Cardputer Just Became A Flipper Zero Rival, And Its Expansion Bus Explains Why

This little pocket computer used to be a curious hobbyist toy. Now it is an obvious threat to much more expensive niche gadgets and a clear invitation to tinkerers who like to push radio and network limits.

M5Stack has released an updated Cardputer that keeps the tiny keyboard and screen but adds a proper expansion bus on the back. Stick a LoRa and a GPS module on it, and you get a standalone Meshtastic node with a keyboard. Load the right firmware, and the same device becomes a compact pen testing and network utility platform. That combination is what makes this update interesting right now.

Why The Expansion Bus Is A Quiet Big Deal

The original Cardputer was charming because it packed a battery, microphone, speaker, SD card reader, and even an infrared emitter into a credit card-sized board with magnets on the back. Its brain is a removable ESP32 module, which gives it Wi Fi and Bluetooth and makes it easy to reprogram.

What it did not have was a clean way to attach the kinds of radio modules hobbyists demand for off-grid messaging and signal work. People hacked around that limitation by using awkward SD card interfaces or by disassembling and soldering to the board. That always felt like defeating the purpose of a neat pocket machine.

The new Cardputer fixes that with an expansion connector on the back. The first module available for it is a LoRa and GPS combo that snaps into place and can be secured with screws. That simple design choice changes how people will use the device.

Hardware Changes Worth Paying Attention To

The advanced Cardputer adds a larger battery, a headphone jack, and an inertial measurement unit to help you sense movement. The case now comes in white. Because audio and keyboard handling were updated, older firmware needs to be recompiled or updated to work on this new hardware.

The removable ESP32 remains the central processor, which means the community can continue to build and port firmware. That continuity is why this product attracts a developer ecosystem rather than a closed appliance crowd.

The LoRa And GPS Module

Slotting in a LoRa and GPS module transforms the device from a pocket toy into a proper Meshtastic node. LoRa stands for long-range and is a license-free, low-power digital radio technology. Couple LoRa with GPS, and you have location-aware nodes that can form a mesh when they are within radio range of each other.

What You Gain And What You Lose

The module tilts the Cardputer upwards because it extends beyond the back. That makes the fitted device less pocketable than the original slim shape. A slimmer, inline module would have been nicer, but the snap fit is practical and fast to install.

Meshtastic On A Pocket Keyboard

Meshtastic is an open-source off-grid messaging protocol that runs on cheap LoRa radios. Most Meshtastic devices are headless and use a phone via Bluetooth as the user interface. The Cardputer flips that script by letting you use a real keyboard and a screen without a phone in the loop.

Installing Meshtastic is straightforward with M5 Burner. Connect the Cardputer to a computer over USB-C, select the Cardputer in the interface, and flash the Meshtastic image. After boot, you choose the regional frequency. For Europe, that is 868 MHz, which the Cardputer will configure.

The stock green text Meshtastic interface included with the release is called Base UI. It is functional but rough around the edges. Typing can feel sluggish because the software’s response lags, and incoming messages do not get stored in a history. If a new message arrives while you are reading another one, then the previous message is lost.

If you want a smoother standalone Meshtastic interface, the graphical MUI is preferable. Devices like the Lilygo T Deck Plus run the MUI, which supports message history and map views of nearby nodes. The Cardputer can be configured to use better interfaces as they are ported to the new hardware.

Evil Cardputer And Pen Testing Utilities

Beyond mesh messaging, the Cardputer becomes a tiny but capable pen testing platform when loaded with the Evil Cardputer firmware. This variant comes from the Evil M5 project and is tailored for M5Stack hardware.

To unlock the full feature set, you need to copy an SD card files folder into a specific Evil folder on a micro SD card. The firmware then exposes a broad set of network tools built around the ESP32 and the available radios.

What The Toolkit Can Do

The toolset includes classic wireless testing capabilities such as creating captive portals, performing deauthentication operations, and collecting Wi Fi handshakes for offline analysis. When used on a network, it also supports DHCP and DNS manipulation, rogue DHCP servers, and responder-style sniffing tools.

There are more advanced network-oriented tools, too. The firmware can perform IP and port scans, act as an SSH client, and be configured to establish a reverse TCP tunnel back to a command and control server that you manage. It also contains utilities to detect insecure printers, find networked CCTV cameras, and even detect other hobby devices like Flipper Zeros and Ponegotchi units.

These features make the Cardputer a practical learning device for system administrators and students who want hands-on experience diagnosing network vulnerabilities. The firmware author explicitly warns against using the tools on networks you do not own or have permission to test.

Installing Firmware Without A Computer

M5Stack provides two main ways to flash firmware. M5 Burner is the desktop tool that you use over USB-C. The other is M5 Launcher, which acts as an on-device bootloader and lets you download firmware over Wi Fi.

Install the launcher, and each time the Cardputer boots, you will briefly see a green launcher prompt. Press the OK button and choose the over-the-air option. Log into local Wi Fi, and you will be presented with available firmware images that can be installed directly or saved to the SD card for later.

Not every piece of software is yet compatible with the new Cardputer hardware. Some projects need updates to match the revised audio and keyboard wiring. For certain applications, like Doom, you must pick the correct partition in the launcher settings for the game to run properly.

Where This Fits In The Pocket Gadget Landscape

The Cardputer advanced has an odd position. It is not trying to be a polished consumption device. It is a platform for experimentation where the hardware is deliberately open and the firmware scene moves fast. That makes it attractive to the crowd that loves the Flipper Zero and wants something that can complement or extend that device, rather than directly replace a single-purpose tool.

Because it is so inexpensive and because it uses standard ESP32 hardware, developers are willing to treat it as a sandbox. New modules such as LoRa, GPS, and potentially a CC1101 for sub-gigahertz work make it useful for both off-grid messaging and radio-related exploration.

The community around M5Stack has already produced several firmware families that give the Cardputer distinct personalities. There is the minimalist Meshtastic base, the polished MUI for graphical use, and the more aggressive Evil Cardputer for security research. That range is a strength because it lets users pick the compromise they want between safety and capability.

Practical Use Cases

Think about scenarios where a cheap keyboarded LoRa node matters. Search and rescue teams or outdoor groups could use a fleet of Cardputers running Meshtastic to share short messages and location without any cellular infrastructure. Home labbers and network admins can use Evil Cardputer on a closed test network to learn about DHCP and DNS weaknesses. Tinkerers will mix and match features to fit creative projects.

None of this makes the Cardputer a mainstream consumer gadget. It does make it one of the most interesting affordable tools for people who like to build and break networks and radios in real-world conditions.

There will be friction. The new hardware changes mean older firmware needs attention to work properly. The LoRa Base UI has clear limitations that will need iterative improvements. But the expansion bus invites a pace of modular innovation that a fixed design cannot match.

Expect the obvious next step to be a CC1101 module that opens up sub-gigahertz experimentation similar to what the Flipper Zero offers. There are already firmware projects that implement that kind of functionality on other M5Stack devices, so a port to the Cardputer is likely to follow.

The Cardputer Advanced is not just another novelty device. It is a credible, low cost platform that folds mesh radios, GPS and security focused firmware into a pocketable toolkit. That combination will influence how hobbyists and professionals think about cheap handheld radios and tiny pen testing rigs in the months to come.

Keep an eye on the expansion bus. The modules developers choose to build for it will say more about the direction of this ecosystem than any single spec sheet. If you care about off-grid communication or hands-on network security practice, this is the little device worth watching and testing further.

Related reading: Check community firmware repositories and the Meshtastic project for details on protocols and compatibility as the Cardputer hardware evolves.

Where the expansion bus leads next will tell us whether the Cardputer becomes an indispensable toolbox for field work or a clever footnote in the history of pocket tinkering.