Embedded Lab

Rex Chen and Ziqi Yang have built a hand gesture lock system that utilizes a series of hand signs as a password to authenticate. The pattern of hand signs are imaged through a CMOS image sensor, and are analyzed using a PIC32 microcontroller to determine whether the observed sequence of the gestures match with the one that is pre-recorded into the system.

The Hand Sign Lock demonstrates the high-level design of the project and can be divided into four main parts: CMOS camera, control, PIC32 microcontroller, and thin film transistor (TFT) screen. The OV7670 CMOS camera provides images for the PIC32 microcontroller, and the buttons in the control module allows the user to select the appropriate mode and to perform actions when calibrating or resetting the password. The PIC32 microcontroller utilizes Otsu’s method for thresholding to transform the grayscale image to a binary (black and white) image. In addition, the microcontroller has multiple modes for a more intuitive user interface and constantly updates the TFT screen with the appropriate messages. Depending on the mode, after a image is received from the CMOS camera, the image is printed to the TFT screen for the user to view as well as for debugging purposes, which is helpful for determining functionality of the calibration step and evaluating the results from the thresholding algorithm.

See the demo video of this project below: