Add Coldcard Q

[siim-m]

Adds Coldcard Q to the list of hardware wallets.

[crwatkins]

Thanks for the submission! What's the current status of the Coldcard Q?

• Is there user documentation available? I couldn't find any Coldcard Q usage documentation on the Coldcard web site.
• Are there any specifications published such as QR code compatibility and companion wallet app compatibility?
• Has the Coldcard Q been officially released? When is/was the release date?
• Where are the firmware release tags for Coldcard Q deterministic builds? I found the branch, but could not find any tags.

[scgbckbone]

Thanks for starting the review.

Thanks for the submission! What's the current status of the Coldcard Q?

Already shipping and thousands of units already shipped out. Due to higher demand than anticipated we haven't switched from reservation mode in the store just to manage the inflow. Hopefully in a few weeks should be switched.

• Is there user documentation available? I couldn't find any Coldcard Q usage documentation on the Coldcard web site.

It's very similar to Mk line, being slowly improved and more features added. They share the same firmware and architecture with the extra hardware capabilities. (more already there since this thread started)

• Are there any specifications published such as QR code compatibility and companion wallet app compatibility?

• Address verification is "text" so everything already works, and it also supports BIP-21 url format
• QR PSBT binary or base64, Signed TXN hex already works
• BBQr PBST is bbqr.org has a support table (sparrow & Nunchuk and zeus on public master and with more wallets coming)
• SeedsQR also capable
• Bar code capable

• Has the Coldcard Q been officially released? When is/was the release date?

We've had units commercially out for over 3 months now, with test units out for many months.

• Where are the firmware release tags for Coldcard Q deterministic builds? I found the branch, but could not find any tags.

Thanks for noticing, although it is reproducible we didn’t have the tags there when you first reviewed, they were subsequently added https://github.com/Coldcard/firmware/tags

As a note we have already merged the Q & Mk branches into master as they are the same code base with different hardware targets.

[crwatkins]

In regards to the documentation, let me be clear that there aren't any specific listing criteria relating to documentation, so these are just some observations.

It's very similar to Mk line, being slowly improved and more features added. They share the same firmware and architecture with the extra hardware capabilities. (more already there since this thread started)

Given the fact that thousands of units have been shipped out, I'm surprised to find no mention of the device in any of the Getting Started guides listed on the website printed on the box. As a "new user", the guides I was referred to told me to plug in the USB and it would power up. It didn't. I was concerned the device was faulty, so I put in batteries. It would have been nice to have had suggestions or requirements relating to the batteries (alkaline, lithium, NiMH). I looked for a power button and pressed it and the screen didn't come on. Now I was really concerned the device was faulty. It turns out I didn't press the power button long enough. After some more fumbling it came on. All of this could have been avoided by trivial updates to the existing documentation.

Likewise, given the fact that one of the major new features is the QR scanner, it was disappointing to note that Coldcard Q is actually not QR compatible with most of the wallets listed on the Compatible Wallets page. Scanning transactions displays the text "Above is text that was scanned. We can't do any more with it." I believe that even the most minimal amount of guidance for new users could eliminate a lot of confusion and frustration.

[nvk]

Thanks for the feedback Craig.

1. You raised some good specific items that should be added (battery and power button). Aside from the very few specific things, it's the same flow and features as mk4. Those getting started guides were written years after Mk was launched. We don't build docs and devices in unison because the amount of community generated content and team bandwidth. Ben Sessions and others already have videos on setup. But more is coming!

2. re: QR, Just as with PSBT had no adoption when Mk was launched, it takes years to push standards. It's a low time preference game. The market has grown alot and I doubt that all things will be compatible with all things. look at BitKey, which will be massive but only works with their own app. On the bright side there is alot of work being done to integrate QR and NFC in some of the clients on that list. Heck core didn't do PSBT support till recent. And we still don't have a QR BIPs...

nice example of third party video by Unchained https://x.com/unchainedcom/status/1786397489676845243

[crwatkins]

What is the official release date that should be used in the review?

[nvk]

We never really announced it, just started shipping. I think we can use Feb 8th 2024 as it was likely the most we talked about shipping public.