adding circuitpython example for USB Host with SNES like gamepad

Author: FoamyGuy

USB_SNES_Gamepad/CircuitPython_USB_Host/code.py

@@ -0,0 +1,193 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 Tim Cocks for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+import array
+import time
+import usb.core
+import adafruit_usb_host_descriptors
+
+# Set to true to print detailed information about all devices found
+VERBOSE_SCAN = True
+
+BTN_DPAD_UPDOWN_INDEX = 1
+BTN_DPAD_RIGHTLEFT_INDEX = 0
+BTN_ABXY_INDEX = 5
+BTN_OTHER_INDEX = 6
+
+DIR_IN = 0x80
+controller = None
+
+if VERBOSE_SCAN:
+    for device in usb.core.find(find_all=True):
+        controller = device
+        print("pid", hex(device.idProduct))
+        print("vid", hex(device.idVendor))
+        print("man", device.manufacturer)
+        print("product", device.product)
+        print("serial", device.serial_number)
+        print("config[0]:")
+        config_descriptor = adafruit_usb_host_descriptors.get_configuration_descriptor(
+            device, 0
+        )
+
+        i = 0
+        while i < len(config_descriptor):
+            descriptor_len = config_descriptor[i]
+            descriptor_type = config_descriptor[i + 1]
+            if descriptor_type == adafruit_usb_host_descriptors.DESC_CONFIGURATION:
+                config_value = config_descriptor[i + 5]
+                print(f" value {config_value:d}")
+            elif descriptor_type == adafruit_usb_host_descriptors.DESC_INTERFACE:
+                interface_number = config_descriptor[i + 2]
+                interface_class = config_descriptor[i + 5]
+                interface_subclass = config_descriptor[i + 6]
+                print(f" interface[{interface_number:d}]")
+                print(
+                    f"  class {interface_class:02x} subclass {interface_subclass:02x}"
+                )
+            elif descriptor_type == adafruit_usb_host_descriptors.DESC_ENDPOINT:
+                endpoint_address = config_descriptor[i + 2]
+                if endpoint_address & DIR_IN:
+                    print(f"  IN {endpoint_address:02x}")
+                else:
+                    print(f"  OUT {endpoint_address:02x}")
+            i += descriptor_len
+
+# get the first device found
+device = None
+while device is None:
+    for d in usb.core.find(find_all=True):
+        device = d
+        break
+    time.sleep(0.1)
+
+# set configuration so we can read data from it
+device.set_configuration()
+print(
+    f"configuration set for {device.manufacturer}, {device.product}, {device.serial_number}"
+)
+
+# Test to see if the kernel is using the device and detach it.
+if device.is_kernel_driver_active(0):
+    device.detach_kernel_driver(0)
+
+# buffer to hold 64 bytes
+buf = array.array("B", [0] * 64)
+
+
+def print_array(arr, max_index=None, fmt="hex"):
+    """
+    Print the values of an array
+    :param arr: The array to print
+    :param max_index: The maximum index to print. None means print all.
+    :param fmt: The format to use, either "hex" or "bin"
+    :return: None
+    """
+    out_str = ""
+    if max_index is None or max_index >= len(arr):
+        length = len(arr)
+    else:
+        length = max_index
+
+    for _ in range(length):
+        if fmt == "hex":
+            out_str += f"{int(arr[_]):02x} "
+        elif fmt == "bin":
+            out_str += f"{int(arr[_]):08b} "
+    print(out_str)
+
+
+def reports_equal(report_a, report_b, check_length=None):
+    """
+    Test if two reports are equal. Accounting for any IGNORE_INDEXES
+
+    :param report_a: First report data
+    :param report_b: Second report data
+    :return: True if the reports are equal, otherwise False.
+    """
+    if (
+        report_a is None
+        and report_b is not None
+        or report_b is None
+        and report_a is not None
+    ):
+        return False
+
+    length = len(report_a) if check_length is None else check_length
+    for _ in range(length):
+        if report_a[_] != report_b[_]:
+            return False
+    return True
+
+
+def differing_indexes(report_a, report_b):
+    if (
+        report_a is None
+        and report_b is not None
+        or report_b is None
+        and report_a is not None
+    ):
+        return None
+    indexes = []
+    for _ in range(len(report_a)):
+        if report_a[_] != report_b[_]:
+            indexes.append(_)
+    return indexes
+
+
+idle_state = None
+prev_state = None
+
+while True:
+    try:
+        count = device.read(0x81, buf)
+        # print(f"read size: {count}")
+    except usb.core.USBTimeoutError:
+        continue
+
+    if idle_state is None:
+        idle_state = buf[:]
+        print("Idle state:")
+        print_array(idle_state[:8], max_index=count)
+        print()
+
+    if not reports_equal(buf, prev_state, 8) and not reports_equal(buf, idle_state, 8):
+        # print_array(buf, max_index=count)
+        # diff_indexes = differing_indexes(idle_state, buf)
+        # print(f"diff indexes: {diff_indexes}")
+
+        # for idx in diff_indexes:
+        #     print(f"{idx}: {idle_state[idx]} -> {buf[idx]}")
+        # print_array(buf)
+
+        if buf[BTN_DPAD_UPDOWN_INDEX] == 0x0:
+            print("D-Pad UP pressed")
+        elif buf[BTN_DPAD_UPDOWN_INDEX] == 0xFF:
+            print("D-Pad DOWN pressed")
+
+        if buf[BTN_DPAD_RIGHTLEFT_INDEX] == 0:
+            print("D-Pad LEFT pressed")
+        elif buf[BTN_DPAD_RIGHTLEFT_INDEX] == 0xFF:
+            print("D-Pad RIGHT pressed")
+
+        if buf[BTN_ABXY_INDEX] == 0x2F:
+            print("A pressed")
+        elif buf[BTN_ABXY_INDEX] == 0x4F:
+            print("B pressed")
+        elif buf[BTN_ABXY_INDEX] == 0x1F:
+            print("X pressed")
+        elif buf[BTN_ABXY_INDEX] == 0x8F:
+            print("Y pressed")
+
+        if buf[BTN_OTHER_INDEX] == 0x01:
+            print("L shoulder pressed")
+        elif buf[BTN_OTHER_INDEX] == 0x02:
+            print("R shoulder pressed")
+        elif buf[BTN_OTHER_INDEX] == 0x10:
+            print("SELECT pressed")
+        elif buf[BTN_OTHER_INDEX] == 0x20:
+            print("START pressed")
+
+        print_array(buf[:8])
+
+    prev_state = buf[:]