I would not be surprised if those 7 wires are 3 power (blk gry wht) and 4 USB. Maybe it’s actually 2 serial data lines, control and text? Maybe try to trace out the PCB and get any identifying marks from the ICs? If one is a microcontroller or ram or rom or a USB controller that would go a long way in getting it reverse engineered. For real though, they probably are using standards like i2c or USB or rs232, no sense reinventing what works