Adafruit
Adafruit Metro M4 Express AirLift (WiFi) - Lite
The Adafruit Metro M4 Express AirLift combines the powerful ATSAMD51J19 ARM Cortex M4 processor with an on-board ESP32 WiFi co-processor — all in the standar...
The Adafruit Metro M4 Express AirLift combines the powerful ATSAMD51J19 ARM Cortex M4 processor with an on-board ESP32 WiFi co-processor — all in the standard Metro/UNO shield-compatible form factor. With 120 MHz clock speed, floating point support, and built-in TLS/SSL for secure connections, this board makes IoT projects fast and straightforward in both CircuitPython and Arduino.
The AirLift ESP32 co-processor handles WiFi communication over SPI, with pre-loaded root certificates and plenty of RAM for socket connections. CircuitPython's built-in JSON parsing and requests-compatible library make secure IoT projects remarkably easy to build.
Key Features
- ATSAMD51J19 Cortex M4 @ 120 MHz – With floating point and DSP instructions
- 512 KB Flash + 192 KB RAM – Ample space for complex applications
- AirLift ESP32 WiFi Co-Processor – TLS/SSL support with pre-loaded root certificates
- Native USB – Serial, HID keyboard/mouse support with no additional hardware
- 2 MB QSPI Flash – On-board storage for CircuitPython scripts or Arduino data logging
- 25 GPIO Pins – 8 analogue inputs, 2 true analogue outputs (DAC), 22 PWM outputs
- 6× Hardware SERCOM – Configurable as I2C, SPI, or UART
- Stereo I2S – Audio input/output with MCK pin
- Built-In Crypto – AES-256, true RNG, and public key controller
- UNO Shield Compatible – Standard Metro form factor
- Flexible Power – 7–9V DC (polarity protected) or Micro USB, with auto-switching and on/off switch
- UF2 Bootloader – Drag-and-drop firmware updates via USB storage mode
- Status LEDs + NeoPixel – Power, RX/TX, red LED, and RGB NeoPixel
- 3.3V Logic – All I/O at 3.3V
Ideal For
- Secure WiFi IoT projects with CircuitPython or Arduino
- Data dashboards and web-connected displays
- Projects needing high-performance processing with wireless connectivity
- Audio projects using I2S and DSP capabilities
Package Contents
- 1× Adafruit Metro M4 Express AirLift (WiFi) - Lite (fully assembled with headers)
Resources
Jargon buster
Plain-language definitions for the technical terms used above.
- Bootloader
- Small starter software on a microcontroller that lets new code be uploaded before the main program runs. Knowing how to enter bootloader mode matters when you need to program the board or recover it after a faulty sketch.
- CircuitPython
- A beginner-friendly version of Python designed to run directly on microcontroller boards. If a product supports CircuitPython, you can often program it by copying code files onto the board rather than setting up a more complex toolchain.
- DAC
- A digital-to-analogue converter turns numbers from the microcontroller into a real analogue voltage. It matters if you want to generate simple waveforms, audio-style signals, or variable control voltages rather than just on/off outputs.
- ESP32
- ESP32 is a family of microcontroller modules with built-in wireless features such as Bluetooth and WiFi. Knowing this product uses an ESP32-based module helps explain how it provides wireless serial communication and firmware update features.
- GPIO
- General-purpose input/output pins are microcontroller pins you can set in software to read signals, switch devices on and off, or connect to peripherals. The number of GPIO pins matters because it limits how many buttons, LEDs, sensors, and other parts you can wire directly to the board.
- Headers
- Rows of metal pins used to plug a module into a breadboard or connect it with jumper wires. Pre-soldered headers make the module easier to use straight away without needing to solder the pins yourself.
- HID
- Human Interface Device is a USB device class used for keyboards, mice, gamepads and similar controls. If a board supports HID over USB, it can act like an input device to a computer without needing a custom driver.
- I2C
- I2C is a two-wire communication bus used by many sensors and small modules. It matters because several I2C devices can share the same two wires, but each device needs a compatible address and your controller must support I2C.
- I2S
- I2S is a digital audio interface used to send sound data between chips, such as from a microcontroller to an audio amplifier or DAC. It matters if your project needs cleaner digital audio output than a basic buzzer or PWM signal can provide.
- IoT
- Short for Internet of Things, meaning physical devices that connect to networks or the internet to send data or be controlled remotely. It matters if you want projects such as connected sensors, remote controls or classroom data-logging activities.
- LED
- A light-emitting diode is a small electronic component that lights up when current flows through it in the correct direction. In this kit, LEDs create the flashing effect, so polarity and correct soldering matter for the project to work.
- native USB
- Native USB means the microcontroller itself handles USB communication, rather than using a separate USB-to-serial chip. This matters for programming, debugging, and projects that need the board to act directly as a USB device.
- NeoPixel
- A type of addressable LED system where colour data is sent along a single digital data line from one LED or controller to the next. Compatibility matters because the timing and signal format must match for the lights or driver board to respond correctly.
- PWM
- Pulse Width Modulation is a way for a digital pin to simulate variable output power by switching on and off very quickly. It matters for controlling things like LED brightness, motor speed, or servo-style signals from a microcontroller pin.
- RAM
- RAM is temporary memory used while a device is running, and its contents are lost when power is removed. A “Run in RAM” mode is useful for testing settings without permanently programming the module, but it may not support every feature.
- RGB
- Short for red, green and blue, usually referring to an LED that can mix those three colours. It matters because controlling an RGB LED teaches how separate outputs combine to create different colours.
- Shield
- An add-on board that plugs into a main controller board to give it extra features such as sensing, motor control or communication. Knowing a product supports shields helps you judge whether it can connect neatly into an existing maker-board setup.
- SPI
- A fast serial communication bus often used for displays, memory cards, and sensors. It matters because SPI devices need specific pins for clock and data, plus a separate chip-select line for each device.
- UART
- UART is a simple serial connection that sends data over separate transmit and receive wires, often labelled TX and RX. It matters because this module is designed to replace a wired UART cable with a wireless link while keeping the same serial data format.
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Brands
Connectivity
Microcontrollers
Related Tutorials
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