Joystick: learn axis min/max (commaai#23377)

* Joystick: learn axis min/max

* clean up updating max/min

Co-authored-by: Willem Melching <willem.melching@gmail.com>

tools/joystick/joystickd.py

@@ -34,7 +34,8 @@ def update(self):
 
 class Joystick:
   def __init__(self):
-    self.max_axis_value = 255  # tune based on your joystick, 0 to this
+    self.min_axis_value = 0
+    self.max_axis_value = 255
     self.cancel_button = 'BTN_TRIGGER'
     self.axes_values = {'ABS_Y': 0., 'ABS_RZ': 0.}  # gb, steer
 
@@ -45,7 +46,10 @@ def update(self):
     if event[0] == self.cancel_button and event[1] == 0:  # state 0 is falling edge
       self.cancel = True
     elif event[0] in self.axes_values:
-      norm = -interp(event[1], [0, self.max_axis_value], [-1., 1.])
+      self.max_axis_value = max(event[1], self.max_axis_value)
+      self.min_axis_value = min(event[1], self.min_axis_value)
+
+      norm = -interp(event[1], [self.min_axis_value, self.max_axis_value], [-1., 1.])
       self.axes_values[event[0]] = norm if abs(norm) > 0.05 else 0.  # center can be noisy, deadzone of 5%
     else:
       return False