Devices and Part List

Krux Compatible Devices

Comparative Table

Device	M5stickV	Maix Amigo	Maix Dock	Maix Bit	Yahboom k210 module
Price avg.	US$50	US$55	US$35	US$35	US$60
Screen size / resolution	1.14" / 135*240	3.5" / 320*480	2.4" / 240*320	2.4" / 240*320	2" / 240*320
Touchscreen		Capacitive			Capacitive
Camera	OV7740	OV7740 rear GC0328 front	GC0328	OV2640 or OV5642	OV2640
Battery	200mAh	520mAh
Requirements	None	None	Rotary encoder 3D printed case Soldering Assembly	Buttons 3D printed case Soldering Assembly	None
Warnings				Camera has lens distortion	Micro USB

: M5stickV's USB-C port lacks pull up resistors required for it to be recognized and powered by host (computer) USB-C ports. If you don't have an USB-A available, you can use a USB hub connected between your computer's USB-C and M5stickV.

: Some Amigo screens have inverted X coordinates, others display colors differently. For more info see FAQ

: Some stores ship the Maix Dock with soldered pin connectors that do not fit into the 3D printed case

All devices feature Kendryte K210 chip: 28nm process, dual-core RISC-V 64bit @400MHz, 8 MB high-speed SRAM, DVP camera and MCU LCD interface, AES Accelerator, SHA256 Accelerator, FFT Accelerator.

M5StickV

Below is a list of some distributors where you can find this device:

• M5Stack
• Mouser
• Digi-Key
• Elektromaker
• Lee's Electronic
• AliExpress
• ABRA
• Adafruit
• Cytron

Maix Amigo

Below is a list of some distributors where you can find this device:

• AliExpress
• Seeed Studio
• Digi-Key
• Mouser
• Electromaker

Yahboom k210 module

Below is a list of some distributors where you can find this device:

• AliExpress
• Amazon
• Yahboom Store
• ETC HK Shop

Maix Dock and Maix Bit

For the DIYers, the Maix Dock and Maix Bit are also supported but will require sourcing the parts individually and building the device yourself.

Below are example implementations with instructions on how to recreate them:

• https://github.com/selfcustody/DockEncoderCase
• https://github.com/selfcustody/MaixBitCase

Below is a list of some distributors where you can find these devices:

• Mouser
• Electromaker
• Digi-Key
• AliExpress
• Amazon

Other Parts

USB-C Charge Cable

This will be included with the M5StickV and Maix Amigo that you purchase from one of the distributors above. It will be necessary to power and charge the device and to initially flash the firmware.

(Optional) MicroSD Card

We cannot guarantee that a microSD card is compatible and will work in your device; you'll need to test it on the device to be sure, read the FAQ for more info. The size of the SD card isn't important; anything over a few megabytes will be plenty.

(Optional) Thermal Printer

Krux has the capability to print all QR codes it generates, including those for mnemonics, xpubs, wallet backups, and signed PSBTs, using a locally-connected thermal printer via its serial port.

Many thermal printers may be compatible, but currently, the Goojprt QR203 (easily found on AliExpress) has the best support. The Adafruit printer starter pack can also be a convenient option to get started, as it includes all the necessary components for printing (except the conversion cable). To ensure proper functionality, enable the printer driver in the Krux settings, set the Tx pin and baud rate value to either 19200 or 9600, as explained in this Adafruit printer tutorial. You will need to connect the device's Tx to the printer's Rx and ground. The printer requires a dedicated power supply, typically with an output of 5 to 9V and capable of supplying at least 2A. For more information, see this discussion.

(Optional) Conversion Cable for Thermal Printer

To connect the printer to the device, you will need a conversion cablewith a 4-pin female Grove connector on one end (to connect to the device) and 4-pin male jumpers on the other end (to connect to the printer). For a more reliable connection, it is recommended to cut and solder the wires of your custom cables instead of using jumpers.