[IC] Dave's QMK, USB-C fc660c controller

Hey folks,

I’m looking to get a couple of @Dave’s fc660 controllers made, figured I’d check if any others would like to help fill out my order from JLC.

What: Dave’s fc660 controller. A modified HASU controller with USB-C, extra pins broken out, a plug for RGB control, and custom footprint for RGB mod. I’m thinking purple solder mask, but am open to feedback.

When: I’m currently waiting for some substitute 20-pin connectors to come in so I can confirm they are compatible. If it all works on time, I expect to place an order in the first or second week of December.

Price: As of today, it’s looking to be $30ish, not including the cost of shipping from me to you. With any luck, conservatively I would have them to you by the end of January (hopefully sooner, depending on the holiday mess).

What I need from you: Just drop a line here if you’re interested. I’m just trying to get a rough head count for my order. I can then reach out and verify details when I’m ready to order.

Happy to answer any questions you may have.

As always, many, many thanks to @Dave for sharing his work with us.



These are really great and make adding RGB backlighting so easy. Highly recommended.



I live in the UK and am certainly interested in one or two copies of Dave’s FC660C controller. Have a case that I’ve been itching to light up.

Happy to register my interest!

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Did you have to widen the Heavy-6 USB cutout to accommodate the USB-C port?

Put me down as a most likely.

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Yes, but it was really easy with a small, round file. You can buy whole sets of them for less than $10 usually.

Okay cool. And no issues with cracking or anything? I know PC is less likely to crack than Acrylic, but it still freaks me out.

It was a tight fit, but I managed to use USB-C in the H6 without modifying the cutout. Ymmv. But it should be fine to file down, just take small bites and it’ll go quickly.

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No, no cracking. Just go slow, no power tools needed or advised.

fwiw my experience

Heavy 6 Polycarb (I did NOT have to modify the opening)

Not sure about the metal version, I do not have one. Try sticking a usb-c cable in the usb hole to see if it fits.

Leopold Stock case: Required slight filing


Excellent, I’d definitely be interested in one of these, thanks.

The opening on mine needed just a touch of widening. I’d take a picture, but getting the NetDot plug out of there is a PITA.

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Excellent. I have you, @cmoore1, and @fatalruin down. After I confirm part compatibility I’ll reach out.


I’m in for one as well.

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I would be interested - just want to know how the rgb works since the original board doesn’t have any. We have to solder them or something? (No idea how that can work)

It takes a little soldering, just for the connector. The LEDs themselves come with sticky / tape back and you can just peel and stick.

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Parts confirmed to work. PCB order placed, will update when arrived and ready to ship out. Expect new year conservatively.


I’m interested, do you have any left unaccounted for?

They’re getting their MCUs soldered right now, but I should have a couple spares. I’ll reach out after I have them in hand.


@rooski15, thanks on behalf of the community for your efforts here! I would truly love to jump on the order list.

I have many Topre boards (about 5 Realforces, HHKB, and FC660C)…but tragically my FC660C has never worked reliably due to the infamously flimsy mini-USB jack. I never even bumped it, and I didn’t have the time to send it back.

I love the board deeply for both its feel and look, and would be incredibly excited to get it working again. While I’d been looking into resoldering the original, this upgrade adds so much functionality and modernity that it is clearly the best option! Let me know the status of your run :).