This is a small PCB (Printed Circuit Board) consisting of a port expander with an I2C interface and four analog switch chips, each with 4 switches. The purpose of this PCB is to interface with a mini PC (such as a Raspberry Pi) using a small utility program to control the switches. The intention is to use the PCB in the testing of a keypad, specifically to close the rows and columns of a keypad matrix, simulate key presses, and enable automated testing. This setup allows for efficient and precise testing procedures to be conducted on the keypad. The port expander facilitates communication between the mini PC and the switches via the I2C protocol, enabling the mini PC to send commands to the PCB to control the state of the switches. The analog switch chips provide the capability to open and close connections between different points on the PCB, mimicking the behavior of physical key presses on the keypad. Overall, this PCB setup streamlines the testing process for keypad functionality, offering a reliable and adaptable solution for conducting automated tests on keypad matrices.