clockworkpi

Will it be possible to use an E-Ink screen?

I have been watching this project and am thinking about pre-ordering, although I am thinking about waiting until I can see a review of the finished product.

The main question I have is, is there any way to replace the screen with an e-ink screen? I would love to have an e-ink version. I mostly want to use this in the evenings as a way to do some things without keeping myself too awake.

A normal eInk screen like in an eReader? I doubt it.
There is no official and easy to find documentation about them, you have to pay big money, the screen are quite pricey, and I’m not aware of an eInk screen with the screen ratio of the DevTerm.

They are not driven like a normal LCD pannel, and need a dedicated controller (and socftware) It is not that easy as just swapping the screen.

Now there are some SPI screen that do exist and are publicly documented (or at least par of) but they have at least one big issue. They are really slow, and even worse the one with colour. It can take up to 10-20s for full refresh on the coloured one. Also I’m not aware of any SPI one that would fit the DevTerm screen ratio.

And for both, the panel are not cheap. Back in the day a 6" panel for an eReader was costing something like $40 to $60, and I genuinely doubt the price went down (unless you are called Amazon)

So yeah. In theory it is possible, in practice I doubt it will happen

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Yeah, my question was for a kindle-like screen. I would totally pay some hundreds of dollars for such a panel, as my main goal is to have a device that is easier on the eyes and will not upset melatonin cycle by using it late in the day. But I may try something else, like jailbreaking my kindle and/or an external monitor instead.

Thank you for your response! Glad to know it is possible but unlikely.

That would be an interesting project though, but maybe, should be a different product than the DevTerm.

At least because the screen is not in the right shape.
It could be possible considering the modularity of the DevTerm to develop something around some of the parts.

This goes back a bit, but remember the “Yota Phone” with the e-ink back?
Not sure what point that would have in the long run. Ha maybe a keyboard with e ink panels that can contextually change their type face.
Having an e ink screen on the back would be kind of useless.
Perhaps a module that goes in place of the heat printer that has the same resolution as the printer, for a simple preview of what the printout will look like. Or a small playing card sized device that you can load whatever e ink image you want from the dev term onto.

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Not quite the same but the Freewrite is a keyboard + eInk screen, but it’s aimed at writing. I’m not sure if general purpose computing is possible, or if that’s what you want to do. It’s a good thing that you are willing to pay hundreds of dollars because that’s what it costs.

Compared to the DevTerm:
Pros - eInk screen, real scissor switch keyboard instead of a rubber membrane, 4 week battery life.
Cons - Almost $200 more, more of a unitasking machine focused on writing. Does not seem hackable

$500 you mean?

because 200 is about half the price of that device.

It is honestly way too expensive for what it is, and I have the feeling the keyboard is small too.And full size or not, the screen is way to small to do any proper work.

At least the DevTerm use more of it’s own real estate on that side.

Also “scisor” does nto mean mecanical, they still have rubber some under such keycaps. It is just the way the key travel up/down which is different.

And the battery like I would like to see that if you type frequently. Not sure is would last that long

No I mean “almost $200 more” because it’s less than $200 more.
Freewrite Traveler that I linked above - DevTerm with either of the cheapest compute modules:
$429 - $249 = $180 => “almost $200 more” which is a closer approximation.

You said mechanical, not me. I said scissor. Freewrite Travelr has a scissor switch keyboard like a typical laptop. DevTerm does not claim scissor. Looking at the DevTerm exploded view the keys appear to be a single rubber membrane sandwiched between the white outer shell and the yellow inner frame. I could be wrong on that, but I can’t find any claims either way about what the keys / travel are like on the DevTerm. There is another Freewrite model which I did not link to with a real mechanical keyboard with cherry switches.

You complain about the traveler keyboard size. What I can find is that the DevTerm keyboard is 190 mm wide vs the “full size” keyboard on the Freewrite Traveler (which they don’t specify, but another review says the Traveler is 300 mm wide and the keyboard is probably similar to that on my apple laptop I measure to be 275 mm). My point is if you think the Traveler keyboard is too small then the DevTerm is going to be WAY too small. Likewise if you are throwing shade at the Freewrite battery life what are you expecting from the DevTerm? My guess is a few hours on 2x18650 batteries.

Look I’m not ordering a Freewrite here and I’m still on the fence with DevTerm. I think the DevTerm is borderline too expensive and the Freewrite is definitely too expensive. Freewrite is focused on hacking and looks like it’s going to have a pretty mediocre typing experience while Freewrite is focused on writers and a good writing experience and doesn’t look as hackable. Maybe it’s expensive because of the e-Ink display? OP asked about an e-Ink screen and I’ve wanted something like that too and the Freewrite is the closest I’ve found.

Oh, looks like that one is on special, down from the original $599; which while crossed out kind of looks like $500. Possibly where that confusion lies.

Devterm could use butteryfly action keys. We just don’t know.


There has been a lot of discussion re: mechanical keys from others, so definitely something on people minds.

Re: keyboard size, I think there has been some misinterpretation on meaning.

Implying that this keyboard is “also” small; not “too small”

Likewise with the statement re: battery life,

I’m not sure if it was shade being thrown per se, or rather a comment re: the reported 4 weeks of battery life; almost too good to be true if someone was to use it regularly.

There aren’t any sides here. Just a bit of confusion with the interpretations of one another’s meaning. I’m detecting a fair bit of defensive language here, so just thought I’d clarify the necessity for it. :slight_smile:

Oh fair (for the price) that’s not how I understood it :slight_smile:

Yes you didn’t say mechanical, I know, but scissors or not, they are still rubber dome contact.
The scissor are just the way the keycap is hold and allow it to move up/down, and have nothing to do with how the key contact is done and this type of mechanism only really exist for devices that need to fold and have a low profile keyboard like for a laptop, both thing that the DevTerm do not need.

The way the keyboard of the DevTerm is made is more close to a desktop keyboard than a laptop keyboard.

And I did not complain, I just said that the “traveler” keyboard feel too small to be called a “full size keyboard”,

I’ve more complained about how their device is priced and how small the screen on it is.

I do know quite well how an e-Ink screen work, and I do have doubt about the announced autonomy, especially if you type a lot.
The autonomy they announced is actually more than double than most eBook reader were you update the screen every couple of minutes, not multiple time per seconds as when you do type.

As for the DevTerm, I probably have missed it, but I don’t remember CPi announcing any autonomy time. I would personally expect something like 2 - 4 hours of continuous use time, maybe a bit more depends on how the software and the hardware is optimised, and of course what you are doing with it.

As for an e-Ink screen, they do consume as much, if not more current than a normal LCD screen with backlight when they do refresh, and that’s whatever the size of what is refreshed on screen, yes they consume nothing when they are not refreshed

And considering the e-Ink screen size they seems to use, there is for about $60-70 in low volume of screen in there.

And thanks @javelinface

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