Teensy 4.1 features the fastest microcontroller and an expanded set of powerful peripherals in a 2.4 by 0.7 inch form factor.

Teensy 4.0 can be programmed using the Arduino IDE with Teensyduino add-on.

Technical Specifications Compared to Teensy 4.0

Teensy 4.1 & 4.0 use the same IMXRT1062, so most technical specifications are the same.

Please refer to the Teensy 4.0 page for common specifications and features.

Feature	Teensy 4.1	Teensy 4.0
Ethernet	10 / 100 Mbit DP83825 PHY (6 pins)	-none-
USB Host	5 Pins with power management	2 SMT Pads
SDIO (4 bit data)	Micro SD Socket	8 SMT Pads
PWM Pins	35	31
Analog Inputs	18	14
Serial Ports	8	7
Flash Memory	8 Mbyte	2 Mbyte
QSPI Memory	2 chips Plus Program Memory	Program memory only
Breadboard Friendly I/O	42	24
Bottom SMT Pad Signals	7	16
SD Card Signals	6	0
Total I/O Pins	55	40

Pinouts

Teensy 4.1 is designed to bring all general purpose I/O pins to breadboard friendly pads on the outside edges

Ethernet

To use the Ethernet port, a magjack and capacitor need to be connected.

This is currently available only as a DIY project using this OSH Park Shared Circuit Board.

Memory Expansion

The bottom side of Teensy 4.1 has locations to solder 2 memory chips. 

The smaller location is meant for a PSRAM chip. The larger location is intended for flash memory.

USB Host

Teensy 4.1's USB Host port allow you to connect USB devices, like keyboards and MIDI musical instruments. A 5 pin header and a USB Host cable are needed to be able to plug in a USB device.

USB hubs may be used if more than 1 device is needed. See the USBHost_t36 examples for details.