It's Here! Chris Odom's Physical Computing & Robotics with the Arduino IDE - Volume Two!

Teensy 3.5

$24.25

Version 3.5 features a 32 bit 120 MHz ARM Cortex-M4 processor with floating point unit. All digital pins are 5 volt tolerant.

All Teensy boards are shipped assembled and fully tested.

Motherboard kit can be found here