Mark II Dev Kit

The Mark II Dev Kit is intended for Software Developers and Hardware Developers to develop on the Mycroft platform.

The following documentaion is for the Mark II Dev Kit and the software that was initially distributed with those kits. For Mark II production units please see the dedicated documentation at:

Known Issues

The software on the Mark II Dev Kit is still an early release. Please help us improve the Mark II by opening a bug report or feature request for anything that doesn't seem right.

There are a number of known issues that we are working through at the moment. These are documented as issues on this repository.

Constructing your Dev Kit

Being a development kit, there's a small amount of construction required.

We have put together a detailed set of instructions to help get you setup. These instructions include the laser cut enclosure, 3D printed audio chamber and camera module.


The Mark II, including the Dev Kit, comes with 3 buttons and 1 switch. These are all located on the SJ201 board.

  1. Action - the button located in the center of the LED ring. This activates the listener if needed.

  2. Volume Up - the button on the front-right of the board when looking at the screen.

  3. Volume Down - the button in the front-center of the board.

  4. Mic hardware cut-off - a physical disconnect switch for the microphones. Switch left to disable the microphones, and right to re-enable them.


The SJ201 comes with 12 LEDs in a ring formation.

Currently there are two "dedicated" LED's for development purposes only (these will change as we approach a general release):

  • One led is green/red representing the current state of the microphone mute.

  • The second shows the general CPU temperature

    • Blue = cold

    • Magenta = warm

    • Orange = hot

    • Red = very hot

The LED ring has a number of states:

  • Blue and spinner - listener is activated such as when the wake word is detected.

  • Pulsing ring - device is thinking.

Further information

You can find detailed information on all components of the Mark II hardware on our Github.


Installing the Operating System

WARNING: The software that was distributed with the Mark II Dev Kits when they were released in 2021 should not be used on a production Mark II. It is recommended to use the latest production software.


  • The Dev Kit software WILL NOT WORK on a production Mark II.

  • The production software WILL WORK on Dev Kits as well as production Mark II's.

  • Mycroft Sandbox images WILL WORK on Dev Kits as well as production Mark II's.

To use the latest software distributed with the production Mark II's see the dedicated Mark II documentation:

Using a tool like the Raspberry Pi Imager, flash the downloaded image onto the USB drive provided with your Mark II Dev Kit. To get the most from this drive, be sure to plug it into the top left USB port which is blue indicating it is USB 3.0.

First boot

‌When you power on the device for the first time, Mycroft will walk you through setting up your WiFi and pairing the device to your Mycroft account. If you haven’t yet registered, you can create an account at

SSH Access

To enable secure access to your device, we use public-key cryptography rather than a default username and password.

In short this means that you generate what’s known as a key-pair. The pair is made up of two files - a public key and a private key. The public key is transferred to your device, and only your private key will be able to log in to it. Your private key is like an extremely secure password and you should never share this with anyone. If you want to learn more about the details, start here.

Generating a key-pair


  1. Open your terminal and run: ssh-keygen -t rsa

  2. You will be asked where to save your new key-pair Leave this blank if you would like to use the default location /home/user/.ssh/id_rsa

  3. You can optionally add a passphrase. This is an additional layer of security that will require you to enter your passphrase when using your private key.

  4. If you selected the default file path you will have two new files: /home/user/.ssh/id_rsa is your private key - again do not share this. /home/user/.ssh/ is your public key - this can be shared.

Public Key Contents

If you read the contents of your public key it will look something like this:

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDSUOctoVJ5nwQO0I9c8gIK0ijYbOCZKdVmAu8jG0Znl2zvZLFYI7bGFbt/Rr8vjFVh4I2srFB52duirX53LtZF2ZUKMI+8ivaLk+pD7M0WL+sbG1jU2S/IdCUi7HmZ/fSp89UJb23i9Q9AINFdw+0spCjJSWB8+3wGQ4bPUSbNLCtsYv1anO+B26PIN5E9R0X84IVq+x41B1swvlUt15zfMwA7Jhl5fJgl6XzhNYcMdH/qp+r7Ij2d7NM9YR6/yva4/QLqzbPCoelxJLpVHKZ0ZLnhvYOoxRbLbU46AgTljGM3Z7rcvxm2Vl107ZojljuvF6cMXM4NU4peVimn5XOP gez@example This includes three things:

  • The encryption protocol used - ssh-rsa

  • The public key - a seemingly random string

  • An identifier of the creator - gez@example

Adding your public key to your Mycroft account

Now that you have your key-pair setup, you can add it to any of your Mycroft devices at:

Your Mark II device will then fetch this public key from your Mycroft account.

SSH in to your device

With your public key on your Mark II, and your private key remaining securely on your local machine, you can now SSH into the device.

You can find the IP address of your device by saying "Hey Mycroft, what is my IP Address?".

ssh -p 8222 mycroft@$YOUR_IP

You will now be logged in as the mycroft user, with the virtual environment active. Your prompt should look like:

(.venv) mycroft@localhost:~$

From here you can interact with the device as you would any other Linux system.

Multiple containers

There are 3 areas that make up the operating system on your Mark II:

  • mycroft container - contains everything you would expect and is built on a base of Ubuntu 20.04.

  • awconnect container - contains the WiFi setup application and manages the network connections.

  • _pv_ (Pantavisor) initrd view - boots the system, manages the other containers as well as updates.

You can SSH into both of these containers and the initrd view by using the container name as the username. For example to SSH into awconnect you would run:

ssh -p 8222 awconnect@$YOUR_IP

Or to SSH into the Pantavisor initrd view you would run:

ssh -p 8222 _pv_@$YOUR_IP

There is also a BSP layer that can be mounted for inspection on another machine. This contains the kernel, modules and firmware.

Transfer files to or from your device

Now that you have SSH access, you can transfer files to and from your device using scp.To do this, we also need to use the port 8222, however unlike ssh the scp command uses the uppercase -P flag 🤷

Lets transfer my_file from our computer, to the Mark II device:

scp -P 8222 my_file mycroft@$YOUR_IP:/destination/path/

We can also transfer files in the other direction. Let's grab all of the Mycroft log files in one command using the -r recursive flag:

scp -rP 8222 mycroft@$YOUR_IP:/var/log/mycroft /destination/path/

Beta Testing

The Mark II is currently only available as a development kit and we know that many of you are keen to get the latest software as soon as possible. There are two ways that you can help out by testing the latest software.

Operating System

To get the latest version of the Mark II's OS, including updates to Mycroft-core on a daily basis - head to your device settings on Select your Mark II and under "Software release" select "Latest".


To test out the latest Skill updates before they are released to the public Marketplace - first SSH into your Mark II, then run:

mycroft-config set skills.msm.repo.branch dev

This command updates your Mycroft configuration to use the "dev" branch of the mycroft-skills repository.


If you are having problems with your device and would like to share the system logs with the Mycroft team you can enable remote logging. This includes your Mycroft log files that will include utterances spoken to the device and responses spoken by Mycroft.

Fetching logs from the USB

In the event that a device cannot boot or is otherwise inaccessible, you can get the logs by plugging the USB drive directly into your computer. There are two partitions on the disk:

  1. pvboot

  2. pvroot

pvroot/disks/perm/mycroft/lxc-overlay/upper contains the modified file overlay for the mycroft container. This includes your usual Mycroft logs.

Turn on remote logging

  1. Shutdown the device and plug the usb into a computer

  2. In the pvboot partition, edit cmdline.txt change the final




Find your Device ID

The fastest way for us to find your device is by the device-id. To get this, login to the main mycroft container:

ssh -p 8222 mycroft@$IPADDRESS

Then print out your device-id using the following command:

sudo cat /pantavisor/device-id 

Device ID from USB

Plug the USB drive into your computer and find the pvroot partition - the path of this partition is represented below as $PVROOT_MOUNT_POINT. To get your device-id run:

sudo grep "" $PVROOT_MOUNT_POINT/logs/current/pantavisor/pantavisor.log

GUI Debug Info

The GUI logs are available in: .local/share/sddm/wayland-session.log

Skill Development

Creating your first Skill

To create your first Skill run:

mycroft-msk create

Then see our detailed Skill development documentation:

pageVoice User Interface Design Guidelines

Installing Skills still in development

Mycroft Skills Manager (MSM) is a command line tool used to add, manage and remove Skills on any Mycroft installation. It can install any Skill listed on the Mycroft Skills Repository or from any Github repository.

pageMycroft Skills Manager

Creating a custom idle screen

The idle screen (also called a Home screen) on the Mark II is fully customizable. The default screen is provided by the Time Date Skill but you can create your own.

Here we have a simple example Skill that allows the user to set their idle screen to be an image from a remote url through the Skill's settings.

To switch between the available screens, pull down from the top of your screen to access the on device menu and select Additional Settings > Homescreen. As new options are added to Skills they will automatically show up in this list.

Emulating the Mark II screen on desktop

If you are developing a Skill on another computer and want to emulate the display of the Mark II, you can launch the Mycroft GUI using the following arguments:

mycroft-gui-app --width=800 --height=480 --hideTextInput

Mycroft-Core Development

Before making changes to mycroft-core on the Mark II Dev Kit it's recommended that you disable automatic updates in your device settings.

To return to a production state, it is recommended that you flash a fresh image of the Mark II OS.

Mycroft-core is installed at /opt/mycroft/

The Mark II is currently using a feature branch of mycroft-core that includes all the hardware level compatibility code, and a few other tweaks that aren't ready to be merged into the mainline as they may impact other devices that run Mycroft.

The HEAD of the mycroft-core git repo will be in a detached state. This does not change the code that is running. It means that the local repo is currently pointed to a specific commit (eg "27cf725"), rather than a branch pointer (eg "feature/mark-2") which in turn points to a commit. You can "reattach" the HEAD by checking out the branch pointer rather than the commit. In short, run:

git checkout feature/mark-2

If you are testing changes to mycroft-core, these will need to include the updates from that feature branch. Hence you can either branch off feature/mark-2

git checkout feature/mark-2 
git checkout -b my-new-branch-name

or you can merge the changes from one branch onto the other:

git checkout feature/mark-2
git merge my-new-branch-name

Finally, any time you are making changes to Mycroft-core - whether that is on the device, or by copying files to a running instance (eg via scp) - it is recommended that you restart the relevant Mycroft service:

mycroft-start restart <service-name>

You may also restart all services just to be safe:

mycroft-start restart all


How are updates handled?

Automatic updates can be disabled or re-enabled from the Device Settings in your Mycroft account.

By default, your Mark II checks for updates on a regular basis. When an update is available, it will apply it after a preset delay.

When requesting an update your device will fetch this directly from Pantacor’s servers. As we've always done, connections are initiated by the Mycroft Mark II. The server cannot initiate a connection with a device.

Who are Pantacor?

The Mycroft Mark II uses Pantacor to provide system updates.

Mycroft has partnered with Pantacor to provide a comprehensive and robust software life-cycle management solution. It is an open source solution that uses container technologies to securely and reliably maintain edge services on Linux devices.

For the Mark II this provides a very stable and resilient operating system and update service. If something goes wrong on your Mark II, the device will automatically roll back to a previously working state.

The team at Pantacor share our commitment to open source, privacy and security. Pantacor’s co-founders also have a strong reputation to back that up. Furthermore, as they are constituted in Europe, they must also meet the EU’s strict regulatory guidelines including the GDPR.

Do I need an account with Pantacor?

No, your Mycroft account handles everything and is the only account you need.

What is pantavisor?

Pantavisor is open source software from Pantacor that manages the containers on your device and handles the update processes. You can find the source code for it here on Pantacor’s Gitlab.

In more technical terms, Pantavisor is a device-side initrd base system which assembles a userland made up of one-to-many containers. On the Mark II, it starts the awconnect container, providing networking and connectivity, and the mycroft container that contains everything that runs the Mycroft application including mycroft-core, mycroft-gui, Skills and all the dependencies for these.

For further information on Pantacor check out:

What is device cloning?

Pantacor provides a method of cloning the configuration or “factory state” of a device, or any pristine update state that is available for a device. This is the configuration and other static assets used to generate or update an image. It does not, and cannot, clone the contents of your device. It cannot read your filesystem. A “clone” does not contain any of your Skills, Skill settings, data or other files.

Device cloning would not be useful to perform on any end-users device. It is only useful during development to share modified system configurations with other developers.

Are you monitoring my usage?

By default Mycroft does not retain your usage data. Unlike some other companies that we won't bother to name, you don't need to search through application settings to turn off data collection. If you haven’t explicitly opted-in to share your data with us, then we do not keep it. Any queries sent to our back end services are processed and then deleted immediately.

General usage statistics, such as how many unique devices have connected to our servers in a given day are collected and kept in aggregate. This allows us to see general user trends, but again, if you haven’t opted-in we would not know whether any device from a specific account was even turned on any previous day.

Our privacy policy outlines in greater detail how and when we collect and store your information.

How does the SSH connection work?

In developer mode, the Pantavisor system provides an SSH bridge running on port 8222. This bridge allows you to enter a shell session into any running container, regardless of whether that container is running an SSH server by itself. Due to the developer-friendly nature of the Mark II, this is enabled by default however no access is allowed until an SSH key is added to the Mycroft management panel.

In previous devices like the Mark 1, we provided the ability to turn SSH on and off because they operated off a default username and password. Distributing an internet connected device with a default username and password providing shell access is a very big security risk. Hence the SSH service had to be disabled by default.

The use of a key-pair removes the need to disable the SSH server. Without a public key on the device, and the ability to connect to your device on port 8222, no one can SSH into it.

I used a different Raspberry Pi and it won't boot!?!

First, we recommend using the Pi that ships with your device.

If you need to switch this out, please note that there are some revision 1.4 Raspberry Pi's that ship with firmware that does not support USB boot. To update the firmware, you can flash the Mark II image onto a Micro SD card. This will automatically update your firmware to a supported version on first boot. From then on you can boot from USB or continue using the Micro SD card.

Where is ________ package?

The Mark II is intended to be a device for consumers. As such we try to keep the system as lean as possible. How lean? Currently it is "no-installed-text-editor" lean!

The mycroft container however is based on Ubuntu 20.04 so all of your standard tooling is available via the apt package manager.

Which GPIO pins are available?

The Raspberry Pi GPIO pins 1, 12 and 13 are brought out to J9 on the SJ201. This is next to the volume up button on the front-right of the board if you are looking at the device face on. GPIO pin 0 is also not used.

How do I rotate the screen for my custom case?

You can set the default rotation of your display in this file:

The available options are:

  • NORMAL = Default (0 degrees)

  • CW = Clockwise (90 degrees)

  • CCW = Counterclockwise (90 degrees)

  • UD = Upside down (180 degrees)

The mycroft-gui-mark-2 package must then be recompiled for use.

More questions?

Join us in Mycroft Chat or the Community Forums, we’re happy to answer any other questions you might have.

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