How to get USB controller/gamepad to work with python

Question

I have a USB controller that I'm trying to get inputs from, a Microsoft® SideWinder® Plug & Play Game Pad. I'm having difficulties trying to figure out how to receive its inputs correctly. Unfortunately, I cannot use pygame as it requires a window to receive inputs from, but I have to generate a pyglet window (via PsychoPy) to run my program. With pygame it can connect and show the state of buttons, but it cannot receive inputs without creating a window. I tried looking for other libraries, but all I encountered was Inputs, which isn't compatible with my controller (doesn't detect the device after installing). The controller itself works as I've tested it with an online gamepad tester. PsychoPy's joystick API is currently broken and does not work, so no luck there either.

I was really hoping anyone had advice on how to receive inputs from my controller/gamepad into my program?

Are you stuck to using PyGlet? I found this: https://entitycrisis.blogspot.com/2008/02/pyglet-joystick.html — Kingsley, Feb 19 '20 at 21:53
I am, unfortunately I am using a windows machine and that seems to only be functional for linux, thank you though! — , Feb 20 '20 at 00:14
*"it cannot receive inputs without creating a window"* - of course. In windows you will need the message loop of the window, to receive the inputs. — Rabbid76, Feb 20 '20 at 09:49

score 6 · Accepted Answer · edited Aug 14 '21 at 04:01

For Windows you can use the WINMM.dll directly.

Use the ctypes library to load the dll (see Loading shared libraries). Use ctypes.WINFUNCTYPE to create prototypes for the function:

import ctypes

winmmdll = ctypes.WinDLL('winmm.dll')

# [joyGetNumDevs](https://learn.microsoft.com/en-us/windows/win32/api/joystickapi/nf-joystickapi-joygetnumdevs)
"""
UINT joyGetNumDevs();
"""
joyGetNumDevs_proto = ctypes.WINFUNCTYPE(ctypes.c_uint)
joyGetNumDevs_func  = joyGetNumDevs_proto(("joyGetNumDevs", winmmdll))

# [joyGetDevCaps](https://learn.microsoft.com/en-us/windows/win32/api/joystickapi/nf-joystickapi-joygetdevcaps)
"""
MMRESULT joyGetDevCaps(UINT uJoyID, LPJOYCAPS pjc, UINT cbjc);

32 bit: joyGetDevCapsA
64 bit: joyGetDevCapsW

sizeof(JOYCAPS): 728
"""
joyGetDevCaps_proto = ctypes.WINFUNCTYPE(ctypes.c_uint, ctypes.c_uint, ctypes.c_void_p, ctypes.c_uint)
joyGetDevCaps_param = (1, "uJoyID", 0), (1, "pjc", None), (1, "cbjc", 0)
joyGetDevCaps_func  = joyGetDevCaps_proto(("joyGetDevCapsW", winmmdll), joyGetDevCaps_param)

# [joyGetPosEx](https://learn.microsoft.com/en-us/windows/win32/api/joystickapi/nf-joystickapi-joygetposex)
"""
MMRESULT joyGetPosEx(UINT uJoyID, LPJOYINFOEX pji);
sizeof(JOYINFOEX): 52
"""
joyGetPosEx_proto = ctypes.WINFUNCTYPE(ctypes.c_uint, ctypes.c_uint, ctypes.c_void_p)
joyGetPosEx_param = (1, "uJoyID", 0), (1, "pji", None)
joyGetPosEx_func  = joyGetPosEx_proto(("joyGetPosEx", winmmdll), joyGetPosEx_param)

Create the python function joyGetNumDevs, joyGetDevCaps and joyGetPosEx which delegate to the DLL. And create classes for the types JOYCAPS respectively JOYINFOEX:

# joystickapi - joyGetNumDevs
def joyGetNumDevs():
    try:
        num = joyGetNumDevs_func()
    except:
        num = 0
    return num

# joystickapi - joyGetDevCaps
def joyGetDevCaps(uJoyID):
    try:
        buffer = (ctypes.c_ubyte * JOYCAPS.SIZE_W)()
        p1 = ctypes.c_uint(uJoyID)
        p2 = ctypes.cast(buffer, ctypes.c_void_p)
        p3 = ctypes.c_uint(JOYCAPS.SIZE_W)
        ret_val = joyGetDevCaps_func(p1, p2, p3)
        ret = (False, None) if ret_val != JOYERR_NOERROR else (True, JOYCAPS(buffer))   
    except:
        ret = False, None
    return ret 

# joystickapi - joyGetPosEx
def joyGetPosEx(uJoyID):
    try:
        buffer = (ctypes.c_uint32 * (JOYINFOEX.SIZE // 4))()
        buffer[0] = JOYINFOEX.SIZE
        buffer[1] = JOY_RETURNALL
        p1 = ctypes.c_uint(uJoyID)
        p2 = ctypes.cast(buffer, ctypes.c_void_p)
        ret_val = joyGetPosEx_func(p1, p2)
        ret = (False, None) if ret_val != JOYERR_NOERROR else (True, JOYINFOEX(buffer))   
    except:
        ret = False, None
    return ret 

JOYERR_NOERROR = 0
JOY_RETURNX = 0x00000001
JOY_RETURNY = 0x00000002
JOY_RETURNZ = 0x00000004
JOY_RETURNR = 0x00000008
JOY_RETURNU = 0x00000010
JOY_RETURNV = 0x00000020
JOY_RETURNPOV = 0x00000040
JOY_RETURNBUTTONS = 0x00000080
JOY_RETURNRAWDATA = 0x00000100
JOY_RETURNPOVCTS = 0x00000200
JOY_RETURNCENTERED = 0x00000400
JOY_USEDEADZONE = 0x00000800
JOY_RETURNALL = (JOY_RETURNX | JOY_RETURNY | JOY_RETURNZ | \
                 JOY_RETURNR | JOY_RETURNU | JOY_RETURNV | \
                 JOY_RETURNPOV | JOY_RETURNBUTTONS)

# joystickapi - JOYCAPS
class JOYCAPS:
    SIZE_W = 728
    OFFSET_V = 4 + 32*2
    def __init__(self, buffer):
        ushort_array = (ctypes.c_uint16 * 2).from_buffer(buffer)
        self.wMid, self.wPid = ushort_array  

        wchar_array = (ctypes.c_wchar * 32).from_buffer(buffer, 4)
        self.szPname = ctypes.cast(wchar_array, ctypes.c_wchar_p).value
        
        uint_array = (ctypes.c_uint32 * 19).from_buffer(buffer, JOYCAPS.OFFSET_V) 
        self.wXmin, self.wXmax, self.wYmin, self.wYmax, self.wZmin, self.wZmax, \
        self.wNumButtons, self.wPeriodMin, self.wPeriodMax, \
        self.wRmin, self.wRmax, self.wUmin, self.wUmax, self.wVmin, self.wVmax, \
        self.wCaps, self.wMaxAxes, self.wNumAxes, self.wMaxButtons = uint_array

# joystickapi - JOYINFOEX
class JOYINFOEX:
  SIZE = 52
  def __init__(self, buffer):
      uint_array = (ctypes.c_uint32 * (JOYINFOEX.SIZE // 4)).from_buffer(buffer) 
      self.dwSize, self.dwFlags, \
      self.dwXpos, self.dwYpos, self.dwZpos, self.dwRpos, self.dwUpos, self.dwVpos, \
      self.dwButtons, self.dwButtonNumber, self.dwPOV, self.dwReserved1, self.dwReserved2 = uint_array

See the simple example to test the API:

import joystickapi
import msvcrt
import time

print("start")

num = joystickapi.joyGetNumDevs()
ret, caps, startinfo = False, None, None
for id in range(num):
    ret, caps = joystickapi.joyGetDevCaps(id)
    if ret:
        print("gamepad detected: " + caps.szPname)
        ret, startinfo = joystickapi.joyGetPosEx(id)
        break
else:
    print("no gamepad detected")

run = ret
while run:
    time.sleep(0.1)
    if msvcrt.kbhit() and msvcrt.getch() == chr(27).encode(): # detect ESC
        run = False

    ret, info = joystickapi.joyGetPosEx(id)
    if ret:
        btns = [(1 << i) & info.dwButtons != 0 for i in range(caps.wNumButtons)]
        axisXYZ = [info.dwXpos-startinfo.dwXpos, info.dwYpos-startinfo.dwYpos, info.dwZpos-startinfo.dwZpos]
        axisRUV = [info.dwRpos-startinfo.dwRpos, info.dwUpos-startinfo.dwUpos, info.dwVpos-startinfo.dwVpos]
        if info.dwButtons:
            print("buttons: ", btns)
        if any([abs(v) > 10 for v in axisXYZ]):
            print("axis:", axisXYZ)
        if any([abs(v) > 10 for v in axisRUV]):
            print("roation axis:", axisRUV)

print("end")

The api binding and example is provided in the GitHub repository python_windows_joystickapi

Remark: `ctypes` module usually already have signatures, so you can call `ctypes.windll.winmm.joyGetDevCapsW` etc. like a normal function, without having to declare the function signature. Read the module documentation for more details. Also, error codes can be found at https://autohotkey.com/board/topic/17212-midi-output-from-ahk/ or https://www.hbtapi.com/help/Units/mmsystem.pas/Constants/MMSYSERR_%20Constants.htm — user202729, Aug 18 '21 at 07:21

How to get USB controller/gamepad to work with python

1 Answers1