NOTE: Due to shortages and price increases on the Ethernet PHY chip, the Teensy 4.1 microcontroller is now being offered both with and without the Ethernet feature. The type can be chosen at checkout.
Teensy 4.1 is the latest Teensy microcontroller development board from PJRC. It features an ARM Cortex-M7 IMXRT1062 processor at 600 MHz. The actual size is 2.4 by 0.7 inch, the same form-factor as Teensy 3.6.
Teensy 4.1 uses the same processor as Teensy 4.0, but provides greater I/O capability, including an optional ethernet PHY, SD card socket, and USB host port. Teensy 4.1 also comes with 4X larger flash memory, and has 2 locations to optionally add more memory.
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 | Optional 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.

Note: The Teensy 4.1 does not include headers and, if needed in your application, will need to be purchased separately and soldered on yourself.
Resources: