Author Topic: Muri ONE: Low Profile Wireless TKL  (Read 10762 times)

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Offline ice9js

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Muri ONE: Low Profile Wireless TKL
« on: Fri, 13 November 2020, 07:56:54 »
Hi everyone!

So for the past 6 months or so I've been working secretly on a little project of mine to possibly replace my old dinovo edge keyboard.
It looks to me like there's a pretty big void in high-end low profile keyboards which I'd maybe like to fill some day so I thought I'd maybe gather some feedback before committing to any design and getting the parts made - I'm trying to be economic.

Features I'm aiming for:

- Low profile: The current design is for a total thickness of 15mm with keycaps included. (11mm body only).
- All aluminum chassis
- Wireless: I've decided on Nordic's nRF52840 which supports Bluetooth 5.2 (and has a few other tricks up its sleeve as well :))
- USB-C for charging or wired use.
- Capacitive slider: I like the function of rotaries, not so much the look. Controlling volume for a start but I wonder if I can also make it work for doing stuff like controlling sliders inside software light Lightroom or DAWs - not a priority right now though.
- Macro row: Mostly to offset, the extra spacing around the slider on the other side.
- Top mounted plate/PCB: I was initially thinking of just milling out the holes from the top enclosure but now I'm a bit worried about the wireless reception - there isn't enough room inside the case for a proper slot antenna implementation and an external one isn't an option. So the plate would have to be non-metal.

The main questions I'm struggling with now are:

Choosing the appropriate switch system

So far I've been hoping to use Kailh's Choc (v1) switches with their biggest obvious drawback so far being the lack of keycaps. So my idea was to use these caps for the initial prototypes although they're not compatible with the Choc stabilizers - nor can I see any other stabilizers I'd be able to get that work with the switches.

An alternative would be to use their v2 Choc with cherry stems, though that'd probably still require custom molds in the end as I didn't see any with a profile lower than ~6-7mm (I'd really like to stay around ~4).

Choosing the right layout

I'm currently deciding between two layouts:

- A classic TKL
- Or a narrower variant

I'm personally a fan of the latter, having the page-up/down buttons closer and I can't remember the last time I used the arrow keys.
It'd also help on cutting down on the increased width from the slider/macro row (regular TKL case would be ~425mm wide, one row less gives ~406mm).
Curious what other people think.

I'd like to eventually make a matching numpad as well.

Where are things at currently

So I started by writing the firmware last spring. It's custom as ZMK wasn't a thing back then, but I'm still planning on open sourcing it once I'm done.
Core functionality is pretty much fully implemented. I've held off for stuff like LED animations etc. until I have a proper board to test with.

I have a ready PCB design - though obviously I'm holding off on ordering the boards before deciding on the layout. And I'm starting to have second thoughts about the Chocs :(
I'm wrapping up the design of the TKL case, but the more I think about it I think I'd like the narrower layout more.

Help me draw the line and I promise you some nice pictures next week :D
« Last Edit: Sun, 25 July 2021, 14:19:38 by ice9js »

Offline ice9js

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Re: Low Profile Wireless TKL Build
« Reply #1 on: Sun, 22 November 2020, 11:02:14 »
Standard TKL it is.
Unfortunately I made the mistake of using the default 19x19mm switch spacing and eventually I figured I should probably stick with 18x17 which seems to be the standard for Chocs, to better serve people already invested in them.
Besides, over the width of the entire layout, adjusting the spacing saves as much as removing an entire column with the normal spacing.

Anyway, I pretty much wrapped up the design on the case. It ended up being 12mm thick without keycaps, so the total height should be around 16-18mm.
The whole thing is still pretty large, so to keep it visually smaller I went with these 'winglets' on each end to isolate the macro keys/slider area with the added bonus of the keyboard to appear as if it's floating when looked at from the right angle.
Excuse my poor render quality - it must be like 15 years since I tried to render anything... For now I'm not really willing to spend much time on that, it's really just to give a decent overview of how things will look.

256361-0
256363-1
256365-2
256367-3
256369-4

Now, I'll have to update my PCB to match the new spacing and hopefully should be on my way to ordering a prototype soon after.

Offline ice9js

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Re: Low Profile Wireless TKL Build
« Reply #2 on: Tue, 22 December 2020, 22:34:37 »
It's been a while since the last update... and in the mean time I went through another three revisions of the PCB until it felt right.
Redoing it in 'choc spacing' was getting pretty hard while trying to avoid routing on the inner layers and when I finally managed it, I decided just don't like the look of the rectangular keycaps.

Anyway, this is it:

258408-0
258406-1

Even though it's only my first PCB, having redone it four times allowed me to notice and address a bunch of thing I definitely wouldn't have noticed in my first run.
Yet, perhaps the most important lesson would be to remember this is a prototype and to keep my options open.

And so I've added breakaway tabs for the macro column as well isolated it electrically from the other components, as I will be ordering a few of these anyway and I might want to use one for a different project where that part would be obsolete.
I have two sets of stabilizer holes under the spacebar, one to accommodate for the stock 'awkwardly-sized' Kailh stabilizer that's actually obtainable and the other using the standard 100mm 6.25u spacing for me to experiment with.
The board is using hot-swap sockets which I believe will make working with it much easier/faster for prototyping purposes. While that somewhat restricts the layout options (this one is ANSI) I've made sure my key/rgb matrix can accommodate the additional ISO key if that were to be a possibility.

Unfortunately some things can't be made adjustable :( I'd love to test different positions of the BLE module relative to the case for optimal performance but that can't really be done without manufacturing several PCBs and having some more advanced RF knowledge. So I'm making a bet that it'll work best under the spacebar considering the rest of the case is metal. If it doesn't, I'll see what I can come up with then.

As for the general specs:
- The board is powered by the PAN1780 BLE module (nRF52840, ZMK compatible although ZMK doesn't offer support for any of the additional features just yet, I think).
- Per key RGB provided by two IS31FL3743A chips. The led's are actually mounted on the opposite side of the board as assembly costs aren't actually that much higher, the led's themselves are much cheaper than the larger reverse-mount ones and it frees up TONS of space on the board.
- There's a dedicated CY8CMBR3106S touch controller to take care of the slider which will be on a separate FPC so it can be mounted correctly inside the case.
- ESD protection.

So, hopefully I'll have the thing assembled for the next update and with the basic keyboard functionality working. Then it's time to implement rgb matrix and touch slider support.

PS. To all of you that have been doing it for a while - respect. I must admit it looks way easier than it is. I expected the PCB layout to be a cakewalk considering the PCB size but with all the holes and the staggered layout... It's a nightmare to work with.

Offline King Icewind

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Re: Low Profile Wireless TKL Build
« Reply #3 on: Thu, 24 December 2020, 10:22:56 »
Nice work on your project! Why did you choose the IS31FL3743A over the IS31FL3733? Is this a four layer board? Looking at your vias and traces, I donít think it is. Iíd definitely recommend changing it to a four layer board of it isnít. It will help your trace paths a lot.

Offline ice9js

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Re: Low Profile Wireless TKL Build
« Reply #4 on: Fri, 25 December 2020, 04:23:08 »
Nice work on your project! Why did you choose the IS31FL3743A over the IS31FL3733? Is this a four layer board? Looking at your vias and traces, I donít think it is. Iíd definitely recommend changing it to a four layer board of it isnít. It will help your trace paths a lot.

Thanks! So to answer that:

IS31FL3733 seems to be going out of production and I believe the IS31FL3743 is the recommended replacement for new designs. Other than that, key differences would be it's using a higher scanning frequency which probably is only significant for the largest of these drivers, it allows for configurable matrix size and promises reduced EMI which is nice I guess.

It is in fact a four layer board except all signal/matrix traces are routed on the outside layers. The inner layers... one is solid ground and the other is ground as well as my VBUS and +3.3V power rails. From what I've read it's best not to break up the ground/reference planes with traces too much if you can avoid it hence all signal traces are routed on the outside.
I understand these are all relatively low speed traces other than maybe the USB differential pair so it may matter less but I decided not to take too chances with it as who knows, I might want to get it certified depending on where get it to.

Offline ice9js

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Re: Low Profile Wireless TKL Build
« Reply #5 on: Sat, 30 January 2021, 13:06:01 »
It's been a while so I thought I'd post another update. A lot has been going on lately.

First of all, PCB prototypes arrived and they look pretty great, it's awesome to finally be able to hold the product of my work:

260877-0260879-1260881-2260883-3260885-4

Unfortunately, not assembled yet. The required mid-mount USB-C connector went out of stock seemingly everywhere so I'll only be getting them together with some remaining parts next week.
That said, I'm already very happy with the choc stabilizer holes coming out just right - I didn't have the actual stabilizers on hand yet and had to rely on some unofficial measurements I found online.
Then starts the challenge of actually implementing the remaining features. Speaking of which...

I have made the decision to embrace ZMK for this project. Generally, what scares me most about using open source projects is the politics, specifically when you as the user might have different short-term priorities than the project. I've been following them for a while and besides being a bunch of very nice people, their modular approach totally mitigates this risk of a diverging feature set, and actually would allow any third-party to draw from both ZMK core as well as your custom features should you go that route.

Finally, I have finalized the case design and will be ordering 3d prints for it soon. While I had the general design mostly figured out, it took a while to figure out the right hole placements and generally optimize it for CNC machining.
I also started working on actual keycaps, which would fit 19x19mm 1U spacing, rather than Kailh's 18x17mm thing. I played around with both a basic spherical and cylindrical designs, but ultimately ended up going for a hybrid of the two which I think should look the most pleasing of the three (especially with legends on it) and hopefully also feels good. I'll only be able to tell once I print them too.

260887-5260889-6260891-7

Here's the three different profiles I made for comparison (top to bottom: spherical, combo, cylindrical):

260893-8

So, what are the next steps?
For the near future, obviously getting the board assembled and flashing ZMK onto it.
That said, I'm probably also going to spend some time on some decent quality renders to get an interest check going as soon as I get the case prints and have validated the design.

Offline ice9js

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Re: Low Profile Wireless TKL Build
« Reply #6 on: Thu, 20 May 2021, 15:17:45 »
Failure...

...is the word. I really got ahead of myself there with that hint at getting an IC going.
But although the recent months have been a bit of a struggle, I've not given up on my project just yet and there's light at the end of the tunnel. So... what happened?

The case

Due to my lack of experience, it was very hard to find anyone willing to take on the project and when I did, the result was not what I had hoped for. The finish was so-so, the parts didn't actually fit together, nor did the PCB.
As I later found out, the core issue seems to be the sheer size of the part as well as relatively very little surface area on both top and bottom. Fine details and small tolerances didn't help either.

For my next prototype I will be looking at machining one myself from either wood or aluminium if it doesn't come out much more expensive. If I do go the 3d-printing route again, I'll split the model into multiple parts that can be glued together and most-likely do away with some features or details that are not necessary for functional validation of the design.

Speaking of functional validation, even though it came out the way it did, it was money well spent. Although I'm not able to assemble the whole thing using the parts I have, I was still able to get a feel for it and the verdict is:

- I'm really happy with how thin the case is (MX keys for comparison) and it feels almost exactly as good as I would've hoped for...
- ...'Almost' because the wrist-pad is way too narrow, it needs to be pushed out another 1.5-2cm so your fingers rest on the home row in the natural position.

268840-0268842-1268844-2

PCB

For my first PCB I consider it a success. That said, it wasn't without it's own fair share of issues:

- Assembling the entire thing by hand was an absolute nightmare (ca. 450 smd parts) and as I later found out, I burned about 90% of the LEDs in the process.
- By mistake I used a 3.3V ESD diode for VBUS which led to me removing all the QFP chips and the bluetooth module looking for shorts. Putting them back evenly afterwards was a challenge.
- I also removed the USB port as part of that process and shorted one of it's D+/D- pins which caused data not to work.
- One of the debug output footprints I used (from official KiCAD library) was mirrored rendering it useless. Luckily I was precautious enough to add a second, different one just in case which worked just fine.

268846-3268848-4

After working through all that, I did get ZMK flashed onto the board and validated what I could, even wrote a driver for the IS31FL3743A RGB matrix controller.
But once I decided I learned what there was to learn from this board, I switched my attention to designing the next version - adding features, simplifying the design and making it easier and cheaper to manufacture.
The new boards are already being manufactured and I'm hoping to be able to start working with them by the end of the month - and this time I checked the assembly option ;)

To point out some key changes:

- Added a battery fuel gauge for accurate battery level as well as temperature measurements.
- Added a 5-LED strip indicator above the navigation cluster for all your indication needs (bootloader, charging, caps lock or just pretty lights if you fancy).
- Backtracked on my idea of using two IS31FL3743A drivers and replaced them with a single IS31FL3741.
- Added a buzzer...
- ...and soft-shutdown capability for the power switch so your board can properly greet you when you turn it on or off.

268854-5268856-6

Keycaps

I also finalized the keycap profiles - unfortunately the availability of full-size Choc compatible caps hasn't improved much in the last year - and will be printing them next week for some initial testing.

268850-7268852-8

Offline King Icewind

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Re: Orion 92/93: Low Profile Wireless TKL
« Reply #7 on: Fri, 21 May 2021, 09:29:27 »
Great work on your project! What are you using for a fuel gauge?

Offline ice9js

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Re: Orion 92/93: Low Profile Wireless TKL
« Reply #8 on: Fri, 21 May 2021, 13:08:26 »
>Great work on your project! What are you using for a fuel gauge?

Thanks!
I'm using MAX17055 for the fuel gauge. There's a ready Zephyr driver for it and I believe some people have already successfully used it on their ZMK boards as well. I think it has best-in-class current consumption as well which is a nice bonus.

Offline ice9js

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Re: Orion 92/93: Low Profile Wireless TKL
« Reply #9 on: Sun, 23 May 2021, 14:25:18 »
This weekend I decided to update the case to fix the wrist pad but I feel like the more I think about it the less excited I am by the design.
The wings make it very complex yet the effect isn't really felt that much because the keyboard is already so low profile.

So feeling somewhat inspired by the refreshing new iMac series I decided to draft up a quick new design for the case that's still compatible with my current PCB:

269007-0269009-1269011-2269013-3269015-4

I removed the 'wings' and I went for a horizontal accent piece instead of two vertical ones.
Having just the angled part of the wrist pad be a different color helps keep things interesting instead of having just a big slab of metal - even though it's 2cm wider now. It's also narrower by about 18mm.
I'm thinking I could maybe even try engraving some sort of a low key pattern on it to make it even cooler. We'll see.

I'm feeling pretty pleased with the updated look and will continue working on it. What do you think?

Offline aabbcc

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Re: Orion 92/93: Low Profile Wireless TKL
« Reply #10 on: Tue, 25 May 2021, 17:32:27 »
This looks amazing! I'd 100% buy one if it didn't have the wrist pad (which also seems a bit uncecesary since it so low profile, it also adds unecesery depth to an otherwise beauitfully designed keyboard imo).

You don't have any plans on making a full size version?

Offline zungzangbi

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Re: Orion 92/93: Low Profile Wireless TKL
« Reply #11 on: Tue, 25 May 2021, 20:15:43 »
I found this project to be strikingly creative. Please keep up the good work!

Offline ice9js

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Re: Orion 92/93: Low Profile Wireless TKL
« Reply #12 on: Wed, 26 May 2021, 02:05:50 »
I appreciate the kind words, thank you!

I'd 100% buy one if it didn't have the wrist pad

I realize it might not be everyone's preference although for me, personally, it definitely makes a very noticeable difference. Apart from the typing position, because it's a large piece of metal it also helps keep my hands from sweating for longer - very desirable feature for myself. As an added bonus, it also makes it pleasant to use on your lap.
But yes, so with the updated design, there's a number of new opportunities - the battery fits in the area under the slider now so technically it's possible to get rid of the wrist pad.
Now I'm wondering whether it should be removable or just an entirely separate version without it. If I make it removable, it's probably better for user experience as you get to decide and reduces the unique part count but then I either end up with very sharp corners on the bottom or I have to sacrifice the 'seamless' transition.
For now all I can say the idea is in the back of my head and I'm giving it time - but I'm open to a compromise here.

You don't have any plans on making a full size version?

No. But I'll hopefully do you one better: how does a wireless numpad sound?
It'd feature the same design that I end up with, possibly a screen in place of the top row and a slider as well (need some space for the battery and besides, would make for a very nice media pad).
You could connect it to the 'main' keyboard so it acts as a split, or to your computer directly if you prefer, but that it would also have some basic standalone functions like a calculator etc.
By being detachable you can place it wherever it suits you most or get it out of the way completely - and obviously if you don't want it you don't buy it.

That's the idea. I'm still at an early stage and the keycaps are the biggest question mark at the moment, followed up by getting the case manufactured. Once I've solved these two problems I'll probably be able to say more on how viable it is for me to do the numpad immediately or if it'd need to be a follow up project and how that'd work then.

Offline azhdar

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Re: Orion 92/93: Low Profile Wireless TKL
« Reply #13 on: Wed, 26 May 2021, 03:56:25 »
Orion is a name that is already known in custom keyboards:
Exemple : https://geekhack.org/index.php?topic=109033.0
The maker is Duck, a Korean designer, he has already made a few versions of the Orion.

If you don't want to rub anyone the wrong way, you should reconsider the name.

Offline ice9js

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Re: Orion 92/93: Low Profile Wireless TKL
« Reply #14 on: Wed, 26 May 2021, 05:23:24 »
If you don't want to rub anyone the wrong way...

Not if I can help it, no. Thank you for pointing it out, I was initially using it as a codename and I wasn't aware it was a thing already so I just updated the title.
Sorry for any confusion - I'll try to come up with a new name soon.

Offline suicidal_orange

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Re: [Name TBD]: Low Profile Wireless TKL
« Reply #15 on: Wed, 26 May 2021, 10:51:27 »
While not for me this is a very impressive project - good to see it progressing :)
120/100g linear Zealio R1  
GMK Hyperfuse
'Split everything' perfection  
MX Clear
SA Hack'd by Geeks     
EasyAVR mod

Offline aabbcc

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Re: Orion 92/93: Low Profile Wireless TKL
« Reply #16 on: Wed, 26 May 2021, 16:34:33 »
I appreciate the kind words, thank you!

I'd 100% buy one if it didn't have the wrist pad

I realize it might not be everyone's preference although for me, personally, it definitely makes a very noticeable difference. Apart from the typing position, because it's a large piece of metal it also helps keep my hands from sweating for longer - very desirable feature for myself. As an added bonus, it also makes it pleasant to use on your lap.
But yes, so with the updated design, there's a number of new opportunities - the battery fits in the area under the slider now so technically it's possible to get rid of the wrist pad.
Now I'm wondering whether it should be removable or just an entirely separate version without it. If I make it removable, it's probably better for user experience as you get to decide and reduces the unique part count but then I either end up with very sharp corners on the bottom or I have to sacrifice the 'seamless' transition.
For now all I can say the idea is in the back of my head and I'm giving it time - but I'm open to a compromise here.

You don't have any plans on making a full size version?

No. But I'll hopefully do you one better: how does a wireless numpad sound?
It'd feature the same design that I end up with, possibly a screen in place of the top row and a slider as well (need some space for the battery and besides, would make for a very nice media pad).
You could connect it to the 'main' keyboard so it acts as a split, or to your computer directly if you prefer, but that it would also have some basic standalone functions like a calculator etc.
By being detachable you can place it wherever it suits you most or get it out of the way completely - and obviously if you don't want it you don't buy it.

That's the idea. I'm still at an early stage and the keycaps are the biggest question mark at the moment, followed up by getting the case manufactured. Once I've solved these two problems I'll probably be able to say more on how viable it is for me to do the numpad immediately or if it'd need to be a follow up project and how that'd work then.

Wireless numpad sounds even better, keep up the good work! Does the bluetooth chip support multi device pairing?

Let me know if you need help beta testing, you could just send over a pcb and I'll order the bom, I repair and build diy synthesizers in my spare time so I know my way around electronics :)
« Last Edit: Wed, 26 May 2021, 16:43:18 by aabbcc »

Offline ice9js

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Re: [Name TBD]: Low Profile Wireless TKL
« Reply #17 on: Wed, 26 May 2021, 18:26:38 »
Thanks y'all. It's really motivating to see some action in the thread. It's much appreciated.

So today I finally got around to printing the first batch of keycap prototypes. It's only my first print ever so bare with me...

269237-0269239-1269241-2

As you can see, the 'front' edges of the keycaps are a little out of shape. Spacebar to an extreme degree. This was my mistake trusting the slicing software with generating supports.
Unfortunately the generated ones weren't enough to firmly hold onto that first edge from which the print is started. I'll make sure to add plenty extra for the next batch.

Other than that - I'm quite pleased. Even without sanding down the support residue the fit is near perfect and all the mounting points match up as well.
They came out quite a bit flatter than I expected, but that's something I found very hard to judge on a screen. You can still feel the sculpt but I'm not quite satisfied just yet.
I'll probably experiment a bit more with narrowing down the radius without making them too thin in the center.

It'll be a little while before I do the next revision as I need to get myself some resin first (first round was on the house).

Let me know if you need help beta testing, you could just send over a pcb and I'll order the bom, I repair and build diy synthesizers in my spare time so I know my way around electronics :)

Nice, thanks! I might just take you up on that some time if you want to play with it. It's not like I've got something to do with all the extras.

Offline ice9js

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Re: [Name TBD]: Low Profile Wireless TKL
« Reply #18 on: Sat, 05 June 2021, 14:59:35 »
Time for another update  :)

I did some more testing on the keycaps and I managed to find some areas for improvement:

- The profile might just be too shallow, I'll need to experiment with using a smaller radius.
- I assumed the stabilizer connectors are symmetric but it turns out the 'cross' on Choc stabs is actually slightly larger on one axis. My dimensions are based on the shorter axis. I can force them on but I can feel it's not the way it should be. I'll need to fix this.
- Theoretically only 2u and above need stabilizer but the 1.75 feels really wobbly actually - to the point where I don't like it. I'll probably just try to add a set of stab connectors on there too and experiment some more. Could also be down to the quality of my initial prints.

I took some time to parametrize my model (Grasshopper is magic!) so I'm easily able to control the shape and other aspects of the keycap and auto-generate the entire family. This should speed up the iteration time a lot.

On another note, new partially-assembled PCBs have arrived and seem to live up to the expectations. Just need to throw on the ICs on there and I can get back to the firmware side of things.
I also went ahead and got a batch of slider FPCs - pretty excited to test them too.

269978-0269980-1269982-2

Offline ice9js

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Re: [Name TBD]: Low Profile Wireless TKL
« Reply #19 on: Thu, 17 June 2021, 12:12:52 »
Another round of keycap protos  :) As you can see the shape is a little bit different now as well with the scoop centered on the stem where previously it was offset to the top.

I decreased the radius on the surface by about 30-35% and it does feel quite satisfying now, interestingly especially so on modifiers. The stabilizer connectors also fit perfectly now.
Unfortunately this round is quite a bit more prone to breaking - I'm not sure if it's down to it not being completely cured or the resin itself, I'll experiment some more. But they did a great job as non-functional prototypes and I'm very satisfied with this new direction. That said, I'll probably do a few more runs using some 'extreme' settings just to make sure I actually have all bases covered before committing to one design.

270792-0

Other than that, I've soldered on the missing chips on one of the PCBs and will be going back to doing more software work for ZMK.

One question I have... is there any tricks to make reworking PCBs easier? I don't know what kind of solder they used there but it was close to impossible to reflow using hot air and even trying to remove it with a wick and an iron proved to be quite difficult as well (I use plenty of flux). Once I applied fresh solder to the pads, it was smooth sailing from there.

Offline aabbcc

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Re: [Name TBD]: Low Profile Wireless TKL
« Reply #20 on: Mon, 28 June 2021, 03:46:40 »
Another round of keycap protos  :) As you can see the shape is a little bit different now as well with the scoop centered on the stem where previously it was offset to the top.

I decreased the radius on the surface by about 30-35% and it does feel quite satisfying now, interestingly especially so on modifiers. The stabilizer connectors also fit perfectly now.
Unfortunately this round is quite a bit more prone to breaking - I'm not sure if it's down to it not being completely cured or the resin itself, I'll experiment some more. But they did a great job as non-functional prototypes and I'm very satisfied with this new direction. That said, I'll probably do a few more runs using some 'extreme' settings just to make sure I actually have all bases covered before committing to one design.

(Attachment Link)

Other than that, I've soldered on the missing chips on one of the PCBs and will be going back to doing more software work for ZMK.

One question I have... is there any tricks to make reworking PCBs easier? I don't know what kind of solder they used there but it was close to impossible to reflow using hot air and even trying to remove it with a wick and an iron proved to be quite difficult as well (I use plenty of flux). Once I applied fresh solder to the pads, it was smooth sailing from there.

Caps look awesome!

As for reworking pcb. If you ordered a pcb with presoldered componentes they most likely use lead free solder which can be a bit trickier to desolder. Easiest way to desolder in this case is to add some flux and a small amount leaded solder i.e. Sn60/Pb40 or Sn63Pb37 on top of the soldered joint, this will make it much easier to then desolder or reflow.

Offline Minahctrl

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Re: [Name TBD]: Low Profile Wireless TKL
« Reply #21 on: Tue, 29 June 2021, 14:17:20 »
following. really liking this so far canít wait to see the outcome

Offline ice9js

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Re: [Muri ONE]: Low Profile Wireless TKL
« Reply #22 on: Sun, 25 July 2021, 14:16:37 »
It's been a while but I've been busy.

First things first, new brand name: Muri (pronounced [muri]).
Sounds good enough to me, and haven't seen it used yet for any keyboards or peripherals so that should solve that issue.

I implemented a ZMK driver for IS31FL3741 and I'm currently busy working on adding more advanced illumination support as well: splitting the rgb matrix into independent areas, per-key rgb etc.
The idea is that it should be possible to drive every single LED with one or two driver ICs saving GPIOs on the main MCU as well as maximizing customizability as nothing is ever hardwired for a specific purpose, rather configured in the software.
While that is still some time away, here's the mandatory christmas show:

* video0.mov (1582.7 kB - downloaded 54 times.)

It's just a single underglow animation, although it's worth noting IS31FL3741 is now a viable ZMK alternative to ws2812b where you quickly run into power issues.
As for the rows not lighting up, I need to touch up a few pins with some more solder, eventually... not a priority as it's not a blocker for other work.

Other than that, I've finalized the design for the case. Not much has changed on the outside, but there was a whole 'inside' I had to redo as well. I thought I'd share a few more details.
The decision has been made and the wrist pad is here to stay. The rationale being:

- I know for a fact it improves comfort, both on and off the desk.
- It can serve a decorative purpose as well. Being a fairly easy part to manufacture, it's possible to experiment with different materials and finishes based on personal taste.
- Although the keyboard has a fairly large footprint, the space on the inside is very limited due to the super low profile (12mm for the entire case) and the undercut around the sides. Having the little bit of extra room in the XY plane does make it easier to make the whole thing more structurally sound and fit a respectably sized battery.

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Since the new design doesn't have wings, I had to make a cavity and a holder for the slider for it to be able to detect touch 'through' metal. The sizing came out pretty convenient making it possible for it to double as a battery holder as well - the slider goes 'underneath' and the battery would be taped on top.
I've got some extra vertical space in there as well compared to the location on the old case, so I could potentially increase the battery capacity as well - currently at 1600mAh.
As the third and hopefully final revision of the PCB will feature fast charging, a larger battery is certainly an option.

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I will be attempting another 3D print of the case some time this week - this time by myself and in resin. Due to it's size, I had to split the thing into smaller parts which I'll be then glueing together. It looks something like that:

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I'll let you all know how that goes.
« Last Edit: Sun, 25 July 2021, 14:19:16 by ice9js »

Offline ice9js

  • Thread Starter
  • Posts: 24
Re: [Name TBD]: Low Profile Wireless TKL
« Reply #23 on: Sun, 25 July 2021, 14:37:34 »
As for reworking pcb. If you ordered a pcb with presoldered componentes they most likely use lead free solder which can be a bit trickier to desolder. Easiest way to desolder in this case is to add some flux and a small amount leaded solder i.e. Sn60/Pb40 or Sn63Pb37 on top of the soldered joint, this will make it much easier to then desolder or reflow.

Thanks for the tip! While I didn't have much luck with abundant flux on its own, adding a little extra fresh solder to the pads before doing anything else worked like a charm.

Offline ice9js

  • Thread Starter
  • Posts: 24
Re: Muri ONE: Low Profile Wireless TKL
« Reply #24 on: Sun, 01 August 2021, 10:27:23 »
The print came out so-so, with 3 parts not printing at all, other two coming out a bit crooked but nothing a bit of sandpaper can't fix.
Luckily, the bulk of the chassis came out near perfect so I could validate the fit and comfort of everything.

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Not sure if I will be 3d-printing another case prototype - I feel like if anything, the next step will probably be CNC.

A bonus of printing the case in parts is you can get cool cross-section shots.
It seems I also measured the USB cutout correctly - they way it's designed the actual port sits behind 1.5mm of case rather than stick through it for a cleaner look. Kind of like what you get on a MacBook.

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