Krux DIY Hardware Wallet (Unofficial)

[miner9problems]

I just started playing with Krux I installed on a Maix Amigo and I absolutely cannot get it it to scan an animated QR code from Bluewallet. Started a multisig tx on Bluewallet and trying to get the Krux to sign it and it just won’t read the QR via camera. Any tips?

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[Pmalek]

I just started playing with Krux I installed on a Maix Amigo and I absolutely cannot get it it to scan an animated QR code from Bluewallet. Started a multisig tx on Bluewallet and trying to get the Krux to sign it and it just won’t read the QR via camera. Any tips?

Is it producing any errors after scanning or is it not scanning at all?

The FAQ section on https://selfcustody.github.io/krux/faq/ has a few suggestions regarding QR codes. Please read those and see if that helps.
For instance, Why isn't Krux scanning my QR code?, Why am I getting an error when I try to scan a QR code?, and Why can't my computer read the QR code that Krux displays? 

[dkbit98]

I just started playing with Krux I installed on a Maix Amigo and I absolutely cannot get it it to scan an animated QR code from Bluewallet. Started a multisig tx on Bluewallet and trying to get the Krux to sign it and it just won’t read the QR via camera. Any tips?

Not all QR codes are made equal  
If you don't find any solution on Krux github page than try asking for help in Krux telegram group, they usually reply on questions there.

[odudex]

I just started playing with Krux I installed on a Maix Amigo and I absolutely cannot get it it to scan an animated QR code from Bluewallet. Started a multisig tx on Bluewallet and trying to get the Krux to sign it and it just won’t read the QR via camera. Any tips?

Blue sometimes has bugs, where QR codes merge with dark background, other times the QR would get corrupted if you switch to another app then come back.
Some tips that may help:
- Use Blue on light mode (avoid dark mode)
- Use Nunchuk instead of Blue
- Use anti-glare mode on Krux (press down button on the lateral of the device while scanning to activate anti-glare)

[Meuserna]

I just started playing with Krux I installed on a Maix Amigo and I absolutely cannot get it it to scan an animated QR code from Bluewallet. Started a multisig tx on Bluewallet and trying to get the Krux to sign it and it just won’t read the QR via camera. Any tips?

Have you tried using the Legacy URV1 QR option in BlueWallet, under Settings, General?  I have that turned off and I haven't had a problem with BlueWallet's QRs, but I did have trouble with animated QRs from some other app while testing Krux - sorry I can't remember which though.

For now, BlueWallet is my favorite companion app with Krux, though I need to spend more time with Sparrow too.

I hope you can figure it out, because Krux with an Amigo is by far the most user friendly hardware wallet (signer, really) that I've tried, and with user friendliness comes safety because intuitive design leads to fewer mistakes in my opinion.

[dkbit98]

In Third Wave of Bitcoin Grants there was a good news for Krux wallet, that is one of the ten projects who received grants from OpenSats!
Other Bitcoin projects that received grants are Clams, Fully Noded, Validating Lightning Signer, Fedimint Lightning Gateway, Pickhardt Payments plugin for Core-Lightning, BitBanana, Crack the Orange, Bitcoin Core App and Vexl.

Krux is a free and open-source firmware that enables anyone to build their own Bitcoin signing device via off-the-shelf parts. It runs on Kendryte K210 Risk-V-based devices such as the M5StickV and Maix Amigo, converting them into air-gapped devices that can sign transactions for single and multisig wallets. Krux can also sign messages and has easy-to-use tools to help with the creation and loading of wallet backups.

Users can choose to buy a ready-to-use device—where all they need is to flash the firmware—or make a DIY version themselves. Krux can also run, mainly for educational purposes, on PCs and Android devices.

https://opensats.org/blog/bitcoin-grants-december-2023

In other news related with Krux.
For people who don't know how to flash device and install firmware manually, not there is Krux installer first stable version 0.0.1:
https://github.com/selfcustody/krux-installer/releases/tag/v0.0.1

[Meuserna]

In Third Wave of Bitcoin Grants there was a good news for Krux wallet, that is one of the ten projects who received grants from OpenSats!
Other Bitcoin projects that received grants are Clams, Fully Noded, Validating Lightning Signer, Fedimint Lightning Gateway, Pickhardt Payments plugin for Core-Lightning, BitBanana, Crack the Orange, Bitcoin Core App and Vexl.

Krux is a free and open-source firmware that enables anyone to build their own Bitcoin signing device via off-the-shelf parts. It runs on Kendryte K210 Risk-V-based devices such as the M5StickV and Maix Amigo, converting them into air-gapped devices that can sign transactions for single and multisig wallets. Krux can also sign messages and has easy-to-use tools to help with the creation and loading of wallet backups.

Users can choose to buy a ready-to-use device—where all they need is to flash the firmware—or make a DIY version themselves. Krux can also run, mainly for educational purposes, on PCs and Android devices.

https://opensats.org/blog/bitcoin-grants-december-2023

In other news related with Krux.
For people who don't know how to flash device and install firmware manually, now there is Krux installer first stable version 0.0.1:
https://github.com/selfcustody/krux-installer/releases/tag/v0.0.1

That's FANTASTIC!

Congrats to everybody at Krux.  They deserve recognition for such an amazing project.

For anybody reading along who isn't familiar, pick up a Maix Amigo for around $50 and you've got a touchscreen open source airgapped hardware wallet that is incredibly intuitive and easy to use.  While so many hardware wallets hide features like passphrases, zpubs, receive & change addresses, etc, Krux makes all of that stuff - and more - easy to find.  Oh, and did I mention encrypted QRs?  The large touchscreen on the Maix Amigo is perfect for Krux.  Cheap too.  I got mine for $50.

[dkbit98]

For anybody reading along who isn't familiar, pick up a Maix Amigo for around $50

Maix Amigo is often out of stock and even if you manage to find it on other websites you will probably have to pay more than $50 for it.
Few years ago I was able to find M5stickV for less than $30, and situation was probably similar for Maix Amigo in that time.
I heard Krux team is now working on porting code to some new EPS32 devices.

[Meuserna]

For anybody reading along who isn't familiar, pick up a Maix Amigo for around $50

Maix Amigo is often out of stock and even if you manage to find it on other websites you will probably have to pay more than $50 for it.

I just picked up a second Amigo for $50, shipped, two weeks ago.  They're not that hard to find.  Well, I'm sure stock comes and goes, so maybe I was just lucky?

AliExpress has them for $48, plus $3 shipping.

It'll take a few weeks in the mail, which is never fun, but it's worth the wait.

I love that the Amigo comes with a plastic box, which is a great way to store it when not in use.

[dkbit98]

AliExpress has them for $48, plus $3 shipping.

Yeah I know, but aliexpress is not an option for me right now since they refuse to accept my cards after last refund I requested from them for their shitty service and for not receiving what I ordered  
Device is also not available on official website or on ebay, and all other website I found have much higher price, so I will just pass.
Another thing I heard from other users is their screen is not the best, and it's easy to get malfunctioned or broken.

[odudex]

About the Opensats grant:
It is important to mention that, as Krux creator (Jeff) wants, grants won't go to the project. This one will be for me, to support my work on the project on semester 2024/1.
As Krux has more contributors, both OpenSats and me encourage each one to apply individually for grants, if this is something the contributor aims for.
Krux will never ask for donations or manage funds. It won't be an institution neither have a manager.
Having that said, it will help me a lot and I'm excited to retribute to the community.

Amigo's quality:
From what I know, the quality control is not the best, I've seen some issues with camera (most of them fixed with firmware optimizations, next release will have more of them), I've heard of things like a imprecise touchscreen, a screen with 2 burnt pixels rows.
It still amazes me how they can sell a so powerful and featured device so cheap. I have 4 Amigos, the only issue I had with one of them is a weird power manager behavior, but I still believe it may be possible to fix it with firmware. Some components, like the power manager IC, don't have a English datasheet, so it makes it harder to develop proper firmware.

Porting to Other Devices:
I have the goal to port Krux to another device on this semester, it may be an ESP32. But ESP32s are too weak to run video applications. Jade got QR codes signing working with pure C, on a tiny screen. But with Micropython, in larger screens, I would say it is almost impossible to make it work.
An Amigo's competitor like LILYGO® T-Display-S3-Pro costs the same as Amigo, but the MCU has ~half processing power, the screen is smaller, the camera is worse (the same as Amigos's frontal camera).
One possibility to run Krux on cheap and available ESP32s is to make a "blind Krux" version that works with SD cards as the only way to sign PSBTs.
Other port possibilities are OpenMV's Cam H7 and Arduinos Portenta and Nicla Vision. Running with ARM on ST MCUs at 480MHz, these devices are compatible with openMV, which make them very suitable to run Krux. The problem is that, with cameras and displays, these devices will cost 2 or 3 times an Amigo.
There are also other cheap and powerful RISCV devices, like Milk-V and Sipeed's M1sDock but they lack Micropython support and documentation.
Effort will be required to enable cheaper signers. I'll be on it, I know Keith from SeedSigner will be too on his Micropython research.
Soon boards with better chips will be launched, like ESP32 P4 and Amigo's K210 successor, the Kendryte K230. Let's keep improving with them!

[n0nce]

Amigo's quality:
[...]
It still amazes me how they can sell a so powerful and featured device so cheap.

The cool thing about repurposing these types of devices is that the hardware is often subsidized through the software. I.e. users 'pay off' the hardware through their software-/in-app/similar purchases. So if you can re-flash them with something custom, you sometimes get hardware at an incredible value.

Now that I think about it, I'm actually not sure if this devices comes with some proprietary software ecosystem; I might be mixing stuff up.

Some components, like the power manager IC, don't have a English datasheet, so it makes it harder to develop proper firmware.

Feel free to send them (part numbers and / or datasheets) to me in direct messages; I might be able to work something out on that front.

[Meuserna]

It is important to mention that, as Krux creator (Jeff) wants, grants won't go to the project. This one will be for me, to support my work on the project on semester 2024/1.

You deserve it.

The work you're doing is phenomenal.  It was one of your betas that got me to buy an Amigo and start using Krux and I've been a huge Huge massively HUGE fan ever since.  You're making rock solid security easy, and I cannot overstate how important that is.  Thank you for the work you're doing.

As for the Maix Amigo...

The quality of Amigo hardware isn't the best, but it'd be RIDICULOUS for anybody to compare a $50 device to a luxe $1,000 metal and glass device like an iPhone.  I paid less for my Amigos than I paid for a Blockstream Jade, and the quality is higher, not to mention the usefulness of that huge touchscreen.  Krux on an Amigo is such a killer combo.  The only thing holding this project back is that more people don't know about it.  Everyone I've introduced to Krux on an Amigo has been blown away by how easy and intuitive it is.

Amigo's quality:
It still amazes me how they can sell a so powerful and featured device so cheap. I have 4 Amigos, the only issue I had with one of them is a weird power manager behavior, but I still believe it may be possible to fix it with firmware.

I have 2 Amigos, and I'm experiencing that issue - or something like it - with one of them.  It's weird, actually.  My first Amigo had trouble turning on.  Sometimes it wouldn't power up until I plugged it in via usb even though the battery was fully charged.  But, for reasons I do not understand, that issue went away and hasn't been an issue since.  Maybe updating Krux firmware solved it?  I don't know, but my first Amigo has been flawless ever since.

My second Amigo has the power issue.  When I turn it on, a light on the back (or maybe inside the device?) flashes, but it doesn't power up.  The only way to get it to turn on is to plug it in via usb, but once it's on it doesn't need to be plugged in.  It's not a problem for me since the device works perfectly otherwise.

And speaking of owning more than one Amigo...  I love that Krux offers different color themes.  At first, I thought that feature was silly, but now that I have 2 Amigos, I like using a different theme for each to make it easier to keep track of which is which.

[kkdao]

AliExpress has them for $48, plus $3 shipping.

Yeah I know, but aliexpress is not an option for me right now since they refuse to accept my cards after last refund I requested from them for their shitty service and for not receiving what I ordered  
Device is also not available on official website or on ebay, and all other website I found have much higher price, so I will just pass.
Another thing I heard from other users is their screen is not the best, and it's easy to get malfunctioned or broken.

That's too bad you're having an issue with aliexpress and cannot get one, they have always been in stock there for $50. Next time you come across other users having issues with their Amigo send them to our Telegram channel, or reach out to our Twitter account, okay amigo?

[odudex]

The cool thing about repurposing these types of devices is that the hardware is often subsidized through the software. I.e. users 'pay off' the hardware through their software-/in-app/similar purchases. So if you can re-flash them with something custom, you sometimes get hardware at an incredible value.

Now that I think about it, I'm actually not sure if this devices comes with some proprietary software ecosystem; I might be mixing stuff up.

Feel free to send them (part numbers and / or datasheets) to me in direct messages; I might be able to work something out on that front.

The manufacturer(Sipeed) does not have a proprietary ecosystem, but a fork of opensource ecosystems (Micropython + OpenMV). OpenMV does have their own hardware, which probably subsidizes the software development, so unless Sipeed donates to openMV it could be considered unfair with OpenMV.

The component we're having issues with is AXP173 PMU, you can find more details about the issue in a post I made here:
https://forum.seeedstudio.com/t/maix-amigo-wake-from-sleep-wont-work-in-some-devices-axp173-pmu/273808

[odudex]

My second Amigo has the power issue.  When I turn it on, a light on the back (or maybe inside the device?) flashes, but it doesn't power up.  The only way to get it to turn on is to plug it in via usb, but once it's on it doesn't need to be plugged in.  It's not a problem for me since the device works perfectly otherwise.

Thank you for your feedback! I hope we find a solution for this and we all have a better UX with Amigo!

[odudex]

Power button issues reported above should be solved on version 24.04beta14.
Now after shutdown via menu, to turn it on again, for all devices, it's only necessary to hold power button for 1 second.

[Meuserna]

Power button issues reported above should be solved on version 24.04beta14.
Now after shutdown via menu, to turn it on again, for all devices, it's only necessary to hold power button for 1 second.

Yup.  That solved it for me.

I own 2 Amigos.  One of them has this weird power bug & one doesn't.  When powering on the Amigo that DOES have this bug, the device always does a strange flash of light from the back (is that a flashlight below the rear camera, or is it just a bright LED?).  It used to flash a blip of white light, and then nothing.  Now, with your fix, it flashes with a blip of white light from the rear of the device, and then powers on.  When powering on my other Amigo which DOESN'T have this bug, it just powers up - there's no flash/blip of white light from the back of the device.

Oh, and nice, you've added a screensaver since I last updated (or maybe I just haven't left my Amigo running idle).  It's been sitting on my desk as I type this, and the screensaver just came on.  Well done.  The option to Wipe Device is a nice addition too.

You're doing such great work.  Krux is fantastic.

[odudex]

Amigos have a strong white LED flash light in the back, when scanning QR codes you can press ENTER physical button to turn it on. Can be useful to scan paper QR codes in dark environments.
I noticed some of them blink when starting up. It's probably due to a random state of IOs while the device is getting powered up. Sipeed should have used a pull down resistor on the LED transistor driver gate(I checked the schematics and it is missing). Maybe there's a firmware hack to avoid this glitch, but I wouldn't worry about it. The behavior changed on beta14 because now Amigos go to a deeper level o "shutdown".

Another dev, Tadeu created the screensaver. On beta14 I did some optimizations for it to use less resources too. It's useful to grab your attention and don't forget to turn the device off.

Glad you liked the changes!

[Meuserna]

Can I do a feature request here?

I'd love to see BIP85 added to Krux.  I'm currently using a Blockstream Jade for BIP85, but Jade, just like all of the devices I've found that do BIP85, makes the process incredibly cumbersome.  I'd be thrilled to see a Krux implementation where, using the loaded seed as a parent seed, the user inputs a BIP85 index number & chooses whether they want a 12 or 24 word child seed, and they're given the child seed's seed words and options to save them (QR, encrypted QR, save to micro SD).