circuitpython/shared-bindings/audiobusio/PDMIn.c

/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include <stdint.h>

#include "lib/utils/context_manager_helpers.h"
#include "py/binary.h"
#include "py/mphal.h"
#include "py/objproperty.h"
#include "py/runtime.h"
#include "shared-bindings/microcontroller/Pin.h"
#include "shared-bindings/audiobusio/PDMIn.h"
#include "shared-bindings/util.h"

//| .. currentmodule:: audiobusio
//|
//| :class:`PDMIn` -- Record an input PDM audio stream
//| ========================================================
//|
//| PDMIn can be used to record an input audio signal on a given set of pins.
//|
//| .. class:: PDMIn(clock_pin, data_pin, \*, frequency=16000, bit_depth=8, mono=True, oversample=64, startup_delay=0.11)
//|
//|   Create a PDMIn object associated with the given pins. This allows you to
//|   record audio signals from the given pins. Individual ports may put further
//|   restrictions on the recording parameters. The overall frequency is
//|   determined by `frequency` x ``oversample``, and the total must be 1MHz or
//|   higher, so `frequency` must be a minimum of 16000.
//|
//|   :param ~microcontroller.Pin clock_pin: The pin to output the clock to
//|   :param ~microcontroller.Pin data_pin: The pin to read the data from
//|   :param int frequency: Target frequency of the resulting samples. Check `frequency` for actual value.
//|     Minimum frequency is about 16000 Hz.
//|   :param int bit_depth: Final number of bits per sample. Must be divisible by 8
//|   :param bool mono: True when capturing a single channel of audio, captures two channels otherwise
//|   :param int oversample: Number of single bit samples to decimate into a final sample. Must be divisible by 8
//|   :param float startup_delay: seconds to wait after starting microphone clock
//|    to allow microphone to turn on. Most require only 0.01s; some require 0.1s. Longer is safer.
//|    Must be in range 0.0-1.0 seconds.
//|

//|   Record 8-bit unsigned samples to buffer::
//|
//|     import audiobusio
//|     import board
//|
//|     # Prep a buffer to record into
//|     b = bytearray(200)
//|     with audiobusio.PDMIn(board.MICROPHONE_CLOCK, board.MICROPHONE_DATA, frequency=16000) as mic:
//|         mic.record(b, len(b))
//|
//|   Record 16-bit unsigned samples to buffer::
//|
//|     import audiobusio
//|     import board
//|
//|     # Prep a buffer to record into. The array interface doesn't allow for
//|     # constructing with a set size so we append to it until we have the size
//|     # we want.
//|     b = array.array("H")
//|     for i in range(200):
//|         b.append(0)
//|     with audiobusio.PDMIn(board.MICROPHONE_CLOCK, board.MICROPHONE_DATA, frequency=16000, bit_depth=16) as mic:
//|         mic.record(b, len(b))
//|
STATIC mp_obj_t audiobusio_pdmin_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *pos_args) {
    enum { ARG_frequency, ARG_bit_depth, ARG_mono, ARG_oversample, ARG_startup_delay };
    mp_map_t kw_args;
    mp_map_init_fixed_table(&kw_args, n_kw, pos_args + n_args);
    static const mp_arg_t allowed_args[] = {
        { MP_QSTR_frequency,     MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 16000} },
        { MP_QSTR_bit_depth,     MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} },
        { MP_QSTR_mono,          MP_ARG_KW_ONLY | MP_ARG_BOOL,{.u_bool = true} },
        { MP_QSTR_oversample,    MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 64} },
        { MP_QSTR_startup_delay, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
    };
    // Default microphone startup delay is 110msecs. Have seen mics that need 100 msecs plus a bit.
    static const float STARTUP_DELAY_DEFAULT = 0.110F;

    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
    mp_arg_parse_all(n_args - 2, pos_args + 2, &kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);

    mp_obj_t clock_pin_obj = pos_args[0];
    assert_pin(clock_pin_obj, false);
    const mcu_pin_obj_t *clock_pin = MP_OBJ_TO_PTR(clock_pin_obj);
    assert_pin_free(clock_pin);

    mp_obj_t data_pin_obj = pos_args[1];
    assert_pin(data_pin_obj, false);
    const mcu_pin_obj_t *data_pin = MP_OBJ_TO_PTR(data_pin_obj);
    assert_pin_free(data_pin);

    // create PDMIn object from the given pin
    audiobusio_pdmin_obj_t *self = m_new_obj(audiobusio_pdmin_obj_t);
    self->base.type = &audiobusio_pdmin_type;

    uint32_t frequency = args[ARG_frequency].u_int;
    uint8_t bit_depth = args[ARG_bit_depth].u_int;
    if (bit_depth % 8 != 0) {
        mp_raise_ValueError("Bit depth must be multiple of 8.");
    }
    uint8_t oversample = args[ARG_oversample].u_int;
    if (oversample % 8 != 0) {
        mp_raise_ValueError("Oversample must be multiple of 8.");
    }
    bool mono = args[ARG_mono].u_bool;

    float startup_delay = (args[ARG_startup_delay].u_obj == MP_OBJ_NULL)
        ? STARTUP_DELAY_DEFAULT
        : mp_obj_get_float(args[ARG_startup_delay].u_obj);
    if (startup_delay < 0.0 || startup_delay > 1.0) {
        mp_raise_ValueError("Microphone startup delay must be in range 0.0 to 1.0");
    }

    common_hal_audiobusio_pdmin_construct(self, clock_pin, data_pin, frequency,
                                          bit_depth, mono, oversample);

    // Wait for the microphone to start up. Some start in 10 msecs; some take as much as 100 msecs.
    mp_hal_delay_ms(startup_delay * 1000);

    return MP_OBJ_FROM_PTR(self);
}

//|   .. method:: deinit()
//|
//|      Deinitialises the PDMIn and releases any hardware resources for reuse.
//|
STATIC mp_obj_t audiobusio_pdmin_deinit(mp_obj_t self_in) {
    audiobusio_pdmin_obj_t *self = MP_OBJ_TO_PTR(self_in);
    common_hal_audiobusio_pdmin_deinit(self);
    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(audiobusio_pdmin_deinit_obj, audiobusio_pdmin_deinit);

//|   .. method:: __enter__()
//|
//|      No-op used by Context Managers.
//|
//  Provided by context manager helper.

//|   .. method:: __exit__()
//|
//|      Automatically deinitializes the hardware when exiting a context.
//|
STATIC mp_obj_t audiobusio_pdmin_obj___exit__(size_t n_args, const mp_obj_t *args) {
    (void)n_args;
    common_hal_audiobusio_pdmin_deinit(args[0]);
    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(audiobusio_pdmin___exit___obj, 4, 4, audiobusio_pdmin_obj___exit__);


//|   .. method:: record(destination, destination_length)
//|
//|     Records destination_length bytes of samples to destination. This is
//|     blocking.
//|
//|     An IOError may be raised when the destination is too slow to record the
//|     audio at the given rate. For internal flash, writing all 1s to the file
//|     before recording is recommended to speed up writes.
//|
//|     :return: The number of samples recorded. If this is less than ``destination_length``,
//|       some samples were missed due to processing time.
//|
STATIC mp_obj_t audiobusio_pdmin_obj_record(mp_obj_t self_obj, mp_obj_t destination, mp_obj_t destination_length) {
    audiobusio_pdmin_obj_t *self = MP_OBJ_TO_PTR(self_obj);
    raise_error_if_deinited(common_hal_audiobusio_pdmin_deinited(self));
    if (!MP_OBJ_IS_SMALL_INT(destination_length) || MP_OBJ_SMALL_INT_VALUE(destination_length) < 0) {
        mp_raise_TypeError("destination_length must be an int >= 0");
    }
    uint32_t length = MP_OBJ_SMALL_INT_VALUE(destination_length);

    mp_buffer_info_t bufinfo;
    if (MP_OBJ_IS_TYPE(destination, &fatfs_type_fileio)) {
        mp_raise_NotImplementedError("");
    } else if (mp_get_buffer(destination, &bufinfo, MP_BUFFER_WRITE)) {
        if (bufinfo.len / mp_binary_get_size('@', bufinfo.typecode, NULL) < length) {
            mp_raise_ValueError("Destination capacity is smaller than destination_length.");
        }
        uint8_t bit_depth = common_hal_audiobusio_pdmin_get_bit_depth(self);
        if (bufinfo.typecode != 'H' && bit_depth == 16) {
            mp_raise_ValueError("destination buffer must be an array of type 'H' for bit_depth = 16");
        } else if (bufinfo.typecode != 'B' && bufinfo.typecode != BYTEARRAY_TYPECODE && bit_depth == 8) {
            mp_raise_ValueError("destination buffer must be a bytearray or array of type 'B' for bit_depth = 8");
        }
        // length is the buffer length in slots, not bytes.
        uint32_t length_written =
            common_hal_audiobusio_pdmin_record_to_buffer(self, bufinfo.buf, length);
        return MP_OBJ_NEW_SMALL_INT(length_written);
    }
    return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_3(audiobusio_pdmin_record_obj, audiobusio_pdmin_obj_record);

//|   .. attribute:: frequency
//|
//|     The actual frequency of the recording. This may not match the constructed
//|     frequency due to internal clock limitations.
//|
STATIC mp_obj_t audiobusio_pdmin_obj_get_frequency(mp_obj_t self_in) {
    audiobusio_pdmin_obj_t *self = MP_OBJ_TO_PTR(self_in);
    raise_error_if_deinited(common_hal_audiobusio_pdmin_deinited(self));
    return MP_OBJ_NEW_SMALL_INT(common_hal_audiobusio_pdmin_get_frequency(self));
}
MP_DEFINE_CONST_FUN_OBJ_1(audiobusio_pdmin_get_frequency_obj, audiobusio_pdmin_obj_get_frequency);

const mp_obj_property_t audiobusio_pdmin_frequency_obj = {
    .base.type = &mp_type_property,
    .proxy = {(mp_obj_t)&audiobusio_pdmin_get_frequency_obj,
              (mp_obj_t)&mp_const_none_obj,
              (mp_obj_t)&mp_const_none_obj},
};

STATIC const mp_rom_map_elem_t audiobusio_pdmin_locals_dict_table[] = {
    // Methods
    { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&audiobusio_pdmin_deinit_obj) },
    { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
    { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&audiobusio_pdmin___exit___obj) },
    { MP_ROM_QSTR(MP_QSTR_record), MP_ROM_PTR(&audiobusio_pdmin_record_obj) },
    { MP_ROM_QSTR(MP_QSTR_frequency), MP_ROM_PTR(&audiobusio_pdmin_frequency_obj) }
};
STATIC MP_DEFINE_CONST_DICT(audiobusio_pdmin_locals_dict, audiobusio_pdmin_locals_dict_table);

const mp_obj_type_t audiobusio_pdmin_type = {
    { &mp_type_type },
    .name = MP_QSTR_PDMIn,
    .make_new = audiobusio_pdmin_make_new,
    .locals_dict = (mp_obj_dict_t*)&audiobusio_pdmin_locals_dict,
};