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The Teensy 4.0 pairs an NXP i.MX RT1062 processor with a 600 MHz Arm Cortex-M7 and can be programmed in the Arduino IDE using PJRC’s Teensy boards add-on. It is a compact, capable development board—not a drop-in promise that every Arduino sketch or shield will work unchanged. Its 3.3 V-only pins, available interfaces, and lack of onboard Ethernet and microSD are important project constraints.
What the Teensy 4.0 brings to Arduino-style development
PJRC specifies the Teensy 4.0 around the NXP i.MX RT1062, with an Arm Cortex-M7 rated at 600 MHz. That gives developers a much faster-clocked 32-bit microcontroller platform than many familiar entry-level Arduino boards, while retaining an Arduino IDE workflow through PJRC’s board support package. The clock rating alone does not establish how quickly a particular project will run: actual performance depends on the code, peripherals, libraries, and workload.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
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Teensy 4.0 (Headers) | $26.80 | Buy on Amazon |
| 2 |
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Teensy 4.0 (Without Pins) | $23.80 | Buy on Amazon |
| 3 |
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Teensy 4.0 iMXRT1062 Microcontroller Development Board (Lockable Version) | $23.80 | Buy on Amazon |
| 4 |
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Teensy 4.0 iMXRT1062 Microcontroller Development Board (Standard Non-Lockable Version) | $23.80 | Buy on Amazon |
| 5 |
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Teensy 4.1 (with Pins) | $43.08 | Buy on Amazon |
In PJRC’s wording, the board has 40 total input/output signal pins. Its published specifications include 1024 KB RAM, of which 512 KB is described as tightly coupled, 1984 KB flash, and 1 KB emulated EEPROM. The separate pins-soldered product page describes 2048K flash with 64K reserved for recovery and EEPROM emulation; treat the detailed specification and product-page figure as differently stated capacity figures, not as a guarantee that all nominal flash is available to an application. PJRC Teensy 4.0 specifications and PJRC pins-soldered product page provide the manufacturer’s descriptions.
Which interfaces are available?
The Teensy 4.0 is useful when a project needs several communications buses or audio connections in a small board. PJRC lists these interfaces and I/O counts:
#1 Best Overall
- Features am ARM Cortex-M7 processor at 600MHz with a NXP iMXRT1062 chip: a true real-time microcontroller platform
- Dual-issue superscaler processor: Can execute two instructions per clock cycle
- Tightly Coupled Memory: allows fast single cycle access to memory using a pair of 64 bit wide buses
- Provides a power shut-off feature: By connecting a pushbutton to the On/Off pin, the 3.3V power supply can be completely disabled by holding the button for 5 seconds, & turned back on by a brief button press
- The same size and shape as Teensy 3.2: Retains compatibility with most of the pin functions. Pre soldered header pins
| Capability | Teensy 4.0 specification |
|---|---|
| Digital I/O | 40 signal pins |
| PWM outputs | 31 |
| Analog inputs | 14 |
| Serial | 7 ports |
| SPI | 3 |
| I²C | 3 |
| CAN | 3, including 1 CAN FD |
| Audio | 2 I²S/TDM and 1 S/PDIF |
| DMA | 32 general-purpose channels |
These are board specifications, not a claim that every interface can be used simultaneously on any arbitrary pin combination. Consult PJRC’s Teensy 4.0 pinout and product details when planning pin assignments. PJRC says 24 pins are readily accessible on a solderless breadboard. The board shares the size and shape of Teensy 3.2 and retains compatibility with most of that model’s pin functions; this does not mean all hardware or software behavior is identical.
Check the 3.3 V electrical limit before wiring
Teensy 4.0 digital inputs accept 0–3.3 V and are explicitly not 5 V tolerant, according to PJRC. Do not connect a 5 V logic output directly to a digital pin. If another device uses 5 V signaling, design an appropriate level-shifting or interface circuit and confirm that its signal levels suit both sides. This electrical difference can determine whether the board connects directly to an existing sensor, controller, or Arduino-oriented module.
Rank #2
- 1024K RAM (512K of Tightly Coupled Memory)
- 2048K Flash (64K Reserved for Recovery & EEPROM Emulation)
- 2 USB Ports (Both 480 MBit/Sec)
- 3 CAN Bus (1 with CAN FD), 2 I2S Digital Audio
PJRC gives approximate current consumption of 100 mA at 600 MHz. This is a manufacturer’s approximate board figure, not a measurement of a complete project with attached sensors, displays, radios, or USB devices. Consumption varies with clock speed and project load; PJRC says lowering the CPU speed to 528 MHz or below reduces consumption. Estimate battery life using the actual assembled system and workload rather than treating 100 mA as a universal draw.
The Tool Desk
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The board supports USB device and host capability, but host connectivity is brought out through two SMT pads rather than a standard host connector. PJRC cautions that the board does not include circuitry to manage power to USB devices. Do not hot-plug USB devices when the Teensy is powered from USB or from a limited 5 V supply; plan the host-side connector and power arrangement for the peripheral.
Rank #3
- HIGH-PERFORMANCE MICROCONTROLLER: Features an ARM Cortex-M7 processor at 600MHz (can be overclocked), with a NXP iMXRT1062 chip, the most powerful microcontroller available today
- ARDUINO-COMPATIBLE: The Teensy is compatible with the Arduino IDE programming environment as well as many of the existing Arduino libraries, so it is easy to get programmed and running
- RAM: 1024K RAM (512K is tightly coupled); 2048K Flash (64K reserved for recovery & EEPROM emulation)
- MULTIPLE I/O: 2 USB ports, both 480 MBit/sec; 3 CAN Bus (1 with CAN FD); 31 PWM pins; 40 digital pins, all interrupt capable; 14 analog pins, 2 ADCs on chip; 2 I2S Digital Audio
- LOCKABLE PROGRAM CODE OPTION: The LOCKABLE version of the Teensy 4.0 is suitable for commercial products and secure applications to protect your program code from unauthorized access and copying. When code security is not required, we recommend the STANDARD NON-LOCKABLE version.
Set up the Arduino IDE and choose libraries deliberately
PJRC identifies Arduino IDE plus the Teensy boards add-on as the primary programming environment. The add-on is installed through Boards Manager and includes libraries tested and optimized for Teensy. That is the practical meaning of Arduino compatibility: an Arduino-style workflow and a maintained board package, not automatic compatibility with every library, shield, or sketch written for a different Arduino target.
- Install the Arduino IDE.
- In Arduino IDE, open Boards Manager, find the Teensy board support package, and install it.
- Select the Teensy 4.0 board target before compiling and uploading a sketch.
- For each library or attached module, check that it supports the Teensy 4.0 processor, required interface, and 3.3 V signaling.
PJRC also lists PlatformIO, Visual Micro for Windows, command-line Makefiles, and CircuitPython as options. PJRC notes that CircuitPython does not fully support all Teensy 4.0 hardware, so verify that the specific peripheral and feature your project requires are supported in the chosen environment. The manufacturer’s Teensy 4.0 product page lists the board’s software options.
Rank #4
- HIGH-PERFORMANCE MICROCONTROLLER: Features an ARM Cortex-M7 processor at 600MHz (can be overclocked), with a NXP iMXRT1062 chip, the most powerful microcontroller available today
- ARDUINO-COMPATIBLE: The Teensy is compatible with the Arduino IDE programming environment as well as many of the existing Arduino libraries, so it is easy to get programmed and running
- RAM: 1024K RAM (512K is tightly coupled); 2048K Flash (64K reserved for recovery & EEPROM emulation)
- MULTIPLE I/O: 2 USB ports, both 480 MBit/sec; 3 CAN Bus (1 with CAN FD); 31 PWM pins; 40 digital pins, all interrupt capable; 14 analog pins, 2 ADCs on chip; 2 I2S Digital Audio
- LOCKABLE PROGRAM CODE OPTION: The LOCKABLE version of the Teensy 4.0 is suitable for commercial products and secure applications to protect your program code from unauthorized access and copying. When code security is not required, we recommend the STANDARD NON-LOCKABLE version.
Teensy 4.0 or Teensy 4.1?
Both boards are in the Teensy 4 family, but the expansion features differ in ways that may matter more than a headline processor speed. PJRC’s comparison identifies the following distinctions relevant to a project choice:
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| Project consideration | Teensy 4.0 | Teensy 4.1 |
|---|---|---|
| Ethernet | No onboard Ethernet | Onboard Ethernet |
| Removable storage | SDIO pads only | microSD socket |
| Accessible I/O | 24 pins readily accessible on a solderless breadboard | Additional accessible I/O; exact count not stated on the cited PJRC page |
Choose the 4.0 when its smaller footprint and the interfaces it exposes suit the design, especially if Ethernet and a built-in microSD socket are unnecessary. Consider the 4.1 when onboard networking, convenient microSD access, or additional accessible I/O is central. Check PJRC’s Teensy 4.0 documentation for the 4.0’s SDIO-pad detail and the linked Teensy 4.1 product information for its socket and expansion options.
Best Value
- Pre-Soldered Header Pins
- ARM Cortex-M7 at 600 MHz
- 4X Larger Flash Memory
- Provides Greater I/O Capability
- Includes Ethernet PHY, SD Card Socket, and USB Host Port
Account for board revision when a fix matters
PJRC says Teensy 4.0 boards made after December 2021 use the MIMXRT1062DVL6B processor revision; earlier boards used a version ending in A. PJRC says the B revision fixes CAN bus and USB device isochronous-mode bugs. If a project depends on either behavior, identify the actual board revision rather than assuming it from the Teensy 4.0 name. PJRC also records component changes after March 2022, June 2022, and August 2022 on its product documentation.
When the Teensy 4.0 is a good fit
- Use it when a compact board needs substantial microcontroller processing capability and its particular buses, PWM, analog inputs, or audio interfaces match the design.
- Check signal voltage first if connecting existing 5 V equipment; direct 5 V digital signals are not supported.
- Plan separately for Ethernet or microSD if the project requires either, since the 4.0 has neither onboard Ethernet nor a microSD socket.
- Choose software and libraries based on documented support for the target board and peripheral, rather than assuming all Arduino ecosystem code transfers unchanged.
- Measure or estimate power for the complete application under its real clock and peripheral load, especially for battery-powered builds.
PJRC lists a USB cable and two 14×1 pin strips as recommended accessories. Connector, header, and USB host-cable needs depend on the board revision and how it will be assembled, so verify the hardware configuration before ordering a specific accessory. PJRC’s pins-soldered product page distinguishes the board configuration and recommended items.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
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