Moving Deadzone Filter Plugin for Joystick Gremlin

deadzone_filter.py

import gremlin
from gremlin.user_plugin import *


mode = ModeVariable("Mode", "The mode in which to use this mapping")

virtual_axis = VirtualInputVariable(
        "Virtual output axis",
        "The vJoy axis to send the filtered output to.",
        [gremlin.common.InputType.JoystickAxis]
)

physical_axis = PhysicalInputVariable(
        "Physical input axis",
        "The physical input axis being filtered.",
        [gremlin.common.InputType.JoystickAxis]
)

deadzone = IntegerVariable(
        "Deadzone size",
        "Size of the deadzone around the cached value.",
        5,
        0,
        100
)

# Decorator for the physical axis 
dec_physical_axis = physical_axis.create_decorator(mode.value)

# Global variables
# The cached physical input
g_cached_value = 0.0
# The current input
g_current_value = 0.0
g_vjoy = gremlin.joystick_handling.VJoyProxy()

def apply_deadzone():
    global g_current_value, g_cached_value
    if(abs(g_current_value - g_cached_value) > deadzone.value/100):
        g_cached_value = g_current_value
    return g_cached_value

def update_vjoy():
    global g_vjoy
    g_vjoy[virtual_axis.vjoy_id].axis(virtual_axis.input_id).value = apply_deadzone()

@dec_physical_axis.axis(physical_axis.input_id)
def axis_cb(event):
    global g_current_value
    g_current_value = event.value
    update_vjoy()

For users experiencing ghosting/fluctuating/spinking/noisy axis inputs (as for example prevalent with the rotaries on the Saitek/Logitech X55/X56), this Joystick Gremlin user plugin implements a moving deadzone around the last input value of the filtered axis.

To use, add this plugin to Joystick Gremlin and create an instance of this plugin for any troubling input axis. Pay attention to NOT also remap the to be filteres axes to a virtual one, else the plugin will not work. To confirm the plugin working, set a high deadzone, enable Gremlin and observe the difference in axis inputs between the physical and virtual devices you configured.

For general Joystick Gremlin related questions and issues, please refer to the above linked repository.