In the past few years, we have covered plenty of fun Teensy 3.x projects. The Teensy 4.0 is now here. It is a fast microcontroller with an ARM Cortex-M7 processor at 600MHz. It is the same size as Teensy 3.2 and works with all the functions on it.
Teensy 4.0 offers dynamic clock scaling and power shut off capability. It features 2 USB ports, 40 digital pins, and 31 PWM pins.