The code that finally worked doesn't rely on a "library" in the traditional Arduino sense (like something you download from a Library Manager). Instead, it uses the Native ESP-IDF USB Host Stack (Esp32S3).
Most Arduino USB libraries are written for external chips (like the MAX3421E). This code, at change, talks directly to the internal USB engine of the ESP32-S3.
The point is the use of "usb_host_interface_claim". USB devices are protective; they won't accept data until a Host explicitly "claims" the interface.
By manually scanning the descriptors, we stopped "guessing" if the printer was on address 1 or 2 and let the esp32s3 find the correct path.
-.usb_host_install Powers on the USB hardware inside the ESP32-S3.
-.usb_host_client_register Creates a "listener" for when you plug/unplug the cable.
-.usb_host_interface_claim Locks the printer so it only listens to your ESP32.
-.usb_host_transfer_submit Pushes the ESC/POS bytes through the wire to the thermal head.
https://www.youtube.com/shorts/tLLG3RAhL6I
I also tested the printing on an Epson TM-T20II USB printer. It printed very well as well.
For years I have developed printing systems over the Internet, but this many times required the use of microcontrollers that printed over serial/RS232 ports. Now, I will be able to use USB printers, which are more modern and accessible.
