Added basic Espressif PDM microphone support #7454

locale/circuitpython.pot

@@ -2498,6 +2498,10 @@ msgstr ""
 msgid "binary op %q not implemented"
 msgstr ""
 
+#: ports/espressif/common-hal/audiobusio/PDMIn.c
+msgid "bit_depth must be 8, 16, 24, or 32."
+msgstr ""
+
 #: shared-module/bitmapfilter/__init__.c
 msgid "bitmap size and depth must match"
 msgstr ""
@@ -2592,7 +2596,7 @@ msgstr ""
 msgid "can't cancel self"
 msgstr ""
 
-#: shared-module/adafruit_pixelbuf/PixelBuf.c
+#: py/obj.c shared-module/adafruit_pixelbuf/PixelBuf.c
 msgid "can't convert %q to %q"
 msgstr ""
 

ports/espressif/common-hal/audiobusio/PDMIn.c

@@ -3,3 +3,129 @@
 // SPDX-FileCopyrightText: Copyright (c) 2024 Adafruit Industries LLC
 //
 // SPDX-License-Identifier: MIT
+
+
+#include "bindings/espidf/__init__.h"
+
+#include "common-hal/audiobusio/PDMIn.h"
+#include "py/mpprint.h"
+#include "py/runtime.h"
+#include "shared-bindings/audiobusio/PDMIn.h"
+
+
+#include "driver/i2s_pdm.h"
+
+
+
+#if CIRCUITPY_AUDIOBUSIO_PDMIN
+
+
+
+/**
+	Note: I think this function needs an additional parameter for the word select
+	pin. It takes `mono`, a boolean indicating if it should be mono or
+	stereo, but without a word select pin, I don't think one can get
+	the other channel.
+*/
+
+void common_hal_audiobusio_pdmin_construct(audiobusio_pdmin_obj_t *self,
+    const mcu_pin_obj_t *clock_pin,
+    const mcu_pin_obj_t *data_pin,
+    uint32_t sample_rate,
+    uint8_t bit_depth,
+    bool mono,
+    uint8_t oversample) {
+
+    if (bit_depth != I2S_DATA_BIT_WIDTH_8BIT
+        && bit_depth != I2S_DATA_BIT_WIDTH_16BIT
+        && bit_depth != I2S_DATA_BIT_WIDTH_24BIT
+        && bit_depth != I2S_DATA_BIT_WIDTH_32BIT) {
+        mp_raise_ValueError(MP_ERROR_TEXT("bit_depth must be 8, 16, 24, or 32."));
+    }
+
+    i2s_chan_config_t chanConfig = I2S_CHANNEL_DEFAULT_CONFIG(I2S_NUM_0, I2S_ROLE_MASTER);
+    esp_err_t err = i2s_new_channel(&chanConfig, NULL, &self->rx_chan);
+    CHECK_ESP_RESULT(err);
+
+    i2s_pdm_rx_config_t pdm_rx_cfg = {
+        .clk_cfg = I2S_PDM_RX_CLK_DEFAULT_CONFIG(sample_rate),
+        .slot_cfg = I2S_PDM_RX_SLOT_DEFAULT_CONFIG(bit_depth, mono ? I2S_SLOT_MODE_MONO : I2S_SLOT_MODE_STEREO),
+        .gpio_cfg =
+        {
+            .clk = clock_pin->number,
+            .din = data_pin->number,
+            .invert_flags =
+            {
+                .clk_inv = false,
+            },
+        },
+    };
+    err = i2s_channel_init_pdm_rx_mode(self->rx_chan, &pdm_rx_cfg);
+    CHECK_ESP_RESULT(err);
+
+    err = i2s_channel_enable(self->rx_chan);
+    CHECK_ESP_RESULT(err);
+
+    self->clock_pin = clock_pin;
+    self->data_pin = data_pin;
+    claim_pin(clock_pin);
+    claim_pin(data_pin);
+
+    self->sample_rate = sample_rate;
+    self->bit_depth = bit_depth;
+}
+
+bool common_hal_audiobusio_pdmin_deinited(audiobusio_pdmin_obj_t *self) {
+    return self->clock_pin == NULL;
+}
+
+void common_hal_audiobusio_pdmin_deinit(audiobusio_pdmin_obj_t *self) {
+    mp_printf(MP_PYTHON_PRINTER, "Deinit\n");
+    if (common_hal_audiobusio_pdmin_deinited(self)) {
+        mp_printf(MP_PYTHON_PRINTER, "Already deinitted, bailing\n");
+        return;
+    }
+
+    esp_err_t err = i2s_channel_disable(self->rx_chan);
+    CHECK_ESP_RESULT(err);
+    err = i2s_del_channel(self->rx_chan);
+    CHECK_ESP_RESULT(err);
+
+    // common_hal_audiobusio_i2sout_stop(self);
+
+    if (self->clock_pin) {
+        reset_pin_number(self->clock_pin->number);
+    }
+    self->clock_pin = NULL;
+
+    if (self->data_pin) {
+        reset_pin_number(self->data_pin->number);
+    }
+    self->data_pin = NULL;
+}
+
+/**
+	`length` is the buffer element count, not the byte count.
+*/
+
+uint32_t common_hal_audiobusio_pdmin_record_to_buffer(audiobusio_pdmin_obj_t *self,
+    uint16_t *buffer,
+    uint32_t length) {
+//      mp_printf(MP_PYTHON_PRINTER, "Copying bytes to buffer\n");
+
+    size_t result = 0;
+    size_t elementSize = common_hal_audiobusio_pdmin_get_bit_depth(self) / 8;
+    esp_err_t err = i2s_channel_read(self->rx_chan, buffer, length * elementSize, &result, 100);
+    CHECK_ESP_RESULT(err);
+    return result;
+}
+
+uint8_t common_hal_audiobusio_pdmin_get_bit_depth(audiobusio_pdmin_obj_t *self) {
+    return self->bit_depth;
+}
+
+uint32_t common_hal_audiobusio_pdmin_get_sample_rate(audiobusio_pdmin_obj_t *self) {
+    return self->sample_rate;
+}
+
+#endif

ports/espressif/common-hal/audiobusio/PDMIn.h

@@ -5,3 +5,21 @@
 // SPDX-License-Identifier: MIT
 
 #pragma once
+
+#include "py/obj.h"
+
+#include "common-hal/audiobusio/__init__.h"
+#include "common-hal/microcontroller/Pin.h"
+
+#if CIRCUITPY_AUDIOBUSIO_PDMIN
+
+typedef struct {
+    i2s_t i2s;
+    i2s_chan_handle_t rx_chan;
+    const mcu_pin_obj_t *clock_pin;
+    const mcu_pin_obj_t *data_pin;
+    uint32_t sample_rate;
+    uint8_t bit_depth;
+} audiobusio_pdmin_obj_t;
+
+#endif

ports/espressif/mpconfigport.mk

@@ -230,6 +230,7 @@ CIRCUITPY_ESP_USB_SERIAL_JTAG ?= 0
 else ifeq ($(IDF_TARGET),esp32s3)
 # Modules
 CIRCUITPY_ALARM_TOUCH = 1
+CIRCUITPY_AUDIOBUSIO_PDMIN = 1
 CIRCUITPY_ESP_USB_SERIAL_JTAG ?= 0
 
 # No room for _bleio on boards with 4MB flash

shared-bindings/audiobusio/PDMIn.c

@@ -95,7 +95,7 @@ static mp_obj_t audiobusio_pdmin_make_new(const mp_obj_type_t *type, size_t n_ar
     const mcu_pin_obj_t *data_pin = validate_obj_is_free_pin(args[ARG_data_pin].u_obj, MP_QSTR_data_pin);
 
     // create PDMIn object from the given pin
-    audiobusio_pdmin_obj_t *self = mp_obj_malloc(audiobusio_pdmin_obj_t, &audiobusio_pdmin_type);
+    audiobusio_pdmin_obj_t *self = mp_obj_malloc_with_finaliser(audiobusio_pdmin_obj_t, &audiobusio_pdmin_type);
 
     uint32_t sample_rate = args[ARG_sample_rate].u_int;
     uint8_t bit_depth = args[ARG_bit_depth].u_int;
@@ -210,6 +210,7 @@ MP_PROPERTY_GETTER(audiobusio_pdmin_sample_rate_obj,
 
 static const mp_rom_map_elem_t audiobusio_pdmin_locals_dict_table[] = {
     // Methods
+    { MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&audiobusio_pdmin_deinit_obj) },
     { 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) },