SharkDeck by M5Shark

SharkDeck Documentation

Setup, Linux workflows, firmware recovery, GPIO expansion, and safe operating guidance for the SharkDeck portable Linux terminal.

Revision 4Updated 2026-08-19

How to log in

Default login for the official image (pi / pi).

The official SharkDeck image boots to a normal Linux login prompt. Default credentials for the official image are username pi and password pi. If your image documentation states different credentials, use the documented ones for that image.

What is SharkDeck?

A compact, terminal-first Linux computer for development, learning, and maker projects.

SharkDeck is designed for developers, makers, Linux learners, scripting, remote administration, and GPIO prototyping. It uses a microSD card for its Linux system and storage.

Hardware specifications

Gen 1 hardware details for the SharkDeck.

  • Processor / SBC: WalnutPi Zero 2W with an Allwinner H618 SoC.
  • CPU: Quad-core ARM Cortex-A53, up to approximately 1.5 GHz.
  • RAM: 1 GB DDR3 on the standard configuration.
  • Display: 3.5-inch color display at 480 x 320 resolution.
  • Storage: microSD card (required for the operating system).
  • Connectivity: Wi-Fi, Bluetooth, Ethernet, USB, and USB-C power.
  • Expansion: 40-pin GPIO header.
  • Power: integrated UPS board with rechargeable lithium battery support.

What SharkDeck is not

Important distinctions about built-in capabilities.

SharkDeck is a portable Linux computer. It does NOT include built-in CC1101, NRF24, Sub-GHz radio, NFC, RFID, or infrared transmit/receive hardware. External modules can be connected separately when supported by your Linux and GPIO setup.

SharkDeck is not a laptop replacement and may not include a desktop interface by default. It is not a Flipper Zero and does not include built-in RF modules unless explicitly documented for a specific model.

Before you start

  • Use a compatible, reliable microSD card (8GB or larger is recommended) with the correct SharkDeck system image.
  • Download the current official WalnutPi Zero 2W image from the SharkDeck firmware page (sharkdeck.dev/firmware).
  • Use a stable power supply and cable appropriate for the device.
  • Back up important files before changing or reflashing the operating system.
  • Keep the device ventilated during installation and sustained workloads.

microSD card is required

SharkDeck boots its operating system from microSD.

The microSD card is required for the Linux operating system and storage. A SharkDeck ordered WITHOUT an SD card does not arrive with the OS already available on internal storage. You must provide a compatible microSD card and install the required SharkDeck image before the device can boot.

Installing the SharkDeck OS

Prepare a microSD card with the official image.

  1. Obtain a compatible microSD card (8GB or larger is recommended).
  2. Download the current SharkDeck-compatible OS image from the official source only: https://sharkdeck.dev/firmware (the official WalnutPi Zero 2W image, provided as a .zip).
  3. Insert the microSD card into a computer.
  4. Flash the image to the SD card with an imaging utility. Do NOT simply copy the .img file onto the card; an OS disk image must be written to the entire card.
  5. Verify the published SHA-256 checksum before writing the image.
  6. Safely eject the microSD card.
  7. Insert it into SharkDeck while SharkDeck is powered OFF.
  8. Connect stable USB-C power and power the device on.
  9. Allow extra time for the first boot.

First boot

  1. Insert the prepared microSD card while the device is powered off.
  2. Connect the supported power source and wait for the Linux system to start.
  3. Complete any image-specific account, network, or locale setup.
  4. Install system updates only after confirming the image and storage are working correctly.
uname -a
cat /etc/os-release
df -h

Power and microSD storage

Linux writes data to the microSD card during normal operation. Shut down cleanly before removing power to reduce the chance of filesystem corruption.

sudo shutdown -h now

SSH and terminal tools

SharkDeck supports common Linux terminal workflows. Available packages depend on the installed Linux image and its package repositories.

hostname -I
ip addr
ssh user@device-ip
python3 --version
git --version
node --version

Installing software packages

Package management on Debian-based images.

sudo apt update
sudo apt install PACKAGE

Not every package is available on every SharkDeck image. The CPU architecture is ARM64/AArch64, so software that requires x86/x86_64 may not run natively.

For Python work, prefer virtual environments when appropriate. For Git, help with authentication and normal development workflows as needed.

Docker

Running containers on SharkDeck.

SharkDeck documentation describes Docker support. However, architecture matters, RAM is limited, and storage is SD-based. Not every container has ARM64 builds.

docker run --rm hello-world

GPIO expansion

GPIO can be used with compatible external modules for maker projects. External RF modules and other accessories are not built in unless the product listing explicitly says otherwise.

  • Confirm pin numbering, voltage, and ground before connecting hardware. Raspberry Pi GPIO pin numbering does NOT apply; use the SharkDeck/WalnutPi-specific mapping.
  • Power off before changing wiring.
  • Use current limiting and level shifting where required.
  • Never randomly connect 5V to GPIO signal pins.
  • Test with simple, authorized hardware workflows first.

Wi-Fi troubleshooting

Steps when Wi-Fi does not work.

  1. Confirm Linux boots normally and Wi-Fi is visible.
  2. Check whether SharkDeck can see any networks, or if only one network is missing.
  3. Verify the password and try to forget and reconnect the network.
  4. Try another access point or hotspot.
  5. Reboot the networking service or the device.
ip addr
ip link
nmcli device
nmcli device wifi list
rfkill list
dmesg

Bluetooth troubleshooting

Steps when Bluetooth does not work.

rfkill list
systemctl status bluetooth
sudo systemctl enable --now bluetooth

Verify Bluetooth hardware is visible after enabling the service. Not every OS image ships with exactly the same Bluetooth packages.

Ethernet troubleshooting

Steps when Ethernet does not work.

  1. Check the cable first.
  2. Inspect the interface with ip addr and ip link.
  3. If the interface exists but has no address, check the network configuration and DHCP.
  4. Try another Ethernet cable and another router or switch port.
ip addr
ip link

Keyboard troubleshooting

Steps when the keyboard does not work.

Determine whether the entire keyboard is dead, only certain keys fail, the keyboard works during boot but not in Linux, or the keyboard stopped working after an OS change.

lsusb

USB devices

Troubleshooting USB peripherals.

lsusb
dmesg
  • Disconnect and reconnect the USB device, then check recent kernel messages.
  • Try another USB device, cable, or adapter.
  • Remove unnecessary peripherals.
  • Remember portable boards have power limits. High-current USB devices may require externally powered hardware.

Battery and UPS

Battery behavior and troubleshooting.

SharkDeck includes an integrated UPS design with rechargeable battery support. Confirm whether a battery is installed in the specific unit before troubleshooting.

  • Does SharkDeck work with USB-C connected?
  • Does it shut down immediately when USB-C is removed?
  • Does a charging indicator appear?
  • How long has it been charging?

Device does not turn on

Power troubleshooting order.

  1. Test with a known-good USB-C cable.
  2. Test with a known-good power adapter.
  3. Allow charging time if the unit is battery-equipped.
  4. Check the power indicator.
  5. Try powering with and without the SD card to observe indicators.
  6. If there is still no power indication with known-good external power, request a startup video and escalate for hardware review.

Black screen troubleshooting

Screen is black, device powers on.

  1. Power: confirm the power indicator appears, the charging indicator appears, the device reacts to the power button, and USB-C power is connected.
  2. microSD: verify a properly flashed SharkDeck-compatible SD card is installed.
  3. Power supply: use stable USB-C power. Try another known-good cable and another suitable adapter.
  4. SD card: power off, remove the SD card, reinsert it fully, and retry.
  5. Reflash: if necessary, reflash the current official SharkDeck image.
  6. Different SD card: try another known-good microSD card.
  7. Video: if the screen is still black, send a short video from power-off through startup, including the screen and power indicators.

Stuck on logo, boot loop, or no SD detected

Boot-stage troubleshooting.

If SharkDeck displays a logo but does not reach Linux, possible causes include a corrupted filesystem, incomplete image, failing SD card, incompatible OS image, power instability, or a Linux boot configuration problem.

  1. Wait several minutes on first boot.
  2. Power off safely if possible.
  3. Reseat the SD card.
  4. Retry with stable USB power.
  5. Reflash the official image.
  6. Try another SD card.

Boot loop symptoms: the device starts, the logo appears, it restarts, and the cycle repeats. First test with stable external USB-C power. If the problem disappears when externally powered, investigate the battery, UPS, or power delivery. If it continues, remove unnecessary USB peripherals and GPIO modules, check the SD card, reflash the OS, and test another SD card.

If the card is not detected: power OFF before removing or reinserting it. Check that the card is fully inserted, the correct image was used, the card was actually flashed rather than file-copied, the write completed successfully, and the card is not corrupted. Try another known-good microSD.

Corrupted OS and recovery

Symptoms and recommended recovery.

Corruption symptoms may include filesystem errors, boot failures, random Linux errors, missing system files, a device that worked before but stopped booting, or problems after an unsafe shutdown. The recommended recovery is to reflash the official SharkDeck image.

Device worked until the OS was changed

Restore the compatible image first.

If the device worked before another OS was installed, prioritize OS recovery instead of hardware diagnosis. Installing another OS usually does not damage the hardware. Restore the correct SharkDeck image to the microSD card first.

The same applies to display problems such as a rotated screen, wrong resolution, oversized text, or an image outside the screen. Remember the native display specification is 480 x 320. If the problem appeared after installing a different Linux image, suspect display configuration or image compatibility, and restore the SharkDeck-compatible image before changing random kernel or display settings.

Storage full and slow performance

Check storage and memory usage.

df -h
free -h
top
htop

Potential causes of slowness include RAM pressure, swap, a slow or failing SD card, background services, heavy Docker containers, browser workloads, or insufficient free storage. Clean package caches and logs only when appropriate, and never delete system files blindly. Normal hardware limitations of the standard 1GB configuration are not defects.

Heat and safety

When to stop using the device.

Some warmth during operation can be normal for SBC hardware. If you notice extreme heat, a burning smell, smoke, battery swelling, or enclosure deformation, disconnect power and stop using the device immediately.

Firmware and recovery

  1. Download the current firmware from the official SharkDeck firmware page (sharkdeck.dev/firmware).
  2. Verify the published SHA-256 checksum before writing the image.
  3. Back up the existing microSD card when recovery data is needed.
  4. Write the image with a trusted imaging tool such as BalenaEtcher or Raspberry Pi Imager, and allow verification to complete.
  5. Insert the card while powered off, then start the device.
Open firmware downloads

Important notes

  • SharkDeck is not a laptop replacement and may not include a desktop interface by default.
  • It is not a Flipper Zero and does not include built-in RF modules unless explicitly documented for a specific model.
  • Software availability and performance depend on the installed image and hardware resources.
  • Use networking, GPIO, radio accessories, and security tools only for legal and authorized work.
  • Contact support with the order number, device batch, issue description, photos, and terminal error messages when available.