[IC] BLE capsense controller (Topre & *springs)

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DMA

06 Aug 2018, 04:51

So I finished a draft PCB for CommonSense BLE.

This one it doesn't come in proto kit form you can buy elsewhere, because I want a decent battery life. And a "decent battery life" (read "more than a day from 500mAh Li-ion battery) means using buck converters instead of LDOs.
The BOM runs close to $50 (~$10 CS MCU, ~$15 BLE module, ~$10 battery, ~$10 power controller plus small parts). Plus PCBA, plus shipping - around $70.

Is there any interest at this price?

I'm also not sure if BLE is a limitation as opposed to BT. Yes, old windows machines won't work. Macbooks from 2011 works, iphone4 works, samsung galaxy S2 works. Those are pretty old hardwares..

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Muirium
µ

06 Aug 2018, 12:44

I’m definitely intrigued. Bluetooth is huge for me. And yes, BLE is fine. Vintage computing is not what I’m aiming for here. Usb is adequate for all that.

Now, Beamsprings and Model Fs largely come in metal cases. Bad for signal strength and the portability Bluetooth plays into. The AT is a nice exception, but still a great big weighty beast. I’d like mine in Bluetooth, sure, but it’s not first in line.

Topre is where the appeal really lies. And Topre has its own challenge. With the notable exception of the HHKB (already nicely adapted by Hasu and even available from Topre themselves now in Bluetooth), Topres have integrated controllers. Here’s the particularly wee one on the NovaTouch:

Image

The NovaTouch is a board I’d love to controller swap. (Those bloody stupid auto fire keys!) The case has a conveniently wired USB micro socket to purpose for charging, and there’s just enough space in there as I recall for a battery and smallish controller. The trouble is accessing the matrix, I presume?

The Realforce is the board I’d love most of all to Bluetooth. I only have one of those though, and I prize it more than the NovaTouch. The price you’re talking is fine by me for these Topre boards. It’s the installing that I fear.

User avatar
hansichen

06 Aug 2018, 13:25

This controller here is meant to replace the original one, as the novatouch has the controller on the pcb you would have to cut traces between the capsense pads and the controller and implement the new controller there. It is possible but not a very appealing work.

As you've already seen DMA made a good post about Realforce boards here: workshop-f7/topsense-better-capsense-no ... 19550.html These boards are way easier to convert so I'd rather use a tkl realforce than a novatouch.

It's really nice to see all the progress with DMA's controller. I personally don't see myself needing one right now but we should definetly think about another nomination for #dta8 at the end of the year. :)

User avatar
Muirium
µ

06 Aug 2018, 14:01

See that’s the thing. I’m thick and need this explained to me. Did he chop anything off the original keyboard?

If this controller can route *around* existing controllers, consider me impressed. I’d be loathe to knacker my Realforce though. Because if anyone can well and truly fuck up a mod, I’m your man.

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hansichen

06 Aug 2018, 15:03

I think the controller of a realforce is on a seperate pcb (though I don't know how it is connected to the PCB, some topre guy will be able to tell more about it). So the main realforce pcb is just a passive pcb and all components are on a different board. This controller then works like an xwhatsit but instead of pushing the controller onto the pins you have to solder that thing.

With a novatouch you have to "disassemble" the current controller first. Generally it's working the same way as the realforce but you just have everything on one instead of two pcbs. So you still have the matrix which is connected to the controller itself. This goes through traces on the pcb. When you want to replace this controller you first have to make sure to seperate the matrix from the controller, that involves cutting all the traces on the pcb. They you have to open the protective layer of the trace on the matrix side so that you can solder a cable onto it, that one connects to the new controller. With that technique you'll be able to replace the controller.
As this is rather complicated and an annoying work I wouldn't want to do that myself. If you really think about doing that you should probably get some testing material first. As many people reuse the novatouch stems for their hhkbs or realforce boards you may be able to find some cheap or free pcbs to get some experience.

User avatar
Laser
emacs -nw

06 Aug 2018, 15:42

Ideally, for the Novatouch one would write an alternative firmware for the current controller, with information gathered from here most probably: https://github.com/vekkt0r/novatools (it is already possible to change the key layout in a basic way). And the author's blog (two parts: one and two).
Of course if you check the issues you'll see me there too :P
Last edited by Laser on 06 Aug 2018, 16:43, edited 1 time in total.

User avatar
DMA

06 Aug 2018, 16:33

Muirium do you have a whole board picture of the novatouch? Although with novatouch probably whole board swap is in order. I've heard fullsize board PCB is about $30 nowadays.

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pyrelink

06 Aug 2018, 18:03

Sorry if all of this is answered elsewhere (I have not been following much here these days) but do you have any reasonable expectations for battery life say powering a HHKB? I have wanted to make my HHKB BT for a while now but the existing options battery life is kind of pitiful. If battery life with this controller is significant, I would definitely consider at that price point for my HHKB.

User avatar
Muirium
µ

06 Aug 2018, 19:01

Hey Pyrelink! A long critic of Hasu’s HHKB BT controller, I finally snapped and just bought the damn thing last autumn. My stock HHKB Type-S was drawing my laptop’s battery too quickly for my liking so I reckoned why not. I threw the biggest battery I could find at it: 2500 mAh (about the same capacity as this iPhone Plus) and I must say I’m absolutely delighted. The HHKB is so much better with Bluetooth. Works with my iPad at last (transforming it into a stellar writing machine with Scrivener) and gives me hours back on my Mac as well. Keyboard battery lifetime? I’m yet to drain it. Charging every 2nd or 3rd night of active use (way less than the iPad) it’s never broken a sweat. Never even seen the low battery light.

In short: while theoretically non-ideal, Prof. Hasu’s work is bloody spectacular in practice. My HHKB is worth twice as much to me now with his controller. Highly, highly recommended!

@Laser: thanks for the link. I hadn’t heard of that. The NovaTouch’s layout is pretty decent, besides that one lousy key. I’ve always imagined repurposing it for Bluetooth pairing control! Something beyond that project’s reach, of course. As is, the function key is useless to me, but also never pressed, so it’s no pressing problem.

@DMA: I’ll open one up and take a picture for you. Mine are both TKL (which I believe is all there ever was), one is ANSI and the other ISO (and a prototype no less). What are you suggesting re: a whole new PCB? Experiment on a spare?

User avatar
pyrelink

06 Aug 2018, 19:25

Hey Mu, it's good to see you back! I must admit I mostly turned my nose up at the Hasu controller when I saw it being reported at about a day's worth of battery. 2-3 days of regular use on a charge is much closer to the kind of life I would expect out of something like that. And will definitely give that a second look. I think the utility of a lot of these keyboards goes way up when you can make them BT or wireless, even moreso when most of my workflow these days has been shifting away from a traditional desktop setup to a more portable Macbook/iPad combo.

User avatar
Muirium
µ

06 Aug 2018, 19:58

I’ll point out that back in spring I was pounding away all day, every day, routinely on that thing for several days straight, and daring it to run out of juice. Not even close! So it’s definitely good for 3 days solid *at least* with a good battery. If I weren’t using it so far away from mains to fall back on, I would have pushed it longer and found out what it’s really got. But no way was I falling back on my iPad screen keyboard while I was busy writing!

Hasu’s controller also has a web UI that even I can stand. My HHKB has a macro that I’ve forever wanted from it: left Command + Escape = left Command + backtick for Mac window switching. Now it matches my Kishsaver and Alps 64. Real danger a genuine HHKB BT would be an awkward downgrade for me! It’d need damping rings too.

See, the HHKB experience has me so rewired that I want a Bluetooth Realforce like never before. It’s getting no love at all these days, so outclassed by my HHKB. But Hasu hasn’t a Realforce BT kit… let alone Novatouch BT!

User avatar
DMA

07 Aug 2018, 07:04

@Muirium I'm aware of one project for custom RealForce PCBs. Just a little more waiting. BT is not currently considered, but can't see why not.

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