Hi, let's bring this project to reality.
Let me know the type/series of hall effect sensor you use.
as I know that hall effect sensor has 1 or 0 data , right, so we will use digital input pin, and it would be combination of them that would be threat as joystick, so, it maybe use 4 hall to detect 4 direction, or more. that what I get from your description.
let's discuss this project further more over chat.
best Regards,
Rijal