Editing Teensy (section)

==Variants==
===AVR-based ===
[[File:8-bit teensy.jpg|250px|thumb|right|Teensy 2.0 (above) and Teensy++ 2.0 (below)]]
The ''Teensy 2.0'' sports a AVR ATMEGA32U4 8-bit microcontroller ("µC"), 16 MHz clock (16 MIPS), 25 I/O lines and a USB client port.
There is also a larger variant: the ''Teensy++ 2.0'' with a AT90USB1286 chip that has more I/O pins. The Teensy++ is not a drop-in replacement for the Teensy but similar enough that firmwares often support both with minimal code changes.

Both have Mini-USB sockets. None breaks out the USB port.
They work on 5V from USB, but are able to operate on 3V if a voltage regulator is soldered to the back side. The PD6 pin is also connected to a LED.

{|class="wikitable variants-table sortable"
! Name !! µC !! RAM !! Flash !! EEPROM !! Digital I/O
|-
| Teensy 2.0 || ATmega32u4 || 2.5KB || 2KB || 1KB || 25
|-
| Teensy++ 2.0 || AT90USB1286 || 8K || 128KB || 4K || 45
|}

PJRC expects to discontinue the AVR-based Teensies in 2022, after selling out existing stocks.

===ARM===
The Teensy 3 series (including the Teensy LC) have Freescale microcontrollers with ARM Cortex M-series CPUs.
These have so far not reached as much popularity among enthusasts because there has been a lack of compatible firmware. Some of the µC are supported by [[Kiibohd controller | Kiibohd]].

All have micro-USB port sockets and USB ports' are available as pads on the bottom.
They operate at 3.3V. A few variants are capable of 5V input, but which pins vary between models.

{|class="wikitable variants-table sortable"
! Name !! µC !! MCU !! RAM !! Flash !! EEPROM !! I/O pins+pads
|-
| Teensy 3.2 || MK20DX256 || Cortex M4 72MHz || 64K || 256K || 2K || 24+10 5V-tolerant
|-
| Teensy LC || MKL26Z64 || Cortex-M0+ 48 MHz || 8K || 62K || || 27
|-
| Teensy 3.5 || MK64FX512VMD12 || Cortex-M4F 120 MHz || 256K || 512K || || 40+18 5V-tolerant
|-
| Teensy 3.6 || MK66FX1M0VMD18 || Cortex-M4F 180 MHz || 256K || 1.25M || || 40+18
|-
| Teensy 4.0 || NXP iMXRT1062 || Cortex-M7 600 MHz || 1MB || 2M || || 24+10
|}

The Teensy 3.0, 3.1, 3.2 and LC are mostly pin-compatible with one-another. The LC model is a "low cost" variant.

Teensy 3.5 and 3.6 have a large number of pins, and are also pin-compatible with one-another. The Teensy 3.6 is not 5V-tolerant.

=== Deprecated models===
{| class="wikitable"
! Name
! Microcontroller
! I/O pins
! Flash
|-
| Teensy 1.0
| AT90USB162
| 21
| 15.5 KB
|-
| Teensy 3.0
| MK20DX128 (Cortex M4 48MHz) || 24+10 || 128K
|-
| Teensy 3.1
| MK20DX256 (Cortex M4 72MHz) || 24+10 || 256K
|-
|}