Abstract: A toilet training device comprises a processor, a housing, several light-based time of flight (TOF) sensors, several LEDs, a sensor enclosure, and a clip. The clip attaches the device to the rim of a toilet bowl pointing the TOF sensors towards the water surface inside the toilet bowl. Each TOF sensor projects several light beams towards the toilet bowl, receives light reflected, makes measurements of the distance to the nearby object, and makes measurements of the signal strength of the reflected light. The processor generates a contour map and identifies one or more zones of interest as the water surface based on the distant measurements, determines excrement is released in the toilet bowl changes in the signal strength measurements are outside a signal strength range, and displays LED light patterns in response to determining the excrement is released in the toilet bowl.