The PS2-style joystick module contains two 10 kΩ potentiometers arranged on perpendicular axes and a tactile push switch actuated by pressing the shaft. Each axis outputs an analog voltage proportional to deflection.
| Supply voltage | 3.3 – 5 V |
| X / Y output | 0 – VCC (analog) |
| Center voltage | ~VCC/2 (±50 mV tolerance) |
| Switch | Momentary NO active-LOW |
| Potentiometer | 10 kΩ dual-gang |
| Travel | ±30° per axis |
Each axis is a voltage divider — the wiper position follows the shaft deflection, outputting 0 V at one extreme and VCC at the other, with VCC/2 at center. An ADC reads both channels; the push switch requires a pull-up resistor on the SW pin.
Center position drifts 5–50 mV from ideal VCC/2 — calibrate per-unit. Potentiometers wear over time. Not self-centering beyond spring return. Cheap modules have high center jitter — apply ±5% dead zone in software.