Vehicle interior illumination system

A vehicle interior illumination system comprising:

• a master control unit;
• a plurality of slave control units configured to perform multiplex communication with the master control unit and control a light source mounted on a vehicle in accordance with an instruction of the master control unit;
• a multiplex communication line configured to connect the master control unit to the plurality of slave control units;
• and
• a wireless control unit that is connected to the multiplex communication line and configured to perform wireless communication with an external device,
• wherein the wireless control unit is configured to receive setting information on vehicle interior illumination from the external device and transmit the setting information received from the external device to the master control unit via the multiplex communication line, and
• wherein the master control unit is configured to transmit a control instruction to the slave control unit to control the light source in accordance with the setting information received from the wireless control unit.