circuitpython/shared-bindings/keypad/Keys.c

// This file is part of the CircuitPython project: https://circuitpython.org
//
// SPDX-FileCopyrightText: Copyright (c) 2021 Dan Halbert for Adafruit Industries
//
// SPDX-License-Identifier: MIT

#include "shared/runtime/context_manager_helpers.h"
#include "py/binary.h"
#include "py/objproperty.h"
#include "py/runtime.h"
#include "shared-bindings/keypad/__init__.h"
#include "shared-bindings/keypad/Event.h"
#include "shared-bindings/keypad/Keys.h"
#include "shared-bindings/microcontroller/Pin.h"
#include "shared-bindings/util.h"

//| class Keys:
//|     """Manage a set of independent keys.
//|
//|     .. raw:: html
//|
//|         <p>
//|         <details>
//|         <summary>Available on these boards</summary>
//|         <ul>
//|         {% for board in support_matrix_reverse["keypad.Keys"] %}
//|         <li> {{ board }}
//|         {% endfor %}
//|         </ul>
//|         </details>
//|         </p>
//|
//|     """
//|
//|     def __init__(
//|         self,
//|         pins: Sequence[microcontroller.Pin],
//|         *,
//|         value_when_pressed: bool,
//|         pull: bool = True,
//|         interval: float = 0.020,
//|         max_events: int = 64,
//|         debounce_threshold: int = 1,
//|     ) -> None:
//|         """
//|         Create a `Keys` object that will scan keys attached to the given sequence of pins.
//|         Each key is independent and attached to its own pin.
//|
//|         An `EventQueue` is created when this object is created and is available in the `events` attribute.
//|
//|         :param Sequence[microcontroller.Pin] pins: The pins attached to the keys.
//|           The key numbers correspond to indices into this sequence.
//|         :param bool value_when_pressed: ``True`` if the pin reads high when the key is pressed.
//|           ``False`` if the pin reads low (is grounded) when the key is pressed.
//|           All the pins must be connected in the same way.
//|         :param bool pull: ``True`` if an internal pull-up or pull-down should be
//|           enabled on each pin. A pull-up will be used if ``value_when_pressed`` is ``False``;
//|           a pull-down will be used if it is ``True``.
//|           If an external pull is already provided for all the pins, you can set ``pull`` to ``False``.
//|           However, enabling an internal pull when an external one is already present is not a problem;
//|           it simply uses slightly more current.
//|         :param float interval: Scan keys no more often than ``interval`` to allow for debouncing.
//|           ``interval`` is in float seconds. The default is 0.020 (20 msecs).
//|         :param int max_events: maximum size of `events` `EventQueue`:
//|           maximum number of key transition events that are saved.
//|           Must be >= 1.
//|           If a new event arrives when the queue is full, the oldest event is discarded.
//|         :param int debounce_threshold: Emit events for state changes only after a key has been
//|           in the respective state for ``debounce_threshold`` times on average.
//|           Successive measurements are spaced apart by ``interval`` seconds.
//|           The default is 1, which resolves immediately. The maximum is 127.
//|
//|         .. warning:: On Raspberry Pi RP2350, using ``value_when_pressed=True`` and ``pull=True``,
//|            to enable using the internal pull-down resistor, will not work, due to an RP2350
//|            hardware issue. Instead, wire the switch to be ``value_when_pressed=False``, or add
//|            an external pull-down resistor of 8.2 kohms or less.
//|            See the Warning in `digitalio` for more information.
//|         """
//|         ...
//|

static mp_obj_t keypad_keys_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
    #if CIRCUITPY_KEYPAD_KEYS
    keypad_keys_obj_t *self = mp_obj_malloc(keypad_keys_obj_t, &keypad_keys_type);
    enum { ARG_pins, ARG_value_when_pressed, ARG_pull, ARG_interval, ARG_max_events, ARG_debounce_threshold };
    static const mp_arg_t allowed_args[] = {
        { MP_QSTR_pins, MP_ARG_REQUIRED | MP_ARG_OBJ },
        { MP_QSTR_value_when_pressed, MP_ARG_REQUIRED | MP_ARG_KW_ONLY | MP_ARG_BOOL },
        { MP_QSTR_pull, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} },
        { MP_QSTR_interval, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL } },
        { MP_QSTR_max_events, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 64} },
        { MP_QSTR_debounce_threshold, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
    };
    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
    mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);

    mp_obj_t pins = args[ARG_pins].u_obj;
    validate_no_duplicate_pins(pins, MP_QSTR_row_pins);
    // mp_obj_len() will be >= 0.
    const size_t num_pins = (size_t)MP_OBJ_SMALL_INT_VALUE(mp_obj_len(pins));

    const bool value_when_pressed = args[ARG_value_when_pressed].u_bool;
    const mp_float_t interval =
        mp_arg_validate_obj_float_non_negative(args[ARG_interval].u_obj, 0.020f, MP_QSTR_interval);
    const size_t max_events = (size_t)mp_arg_validate_int_min(args[ARG_max_events].u_int, 1, MP_QSTR_max_events);
    const uint8_t debounce_threshold = (uint8_t)mp_arg_validate_int_range(args[ARG_debounce_threshold].u_int, 1, 127, MP_QSTR_debounce_threshold);

    const mcu_pin_obj_t *pins_array[num_pins];

    for (mp_uint_t i = 0; i < num_pins; i++) {
        pins_array[i] =
            validate_obj_is_free_pin(mp_obj_subscr(pins, MP_OBJ_NEW_SMALL_INT(i), MP_OBJ_SENTINEL), MP_QSTR_pin);
    }

    common_hal_keypad_keys_construct(self, num_pins, pins_array, value_when_pressed, args[ARG_pull].u_bool, interval, max_events, debounce_threshold);

    return MP_OBJ_FROM_PTR(self);
    #else
    mp_raise_NotImplementedError_varg(MP_ERROR_TEXT("%q"), MP_QSTR_Keys);

    #endif
}

#if CIRCUITPY_KEYPAD_KEYS
//|     def deinit(self) -> None:
//|         """Stop scanning and release the pins."""
//|         ...
//|
static mp_obj_t keypad_keys_deinit(mp_obj_t self_in) {
    keypad_keys_obj_t *self = MP_OBJ_TO_PTR(self_in);

    common_hal_keypad_keys_deinit(self);
    return MP_ROM_NONE;
}
MP_DEFINE_CONST_FUN_OBJ_1(keypad_keys_deinit_obj, keypad_keys_deinit);

//|     def __enter__(self) -> Keys:
//|         """No-op used by Context Managers."""
//|         ...
//|
//  Provided by context manager helper.

//|     def __exit__(self) -> None:
//|         """Automatically deinitializes when exiting a context. See
//|         :ref:`lifetime-and-contextmanagers` for more info."""
//|         ...
//|
//  Provided by context manager helper.


//|     def reset(self) -> None:
//|         """Reset the internal state of the scanner to assume that all keys are now released.
//|         Any key that is already pressed at the time of this call will therefore immediately cause
//|         a new key-pressed event to occur.
//|         For instance, if you call `reset()` immediately after creating a `Keys` object
//|         at the beginning of your program, the events it generates will let you determine which keys
//|         were being held down at program start.
//|         """
//|         ...
//|

//|     key_count: int
//|     """The number of keys that are being scanned. (read-only)
//|     """

//|     events: EventQueue
//|     """The `EventQueue` associated with this `Keys` object. (read-only)
//|     """
//|
//|
static const mp_rom_map_elem_t keypad_keys_locals_dict_table[] = {
    { MP_ROM_QSTR(MP_QSTR_deinit),       MP_ROM_PTR(&keypad_keys_deinit_obj) },
    { MP_ROM_QSTR(MP_QSTR___enter__),    MP_ROM_PTR(&default___enter___obj) },
    { MP_ROM_QSTR(MP_QSTR___exit__),     MP_ROM_PTR(&default___exit___obj) },

    { MP_ROM_QSTR(MP_QSTR_events),       MP_ROM_PTR(&keypad_generic_events_obj) },
    { MP_ROM_QSTR(MP_QSTR_key_count),    MP_ROM_PTR(&keypad_generic_key_count_obj) },
    { MP_ROM_QSTR(MP_QSTR_reset),        MP_ROM_PTR(&keypad_generic_reset_obj) },
};

static MP_DEFINE_CONST_DICT(keypad_keys_locals_dict, keypad_keys_locals_dict_table);
#endif

MP_DEFINE_CONST_OBJ_TYPE(
    keypad_keys_type,
    MP_QSTR_Keys,
    MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS,
    make_new, keypad_keys_make_new
    #if CIRCUITPY_KEYPAD_KEYS
    , locals_dict, &keypad_keys_locals_dict
    #endif
    );