BigTreeTech Adds USB Host Support to ESP 3D Printer Boards

What changed

BigTreeTech pushed a commit to its esp-usb fork on September 7 that adds USB host mass storage class support. The commit lands in the usb_host_msc branch of a repository BigTreeTech forked from Espressif's official esp-usb project.

Why it matters for 3D printing

Most modern 3D printer mainboards use ESP32 or ESP32-S3 chips for WiFi, display, and webcam tasks. Those chips can already act as USB devices, but host mode support is still limited. With mass storage class support in place, an ESP-based board could read a USB flash drive plugged directly into the printer. That means loading G-code without a memory card slot, updating firmware from a stick, or pulling print profiles offline.

Who benefits first

BigTreeTech's SKR, Octopus, and Manta boards are the obvious candidates. Many users already run Klipper on those boards with an ESP32 or S3 for the web interface. USB host support would remove one of the last hardware dependencies in a fully standalone Klipper setup. RepRap firmware users would see the same advantage.

The catch

This is a software push, not a finished feature. The code still needs board-level integration testing, pull request review, and a stable release before most users can enable it. The push is a clear signal that BigTreeTech is investing in the stack, but expect a wait before it appears in default Klipper or BTT firmware builds.

Bottom line

If you run a BigTreeTech board with an ESP chip, USB host support is coming. It will not arrive tomorrow, but the foundation is now in place.