{"title":"Adafruit Grand Central M4 Express featuring SAMD51 - Without Headers","handle":"adafruit-grand-central-m4-express-featuring-samd51-without-headers","url":"/products/adafruit-grand-central-m4-express-featuring-samd51-without-headers","description":"The Adafruit Grand Central M4 Express is a powerful development board built around the Microchip ATSAMD51P20 — a 120 MHz Cortex M4 processor with hardware floating point, 1 MB Flash, and 256 KB RAM. In the familiar Arduino Mega form factor, it brings 70 GPIO pins, dual DACs, 15 analog inputs, 8 MB QSPI Flash, an SD card slot, and a NeoPixel to your projects.\n\nThis headerless version ships without through-hole components soldered, making it ideal for direct soldering into custom builds or fitting into tight spaces. It supports both CircuitPython and Arduino IDE, with a UF2 bootloader for drag-and-drop firmware loading over USB.\n\nKey Features\n\n\nATSAMD51P20 Cortex M4 at 120 MHz – Hardware DSP and floating point support\n\n1 MB Flash, 256 KB RAM – 32-bit, 3.3V logic and power\n\n70 GPIO Pins Total – 62 accessible GPIO, 16 analog inputs, 2 true analog outputs (DAC)\n\n8 Hardware SERCOM – Configurable as I²C, SPI, or UART\n\n22 PWM Outputs – For servos, LEDs, and motor control\n\nStereo I²S Input/Output – With MCK pin for audio projects\n\n12-bit Parallel Capture Controller – For camera and video input\n\nBuilt-in Crypto Engines – AES-256, true RNG, and public key controller\n\n8 MB QSPI Flash – Acts as storage for CircuitPython scripts and files, or as a datalogger in Arduino\n\nMicro SD Card Slot – Removable storage via SPI\n\nNative USB – Serial, HID keyboard/mouse, and UF2 bootloader for drag-and-drop programming\n\nFlexible Power – 7–9V DC via 2.1 mm jack (with on/off switch) or 5V via Micro-USB, with automatic switching\n\nStatus LEDs and NeoPixel – Green power LED, RX/TX LEDs, red indicator LED, and one RGB NeoPixel\n\n\nIdeal For\n\nComplex projects needing many I/O pins (Arduino Mega replacement)\nCircuitPython development with high performance and large storage\nAudio, sensor logging, and data-heavy applications\nCustom builds requiring a low-profile, headerless board\n\n\nPackage Contents\n\n1× Adafruit Grand Central M4 Express (without headers) – Assembled and tested\n1× 2.1 mm DC jack (loose, unsoldered)\nBumper feet\n\n\n\nNote: This is the headerless version — no through-hole headers are soldered. The front half shares the same shape and pinout as Adafruit Metro boards, so it is compatible with Metro/Arduino shields.\n\n\nResources\n\nAdafruit Grand Central M4 Learn Guide\nUF2 Bootloader Guide\nCircuitPython\n","vendor":"Adafruit","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":5321,"title":"Default Title","sku":"AF-4084","price":61.92,"compare_at_price":0.0,"on_sale":false,"in_stock":true,"available_quantity":10,"option1":"Default Title"}]}