Consider the following example of a directional control valve, which has three mechanical positions allowing fluid to flow in different paths.

Figure 5-4 Directional Control Valve

The DRV5055 determines which of the three positions the valve is in. The valve cylinder moves in one dimension (forward and back). By mounting the sensor in the center of the cylinder and placing a magnet on each end of the moving piece, the sensor can detect Strong North, No Field, or Strong South. If V_CC is 3.3 V, corresponding output voltages are roughly 0 V, 1.65 V, or 3.3 V, and a microcontroller ADC can use this to understand the valve position.