Anyone interested in an ADC-based capsense controller?

DMA · 06 Jun 2016, 09:20

..should I close this thread and move to workshop? Looks like it belongs to workshop.

Halvar · 06 Jun 2016, 09:23

Chip prices are good to know for a mid-term perspective, but is building controller hardware now part of the plan?

For me, the main appeal of this is the cheap off-the-shelf prototyping board that has all the hardware I need for a Model F controller and maybe for a beamspring controller. Much like the Teensy with hasu's or Soarer's firmware.

tigpha · 06 Jun 2016, 17:38

DMA wrote: ..should I close this thread and move to workshop? Looks like it belongs to workshop.

You will find that instead of one thread, you will need to follow two because both will attract comments at once. I don't think there's any need.

tigpha · 06 Jun 2016, 17:47

Halvar wrote: For me, the main appeal of this is the cheap off-the-shelf prototyping board that has all the hardware I need for a Model F controller and maybe for a beamspring controller. Much like the Teensy with hasu's or Soarer's firmware.

I agree that the single chip solution is very appealing. I also feel that the 8-bit 32Kb ATMEL 32u4 is overpriced compared to the features on offer with 32-bit 128Kb ARM Cortex-M3 class chips. ATMEL about £5 vs. Cypress Cortex-M3 about £6 to me weighs in favour for ARM.

DMA · 06 Jun 2016, 19:11

Halvar wrote: Chip prices are good to know for a mid-term perspective, but is building controller hardware now part of the plan?

For me, the main appeal of this is the cheap off-the-shelf prototyping board that has all the hardware I need for a Model F controller and maybe for a beamspring controller. Much like the Teensy with hasu's or Soarer's firmware.

It will always work on those kits. It has 2 advantages over teensy, btw: 1) it costs little more than half as much, and 2) if you only need 12 pins and don't mind constantly lit yellow LED, you can make something else from the programmer - which is CY8C5688, just below the top of the line. It has CAN interface and LCD driver - scangauge, anyone? I currently use two of mine as ADB-USB converters

But now it looks like there is a demand for this controller from people with less soldering skills. For them it will surely be beneficial if it would be a board with a connector which they can just plug in (probably supporting xwhatsit's extension header/other extension headers. LED drivers, for example. Since it has capsense - probably some crazier stuff like volume sliders on the side of the keyboard or something even more weird).
For people with a bit more skills - controller integrated onto the sense PCB would make sense. This becomes even more attractive given the size of the chip and amount of external components required.

Those latter will benefit from cheaper chips. The controller doesn't need 20bit delta-sigma ADC or opamps or tons of UDB blocks. It needs some - but even cheapest PSoC5 LP chip has more than this one needs.

One of the best things about the psoc creator that you can switch the chip on the fly, remap pins, recompile and you're set. For bootloader you don't even need to remap pins, because it only uses USB pins and those are fixed-function and assigned automatically.

Techno Trousers · 06 Jun 2016, 19:47

Yep, controller integrated into an FSSK/FEXT PCB would be the ultimate dream for me. There is a potential market of thousands of people who would want a drop in Model F unit to upgrade their Model M chassis. If the PCBs can be ordered with the controller already baked in, it will reduce cost and complexity of that project considerably.

Muirium · 06 Jun 2016, 20:00

One-upmanship: My ultimate dream Model F requires Bluetooth. USB is a solid step, but I'd still like the freedom to attach a future controller. Wonder if we can do both!

@DMA:
I can move this thread to the Workshop if you like. Or if you'd prefer to start a fresh technical thread there, go ahead. And I'll ask my man in California if he's up for digging out my XTant bits for a weird handover…

Techno Trousers · 06 Jun 2016, 21:03

F-122 on your lap in the living room?

Muirium · 06 Jun 2016, 22:55

Little smaller than that:

Besides, I loathe wires in general. Even on my desk. They're trouble just waiting to happen. Mostly when I pick up a board to put it away and plain forget the damn things exist, yet again…

DMA · 07 Jun 2016, 02:20

No need to move the post, I'll just create proper workshop post then when it comes to actual prototyping.

One-upmanship is understandable motive. BT is much trickier though - it's a damn RADIO, and even putting certification aside (FCC will frown at us for that, but hey, we're not going to sell it) all those ether-related things are still magic, even in 21st century.

USB and BT in the same controller will just make it twice as expensive with half of the battery life. Can't find a chip with BT _and_ USB, so it will have to be more than one.
Although I can see some use for that - one don't have to have SWD programmer on hand in case firmware decides to do something stupid, for example.

But first. But first. Ban me from this forum, I need to finish at least v0.1 of the controller. Or very soon I'll have 3 excellent keyboards in my hands and no way to actually use them!

Muirium · 07 Jun 2016, 11:42

What I mean is:

If (USB controller is integrated into main Capsense PCB)
I'd like a way to bypass it with a future controller, with untold capabilities
else
No worries, I can swap them

It's integration that I'm on about. Vintage controllers can be a showstopper when they're integrated to the PCB. They're not designed with the future in mind. They won't simply lie quiet when unpowered, while monkey business is going on downstream in the matrix!

DMA · 07 Jun 2016, 17:42

Muirium wrote: What I mean is:

If (USB controller is integrated into main Capsense PCB)
I'd like a way to bypass it with a future controller, with untold capabilities
else
No worries, I can swap them

It's integration that I'm on about. Vintage controllers can be a showstopper when they're integrated to the PCB. They're not designed with the future in mind. They won't simply lie quiet when unpowered, while monkey business is going on downstream in the matrix!

There can be a tearline on the PCB with contact pads(under the solder mask? Or just exposed gold?) along it. F.E. it can be in the LED area. I just think that it would be somewhat cheaper to produce them as one piece.

..gold will probably make it _more_ expensive

So under solder mask. It's removable, after all.