Teensy 4.1


Platform Teensy: Teensy is a complete USB-based microcontroller development system, in a very small footprint, capable of implementing many types of projects. All programming is done via the USB port. No special programmer is needed, only a standard USB cable and a PC or Macintosh with a USB port.

Microcontroller IMXRT1062
Frequency 600MHz
Flash 7.75MB
Vendor Teensy


Please use teensy41 ID for board option in “platformio.ini” (Project Configuration File):

platform = teensy
board = teensy41

You can override default Teensy 4.1 settings per build environment using board_*** option, where *** is a JSON object path from board manifest teensy41.json. For example, board_build.mcu, board_build.f_cpu, etc.

platform = teensy
board = teensy41

; change microcontroller
board_build.mcu = imxrt1062

; change MCU frequency
board_build.f_cpu = 600000000L


Teensy 4.1 supports the next uploading protocols:

  • jlink
  • teensy-cli
  • teensy-gui

Default protocol is teensy-gui

You can change upload protocol using upload_protocol option:

platform = teensy
board = teensy41

upload_protocol = teensy-gui


Debugging - “1-click” solution for debugging with a zero configuration.


You will need to install debug tool drivers depending on your system. Please click on compatible debug tool below for the further instructions and configuration information.

You can switch between debugging Tools & Debug Probes using debug_tool option in “platformio.ini” (Project Configuration File).

Teensy 4.1 does not have on-board debug probe and IS NOT READY for debugging. You will need to use/buy one of external probe listed below.

Compatible Tools On-board Default
J-LINK   Yes


Name Description
Arduino Arduino Wiring-based Framework allows writing cross-platform software to control devices attached to a wide range of Arduino boards to create all kinds of creative coding, interactive objects, spaces or physical experiences