A point-of-sale (POS) device includes a processor, a universal serial bus (USB) hub, two switches, and an external connector that connects the POS device to a secondary device with its own second processor. In a primary mode, the processor is connected to a host connector of the USB hub and the secondary device is connected to a first peripheral connector of the USB hub via the external connector. In a secondary mode, the processor is connected to the first peripheral connector of the USB hub and the secondary device is connected to the host connector of the USB hub via the external connector. The processor controls the switch from the primary mode to the secondary mode, and vice versa, by transmitting control signals to control pins of the two switches, and optionally by transmitting a reset signal to a reset pin of the USB hub.