB (and maybe micro SD) and sole power button? (Very rough estimate to give me a ballpark idea would be much appreciated.)

I can give you a reasonably accurate ballpark.

Rather than guess, I did a quick case design in eMachine shop, and the price comes out at $265 for 10 cases custom machined in 6063 aluminium, not including a backing panel. Includes shipping to Australia. $175 without shipping.

But that is a crude model, lets up that to say $300 for a more refined one with tapped holes for the backing panel, clear annodised etc.

The PCB would cost about $150 from pcbcart.com, cheaper from someone like iTead Studious, as little as $50.

The LCD screen would cost a bit, I don't have a price on the 3" model, but the 6" model is $200 from Mouser, so let's guess $150 that.

Other parts, let's say $50.

Battery from PowerStream.net come in thicknesses down to 0.5mm. But the 303040 model is 3mm thick 320mAh one costs $10.

Touch screen I don't know yet, haven't looked.

Time wise, a couple of days to select components and lay out the PCB, another day or two to design the case. You wait a month for the case prototype, but quicker if you knew someone with a suitable CNC machine. A day to assemble, and then another day to get a hello world running.

So really, apart from lead times, I estimate I could get a prototype working with 1 weeks worth of work, and under $700. That is fairly accurate because I've done the same thing before with the uWatch and uWatch projects, only difference is they didn't have the custom case.

The case I have shown is close to actual size of 45mm x 80mm x 5mm thick for the 3" display (not including backing plate). Actual thickness I'd need to tweak depending upon various available parts. The LCD itself is less than 1mm thick.

This isn't pie-in-the-sky stuff, those are real figures. The only unknown for me is how well someone like eMachineshop can machine such an aluminium case.

Dave.



Edited: 19 Sept 2011, 9:29 p.m.


#21

Wow. Thank you for all the detail! You got me very interested.

I'm taking this off-line and sent you email.

#22

I really hate to have to type on something without feedback (like my mobile phone).

Since I have to write plenty of emails, I often have to think while typing, carelessly touching one key and having a row of oooooooooooooooooooooooooo typed would be really annoying. Same with a calculator - I need to know if a keystroke has been registered or not.


#23

Quote:
I really hate to have to type on something without feedback (like my mobile phone.

Does that feedback have to be tactile? What about audible?

I have an iPad where I've installed i41CX+ from AL Software (very cool app, BTW). It offers several audible tones for keystrokes, which I find are quite acceptable for confirming data entry.

#24

There's no getting around tactile feedback, otherwise I would be satisfied with using the emulators on my phone alone. I've considered a system based on the iPhone/iPod Touch that would fit around the devices like a case. By using traditional keys and making sure the snap domes interact with the capacitive touchscreen you get the best of both worlds. However, it's still inconvenient.


#25

Quote:
I've considered a system based on the iPhone/iPod Touch that would fit around the devices like a case. By using traditional keys and making sure the snap domes interact with the capacitive touchscreen you get the best of both worlds. However, it's still inconvenient.

That's a clever idea. And for example the elastomeric "domes"
in the pioneer series are so close to voyager metal domes w/r/t
tactile feedback, I didn't realize they weren't until I had
need to do a repair. So carrying around a dome skin is feasible.
But regrettably it fails the "grab the box and calculate"
immediate gratification which likely most will find objectionable.

#26

That does sound vaguely cool. I'd like to see something like this. I'd fear it might be clunky and unwieldy in practice.

#27

Real HP calculators have physical buttons, period.


#28

Yes, understood.

It wouldn't be an HP. ;-)

Having no keys seems to side-steps the three biggest problems with pulling such a project off the ground, if I can believe the OpenRPN thread: case, keys, legends.

There's "no one size fits all" in calculators, most likely.

#29

I agree. In fact I still miss the mechanical keys of my old comptometer. Crunch, crunch!

Seriously though, has anyone who argues for capacitive screens ever tried to use one with gloves on or for that matter with any sort of keying reliability? Resistive screens at least work with gloves but have even worse registration reliability and of course, neither offers proper feedback.


#30

The grime and the paralax drive me away from touch screens. The grime (really just smears from skin oils) aren't bad if the display puts out its own light, but then we're back to something that consumes a lot of battery power. I want to be able to go many months without having to recharge or replace batteries.

#31

Thanks to everyone who responded!

Twasn't enough voices to draw a decisive conclusion, but it sounds like people really want keys.

My reality distortion field lets through Walter's "YMMV" as take-away.


#32

Tactile feedback of physical keys is essential for me.

I have an iPhone 15C app emulator called [SCI 15C] and it just isn't the same. It does offer sound click as feedback but that is annoying, thankfully you can turn the sound off for the emulator that I have.

Original 15C keys are better than 15C LE keys but the LE keys are very much welcome.

Edited: 20 Sept 2011, 7:53 p.m.


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