Teensy 4.1

The Teensy 4.1 is the latest Teensy, offering the fastest micocontroller and an expanded set of powerful peripherals in a 2.4 by 0.7 inch form factor. In common with the Teensy 4.0, it can be programmed using the Arduino IDE with Teensyduino add-on. Teensy 4.1 is designed to bring all general purpose I/O pins to breadboard friendly pads on the outside edges.

While it shares many similarities with the Teensy 4.0 there are some important differences.

**Teensy 4 series comparison**
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

All Teensy boards are shipped assembled (without headers) and fully tested.

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.

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. PJRC is planning to offer this as a DIY kit in the near future. You can also make the connection by soldering wires.

These parts are recommended to build the Ethernet connection.

1	Ethernet Magjack	Hobbytronics RJ45 Ethernet MagJack
2	Header, 3x2, 2mm pitch	Digikey 1849-1000-ND
2	IDC Socket, 3x2, 2mm pitch	Amphenol FCI 89361-706LF, Digikey 609-3139-ND
1	Ribbon Cable, 3 to 6 inch	Digikey HF06S-5-ND
1	Capacitor, 0.1uF, 805
1	Capacitor, 1uF, 805	probably not needed
1	Capacitor, 1nF, 805	optional, should be high voltage rated if used
1	Resistor, 1M	optional
1	Circuit Board	OSH Park Shared PCB

Memory Expansion

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

Teensy 4.1

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

Teensy 4.1

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.