MATERIALS: The first prototype was made of Lego bricks, fishing wire, surgical tubing for fingers, and five independently-controlled servos. It is now made of metal. Version 3.1 is made with gold plating for easier smoldering. Version 3.0 has a tin plating finish and Version 3.2 has a dedicated 3.3V regulator.
POWER: Microcontrollers. Teensy 3.2 & 3.1 have a proper analog output. Filter PWM, but true analog output responds rapidly. The output is created by the stable reference voltage, so it's doesn't vary if your power supply voltage changes slightly.
COLOR: The color of Teensy 3.1 was changed from black to green on January 22, 2014.
FEATURES: Versions 3.2 and 3.1 have the same size, shape, and pinout. Teensy 3.2 adds a more powerful 3.3 volt regulator, with the ability to directly power ESP8266 Wifi, WIZ820io Ethernet and other power-hungry 3.3 volt add-on boards. The RAM has quadrupled since 3.0, from 16K to 64K. While 16K is plenty for nearly all Arduino libraries, 64K allows for more advanced applications. Icons and graphics for color displays and audio effects requiring delays, like reverb and chorus, will become possible on Teensy 3.2 & 3.1. The maximum speed is only 48 MHz, and the Cortex-M0+ omits M4's special math instructions. Teensy-LC has only 4 lightweight DMA channels, rather than 16 fully featured channels. Fewer hardware timers are available. ARM Cortex-M0+ processor at 48 MHz, 62K Flash, 8K RAM, 12 bit analog input & output, hardware Serial, SPI & I2C, USB, and a total of 27 I/O pins. Teensy-LC provides a 5V output to directly drive WS2812/NeoPixel LEDs. A 74LV1T125 buffer is connected to pin 17, with the increased output voltage available on another pin. Teensy-LC maintains the same form-factor as Teensy 3.1, with most pins offering similar peripheral features.
COMPATABILITY: Versions 3.2 and 3.1 are written for Teensy 3.0 on the Arduino IDE using Teensyduino software. The hardware is intolerant of I/O pins. Teensy-LC supports USB Serial, MIDI, Keyboard (international layouts), Mouse, Joystick, and RawHID protocols. A full set of 16 bidirectional USB endpoints are supported by the hardware, allowing any type of USB device. Many Arduino libraries require a hardware timer. Traditional Arduino products have 3 or 4 timers, with only 1 or 2 providing more than 8 bit resolution. Teensy-LC has a total of 7 timers, all of them with 16 or more bits of resolution, to allow excellent compatibility with easy-to-use libraries. Many combinations of popular libraries, which would normally conflict, can seamlessly run together on Teensy LC and Teensy 3.1. Teensy-LC provide plenty of serial connectivity: 2 SPI ports, 2 I2C, and 3 Serial ports. All 3 serial ports are supported by high quality drivers in Teensyduino, with both transmit and receive buffering, and even support for RS485 transmitter enable. Analog signals are critically important to many projects. Teensy-LC has 13 pins than can function as analog inputs. The effective analog resolution is 12 bits. It also has a true 12 bit digital to analog converter, for an analog output signal.