The teensy receives serial data via USB and uses the octows2811 adapter to send rgb data to the LEDs.
Serial data can be sent from either a mac running sousaVFX, or a raspberry pi running sousaFX-rnbo.
The teensy auto-detects whether it's connected to a mac or rpi by measuring the frame size of the incoming serial data.
Each frame's start marker is 254, and end marker is 255. SousaVFX sends hundreds of rgb values in each frame. sousaFX-rnbo sends three parameter values in each frame, and relies on the teensy to generate visuals.
https://edu.sousastep.quest/content/tutorials/LED-sousa-bell.html#materials