SPECIFICATIONS

Brand Name: RAK

High-concerned chemical: none

Model: RAK6421

Origin: Mainland China

Type: Raspberry pi

Type 1: WisBlock Pi HAT Only

Type 2: Starter Kit Environment 1 (Basic) -Temp/Humidity/Pressure/VOC/UV/RTC

Type 3: Starter Kit Environment 2 (Advanced) -Temp/Humidity/Pressure/CO2/VOC/UV/RTC

Type 4:  Starter Kit Industrial -RTC/Buzzer/RS485/4-20mA

What is WisBlock HAT for Raspberry Pi RAK6421?

RAK6421 is a powerful Raspberry Pi HAT that lets you connect WisBlock modules directly to any Pi (Pi 4, Pi 5, or Pi Zero 2W). Whether you're building a Meshtastic router, a sensor gateway, or a LoRa test platform, RAK6421 makes it easy to integrate LoRa radios, GPS, environmental sensors, and more, all in a modular, plug-and-play way.The RAK6421 is compatible with the HAT+ specification by using an independent EEPROM for metadata and device tree information

RAK6421 is also compatible with our RAK7391 WisGate Connect and our RAKR314 CM4 carrier board, both based on CM4.

Why You Need WisBlock HAT for Raspberry Pi RAK6421

Turn your Raspberry Pi into a powerful IoT hub with the RAK6421 WisBlock Adapter. It lets you plug in pretty much any WisBlock sensor or interface module, from LoRa radios to GPS and environmental sensors, directly onto your Pi. No extra baseboard needed. Perfect for rapid prototyping, smart monitoring, or building a compact Meshtastic node.

Why it's useful:

• Connect WisBlock modules instantly – No need for a separate WisBlock baseboard

• Supports sensors, radios, and GPS – Easily build LoRa or sensor-based applications

• A Great IoT and Meshtastic Pi HAT – Ideal for long-range communication and logging

• Compact and plug-and-play – Clean setup, fast integration, no soldering required

Key Features of RAK6421 WisBlock Pi HAT for Raspberry Pi

• Standard 40-pin Raspberry Pi Header

• 2 WisBlock IO slots + 4 WisBlock Sensor slots

• Supports LoRa radios, I2C sensors, GPS, I2S audio

• Built-in I²C ADC for analog input (e.g., temperature, light)

• Powers modules via 3.3V and VBAT from Pi’s 5V rail

• Compatible with RAK13300 and RAK13302 LoRa radios

• Add-on options: Raspberry Pi, enclosure, and sensor bundles

• On-boardEEPROM connected to ID_SA and ID_SC signals

Key Benefits of WisBlock HAT for Raspberry Pi RAK6421

RAK6421 key benefits are:

• Simplifies hardware assembly: no extra adapters, no flying cables

• Allows to use different hardware in a compact and standardized way

• Allows hardware re-use across different applications

• Supports HAT+ specification for hardware auto-discovery by the OS

Use Case #1

To monitor air quality remotely, an engineer builds a Pi-based sensor logger with MQTT output using RAK6421 LoRa Expansion Board for Pi. It seamlessly connects WisBlock sensors into a compact weather or pollution station.

Use Case #2

A research team deploys a Pi-based LoRa communication hub in a remote farm. RAK6421 helps them quickly connect long-range radios and sensors for agriculture data collection without extra hardware.

What Can You Connect？

The RAK6421 is compatible with many existing WisBlock modules and it will be with more to come. The list below does not include all the modules you can use with the RAK6421 but it can help you get an idea of what you can build with it. 

Note：That some GPIOs are shared between slots in the RAK6421, double check the configuration you plan to use for potential conflicts.

• Wireless communications

  • RAK13300 WisBlock LPWAN Module (LoRa/LoRaWAN)

  • RAK13302 WisBlock High Power (1W) LPWAN Module (LoRa/LoRaWAN)

  • RAK13600 WisBlock NFC Reader Module

• RTC

  • RAK12002 WisBlock RTC Module
    

• GPS

  • RAK12500 WisBlock GNSS Location Module based on u-blox ZOE-M8Q

  • RAK12501 WisBlock GNSS GPS Location Module based on Quectel L76K

• Sensors

  • RAK1901 WisBlock Temperature and Humidity Sensor
    

  • RAK1902 WisBlock Barometer Pressure Sensor Module
    

  • RAK1903 WisBlock Ambient Light Sensor Module

  • RAK1906 WisBlock Environmental Sensor Module

  • RAK12004 WisBlock MQ2 Gas Sensor Module

  • RAK12006 WisBlock PIR Sensor Module

  • RAK12009 WisBlock MQ3 Alcohol Gas Sensor Module

  • RAK12013 WisBlock Radar Sensor Module

  • RAK12015 WisBlock Vibration Detection Sensor Module

  • RAK12019 WisBlock UV Sensor

  • RAK12037 WisBlock CO2 Sensor Module

  • RAK16000 WisBlock DC Current Module

• IO Modules

  • RAK5801 WisBlock 4-20 mA Interface Module

  • RAK5802 WisBlock RS485 Interface Module

  • RAK5811 WisBlock 0-5 V Interface Module

  • RAK13001 WisBlock Relay IO Module(30V 2A)

  • RAK13002 WisBlock IO Module

  • RAK13003 WisBlock IO Expansion Module

  • RAK13004 WisBlock PWM Expander Module

  • RAK13005 WisBlock LIN Module

  • RAK13006 WisBlock CAN Bus Module

  • RAK13007 WisBlock Relay Module (250V 5A)

  • RAK14006 WisBlock Rotary Encoder Module

  • RAK16001 WisBlock ADC Module

  • RAK17000 WisBlock Motor Control Module

• Human Interface

  • RAK1921 WisBlock OLED Display

  • RAK12001 WisBlock Fingerprint Sensor Module

  • RAK18001 WisBlock Buzzer Module

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Note：Not all the Sensor modules are supported by Meshtastic.

Meshtastic supported modules:

What’s in the Box

• WisBlock Pi HAT Only

  • 1 pc RAK6421 Pi HAT 

  • 1 set Screw

• Starter Kit Environment 1 (Basic)
  

  • 1 pc RAK6421 Pi HAT Kit

  • 1 pc VOC Sensor RAK12047

  • 1 pc Environment Sensor RAK1906

  • 1 pc RTC Sensor RAK12002

  • 1 pc UV Light Sensor RAK12019
    

  • 1 set Screw

• Starter Kit Environment 2 (Advanced)
  

  • 1 pc RAK6421 Pi HAT Kit

  • 1 pc VOC Sensor RAK12047

  • 1 pc Environment Sensor RAK1906

  • 1 pc RTC Sensor RAK12002

  • 1 pc UV Light Sensor RAK12019

  • 1 pc CO2 Sensor RAK12037

  • 1 set Screw

• Starter Kit Industrial
  

  • 1 pc RAK6421 Pi HAT Kit

  • 1 pc RTC Sensor RAK12002

  • 1 pc Buzzer Sensor RAK18001

  • 1 pc 4-20mA Module RAK5801

  • 1 pc RS485 Module RAK5802

  • 1 set Screw

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How to Get Started with WisBlock HAT for Raspberry Pi RAK6421

• Overview of RAK6421 WisBlock Pi Hat

• Datasheet for RAK6421 WisBlock Pi Hat

• Kit for RAK6421 WisBlock Pi Hat

Please contact customer service to receive the above documents.