KIISU V4B - Flipper Zero alternative

KIISU V4B: a Flipper Zero alternative in a card format

KIISU V4B is an open-source development board with Flipper Zero functions, packed into a credit-card format. Two STM32 microcontrollers, a full radio path, sensors, USB-C, microSD and a replaceable cell. The GPIO pinout is 1:1 with Flipper, so boards and accessories from the Flipper community work without modification.

The hardware is designed by RainWalker OÜ in Estonia. SAPSAN is the official distributor in Poland: shipped from our warehouse, no customs, local warranty.

What KIISU V4B can do

• SubGHz CC1101 (300-348 / 387-464 / 779-928 MHz) with an external antenna option
• NFC ST25R3916: ISO 14443A/B, FeliCa, MIFARE
• 125 kHz RFID: read, write and emulate (EM4100, HID, pet tags)
• IR: receiver and transmitter for TV, air-conditioning, projector and smart-home remotes
• Bluetooth Low Energy: sniffing and emulation
• iButton 1-Wire (Dallas DS1990)
• 2 × 9 GPIO pins compatible with Flipper Zero

Sensors on board: an accelerometer with a magnetometer, a temperature and humidity sensor and an ambient light sensor. Footprints for a BME680 and a VL53xxx rangefinder are ready for your own soldering.

KIISU vs Flipper Zero

KIISU runs the same firmware as Flipper Zero and takes the same GPIO boards, so you carry over tools, apps and guides without relearning anything. On top of that you get a second, faster microcontroller and a card format that fits in a wallet. What you give up is a ready enclosure: KIISU is a board, you print an enclosure from community models or carry it like a card.

If you want a device that works straight out of the box, choose Flipper Zero. If you prefer open hardware, more power and a lower price, choose KIISU.

KIISU firmware: Momentum, Unleashed, RogueMaster

The official KIISU firmware is recommended. Stock Flipper Zero firmware and the popular forks also work: Momentum, Unleashed, RogueMaster, Xtreme. The auxiliary MCU runs its own firmware independently of the main one, so heavier tasks do not block the interface.

• github.com/kiisu-io/kiisu-firmware - main MCU firmware
• github.com/kiisu-io/kiisu4-companion-fw - auxiliary MCU firmware
• github.com/kiisu-io/kiisu4 - schematics, BOM, PCB

GPIO compatible with Flipper Zero: Feberis Pro and MAXIMUS

The 2 × 9 pin header has the same layout as on Flipper Zero, so expansion boards from the Flipper ecosystem work on KIISU without modification. At SAPSAN you can pair it with Feberis Pro (SubGHz + NRF24 + WiFi) and MAXIMUS CC1101, a SubGHz amplifier.

• Feberis Pro - SubGHz, NRF24 and WiFi expansion board
• MAXIMUS CC1101 - SubGHz amplifier

KIISU enclosure and community accessories

We sell KIISU as a board. Enclosures, keychains and stands are printed from ready community models, and firmware forks and fixes land on the kiisu-io GitHub. The box includes a 3D-printed keychain with the KIISU logo.

• GitHub kiisu-io - code, issues, pull requests
• Makerworld: KIISU collection - enclosures, keychains and stands for 3D printing
• Printables: KIISU models - 3D-printable models

KIISU in your wallet, uConsole in your backpack

HID, RF and NFC in your pocket, and Linux with a keyboard next to it: KIISU and uConsole together make a mobile pentester's lab. See the uConsole Kit RPI-CM4 Lite.

• uConsole Kit RPI-CM4 Lite - a modular cyberdeck running Linux