What's smaller than a Feather but larger than a Trinket? It's an Adafruit ItsyBitsy M4 Express featuring the Microchip ATSAMD51! Small, powerful, with an ultra-fast ATSAMD51 Cortex M4 processor running at 120 MHz - this microcontroller board is perfect when you want something very compact, with a ton of horsepower, and a bunch of pins. This Itsy is like a bullet train, with its 120MHz Cortex M4 with floating point support and 512KB Flash and 192KB RAM. Your code will zig and zag and zoom, and with a bunch of extra peripherals for support, this will for sure be your favorite new chipset.

ItsyBitsy M4 Express is only is only 1.4" long by 0.7" wide but has 6 power pins, 23 digital GPIO pins (7 of which can be analog in, 2 x 1 MSPS analog out DACs, and 18 x PWM out). It's the same chip as the Adafruit Metro M4 but really really small. So it's great once you've finished up a prototype on a Metro M4 or (the upcoming) Feather M4, and want to make the project much smaller. It even comes with 2MB of SPI Flash built in, for data logging, file storage, or CircuitPython code.

The most exciting part of the ItsyBitsy M4 is that while you can use it with the Arduino IDE, it ships it with CircuitPython on board. When you plug it in, it will show up as a very small disk drive with main.py on it. Edit main.py with your favorite text editor to build your project using Python, the most popular programming language. No installs, IDE or compiler needed, so you can use it on any computer, even ChromeBooks or computers you can't install software on. When you're done, unplug the Itsy' and your code will go with you.

Same size, form-factor as the ItsyBitsy 32u4 and ItsyBitsy M0, and nearly-identical pinout as both

ATSAMD51 32-bit Cortex M4 core running at 120 MHz

Hardware DSP and floating point support

512 KB flash, 192 KB RAM

2 MB SPI FLASH chip for storing files and CircuitPython code storage.

32-bit, 3.3V logic, and power

Tons of GPIO! 23 x GPIO pins with following capabilities:

• Dual 1 MSPS 12 bit true analog DAC (A0 and A1) - can be used to play 12-bit stereo audio clips
• Dual 1 MSPS 12 bit ADC (7 analog pins some on ADC1 and some on ADC2)
• 6 x hardware SERCOM - Native hardware SPI, I2C and Serial all available
• 18 x PWM outputs - for servos, LEDs, etc
• No I2S. We have no idea why but I2S is only supported on the 64 pin version of this chip and we could only fit the 48 pin version. But there's a stereo DAC you could use?
• 8-bit Parallel capture controller (for camera/video in)
• 1 x Special Vhigh output pin gives you the higher voltage from VBAT or VUSB, for driving NeoPixels, servos, and other 5V-logic devices. Digital 5 level-shifted output for high-voltage logic level output.