Setting the IO Voltage

Serial Port 1 and the I2C interface requires the Voltage Select Jumper be installed.

• Install the Voltage Select Jumper. Place it on the 5V pins if you are connecting to a 5V I/O controller (like an Arduino Mega/Uno/Nano). Place it on the 3.3V side if connecting to an ESP32 or another Teensy directly.

Jumper installed for 5V operation