The HW-044 is a self-contained, dual-axis analog joystick module. It is often incorrectly referred to as a "PS2 joystick module" because its physical form factor and electrical behavior mimic the thumbsticks found on PlayStation 2 controllers. The module outputs two independent analog voltages (X and Y axes) proportional to the stick’s position, along with a digital output for a built-in push-button switch that activates when the stick is pressed down vertically (the "SEL" or "KEY" signal).
Uses the robust MAX3232 chip, guaranteeing valid RS232 voltage levels. hw-044 datasheet