The BIQU BX is advertised as "RPi integrated". This statement can understandably cause a lot of confusion as to what it actually means. Some people have an expectation that it means that the pi will not need to connect to the front USB port of the machine. Others may have a different expectation.
The reality is that the integration comes in the form of a very clean mounting solution for the Pi combined with the ability to power and interface with the pi using the machine (touch interface). The USB port on the back of the TFT that connects to the pi does not offer a serial link back to the motherboard. It simply interfaces with a little MCU (CH554G) that translates the I2C signals from the touch controller on the TFT into signals that the pi can understand over USB. If you want the raspberry pi to communicate with the motherboard in order to send and receive commands (hint: you do) then you are still going to need a USB cable running from the pi to the micro USB po