OCC is a pragmatic version of VLC based on a smart device camera that allows easier implementation of various services in smart devices. This article presents a flexible and novel motion detection scheme over a smart device camera in OCC. The motion detection is conducted in conjunction with a static downlink optical camera communication, where a mobile phone front camera is employed as the receiver and an 8 x 8 dot matrix LED as the transmitter. In addition to the 8 x 8 dot matrix LED for data transmission, 10 white LEDs are also employed for providing illumination, acquiring camera focus, and light metering. The motion detection or MoC is designed to detect the user's finger movement through the OCC link via the camera. A simple but efficient quadrant division based motion detection algorithm is proposed for reliable and accurate detection of motion. The experiment and simulation results demonstrate that the proposed scheme is able to detect motion with a success probability of up to 96 percent in the mobile phone camera based OCC. It is envisioned that the proposed motion detection can facilitate cost-effective and convenient smart home environments in the OCC, where the provision of illumination and short-range wireless communications has already been addressed.