Teensy 3.1 is a small, breadboard-friendly development board designed by Paul Stoffregen and PJRC. Teensy 3.1 brings a low-cost 32 bit ARM Cortex-M4 platform to hobbyists, students and engineers, using an adapted version of the Arduino IDE (Teensyduino) or programming directly in C language. Teensy 3.1 is an upgrade over 3.0: now with 64K of RAM, 256K of Flash, 5V tolerant digital inputs, 12 bit DAC, dual ADC, and CAN bus support. Teensy 3.1 is a drop-in replacement upgrade for 3.0 and can run any sketches designed for 3.0.