How to Add 5-Pin DIN MIDI Out to M8 Headless Music Tracker

The Teensy 4.1 MIDI out circuit is based on the MIDI out portion of this diagram. 

Teensy ground goes to MIDI connector pin 2. 

Teensy digital pin 1 (serial TX) goes to MIDI connector pin 5 via a 47 ohm resistor. 

Teensy 3.3V goes to MIDI connector pin 4 via 47 ohm resistor. 

Here are the pinouts of the Teensy 4.1 with the relevant pins highlighted: