78 · konan-1947 · Oct 18, 2025
diff --git a/main/CMakeLists.txt b/main/CMakeLists.txt
@@ -8,6 +8,7 @@ set(SOURCES "audio/audio_codec.cc"
             "audio/codecs/es8388_audio_codec.cc"
             "audio/codecs/es8389_audio_codec.cc"
             "audio/codecs/dummy_audio_codec.cc"
+            "audio/codecs/max98357a_inmp441_codec.cc"
             "audio/processors/audio_debugger.cc"
             "led/single_led.cc"
             "led/circular_strip.cc"
@@ -192,6 +193,10 @@ elseif(CONFIG_BOARD_TYPE_XMINI_C3)
     set(BOARD_TYPE "xmini-c3")
     set(BUILTIN_TEXT_FONT font_puhui_basic_14_1)
     set(BUILTIN_ICON_FONT font_awesome_14_1)
+elseif(CONFIG_BOARD_TYPE_ESP32_C3_MINI_KONAN)
+    set(BOARD_TYPE "esp32-c3-mini-konan")
+    set(BUILTIN_TEXT_FONT font_puhui_basic_14_1)
+    set(BUILTIN_ICON_FONT font_awesome_14_1)
 elseif(CONFIG_BOARD_TYPE_ESP32S3_KORVO2_V3)
     set(BOARD_TYPE "esp32s3-korvo2-v3")
     set(BUILTIN_TEXT_FONT font_puhui_basic_20_4)
@@ -648,8 +653,8 @@ endif()
 
 file(GLOB COMMON_SOUNDS ${CMAKE_CURRENT_SOURCE_DIR}/assets/common/*.ogg)
 
-# If target chip is ESP32, exclude specific files to avoid build errors
-if(CONFIG_IDF_TARGET_ESP32)
+# If target chip is ESP32 or ESP32-C3, exclude specific files to avoid build errors
+if(CONFIG_IDF_TARGET_ESP32 OR CONFIG_IDF_TARGET_ESP32C3)
     list(REMOVE_ITEM SOURCES "audio/codecs/box_audio_codec.cc"
                              "audio/codecs/es8388_audio_codec.cc"
                              "audio/codecs/es8389_audio_codec.cc"

diff --git a/main/Kconfig.projbuild b/main/Kconfig.projbuild
@@ -144,6 +144,9 @@ choice BOARD_TYPE
     config BOARD_TYPE_XMINI_C3
         bool "Xmini C3"
         depends on IDF_TARGET_ESP32C3
+    config BOARD_TYPE_ESP32_C3_MINI_KONAN
+        bool "ESP32-C3 Mini Konan (MAX98357A + INMP441)"
+        depends on IDF_TARGET_ESP32C3
     config BOARD_TYPE_ESP32S3_KORVO2_V3
         bool "ESP32S3 KORVO2 V3"
         depends on IDF_TARGET_ESP32S3

diff --git a/main/audio/codecs/max98357a_inmp441_codec.cc b/main/audio/codecs/max98357a_inmp441_codec.cc
@@ -0,0 +1,196 @@
+#include "max98357a_inmp441_codec.h"
+#include <esp_log.h>
+#include <driver/i2s_std.h>
+
+#define TAG "Max98357aInmp441Codec"
+
+Max98357aInmp441Codec::Max98357aInmp441Codec(int input_sample_rate, int output_sample_rate,
+    gpio_num_t bclk, gpio_num_t ws, gpio_num_t dout, gpio_num_t din,
+    gpio_num_t sd_mode_pin) : sd_mode_pin_(sd_mode_pin) {
+
+    duplex_ = true;
+    input_reference_ = false;
+    input_channels_ = 1;
+    output_channels_ = 1;
+    input_sample_rate_ = input_sample_rate;
+    output_sample_rate_ = output_sample_rate;
+    input_gain_ = 0.0;
+
+    // Configure SD_MODE pin for MAX98357A if provided
+    if (sd_mode_pin_ != GPIO_NUM_NC) {
+        gpio_config_t io_conf = {};
+        io_conf.intr_type = GPIO_INTR_DISABLE;
+        io_conf.mode = GPIO_MODE_OUTPUT;
+        io_conf.pin_bit_mask = (1ULL << sd_mode_pin_);
+        io_conf.pull_down_en = GPIO_PULLDOWN_DISABLE;
+        io_conf.pull_up_en = GPIO_PULLUP_DISABLE;
+        gpio_config(&io_conf);
+        gpio_set_level(sd_mode_pin_, 1); // Enable MAX98357A
+    }
+
+    CreateDuplexChannels(bclk, ws, dout, din);
+    ESP_LOGI(TAG, "MAX98357A + INMP441 codec initialized");
+}
+
+Max98357aInmp441Codec::~Max98357aInmp441Codec() {
+    if (tx_handle_) {
+        i2s_channel_disable(tx_handle_);
+        i2s_del_channel(tx_handle_);
+    }
+    if (rx_handle_) {
+        i2s_channel_disable(rx_handle_);
+        i2s_del_channel(rx_handle_);
+    }
+
+    // Shutdown MAX98357A
+    if (sd_mode_pin_ != GPIO_NUM_NC) {
+        gpio_set_level(sd_mode_pin_, 0);
+    }
+}
+
+void Max98357aInmp441Codec::CreateDuplexChannels(gpio_num_t bclk, gpio_num_t ws, gpio_num_t dout, gpio_num_t din) {
+    // Create I2S channels for duplex operation
+    i2s_chan_config_t chan_cfg = {
+        .id = I2S_NUM_0,
+        .role = I2S_ROLE_MASTER,
+        .dma_desc_num = AUDIO_CODEC_DMA_DESC_NUM,
+        .dma_frame_num = AUDIO_CODEC_DMA_FRAME_NUM,
+        .auto_clear_after_cb = true,
+        .auto_clear_before_cb = false,
+        .intr_priority = 0,
+    };
+    ESP_ERROR_CHECK(i2s_new_channel(&chan_cfg, &tx_handle_, &rx_handle_));
+
+    // Configure TX (output to MAX98357A)
+    i2s_std_config_t tx_std_cfg = {
+        .clk_cfg = {
+            .sample_rate_hz = (uint32_t)output_sample_rate_,
+            .clk_src = I2S_CLK_SRC_DEFAULT,
+            .ext_clk_freq_hz = 0,
+            .mclk_multiple = I2S_MCLK_MULTIPLE_256
+        },
+        .slot_cfg = I2S_STD_PHILIPS_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, I2S_SLOT_MODE_MONO),
+        .gpio_cfg = {
+            .mclk = I2S_GPIO_UNUSED,
+            .bclk = bclk,
+            .ws = ws,
+            .dout = dout,
+            .din = I2S_GPIO_UNUSED,
+            .invert_flags = {
+                .mclk_inv = false,
+                .bclk_inv = false,
+                .ws_inv = false
+            }
+        }
+    };
+    ESP_ERROR_CHECK(i2s_channel_init_std_mode(tx_handle_, &tx_std_cfg));
+
+    // Configure RX (input from INMP441)
+    i2s_std_config_t rx_std_cfg = {
+        .clk_cfg = {
+            .sample_rate_hz = (uint32_t)input_sample_rate_,
+            .clk_src = I2S_CLK_SRC_DEFAULT,
+            .ext_clk_freq_hz = 0,
+            .mclk_multiple = I2S_MCLK_MULTIPLE_256
+        },
+        .slot_cfg = I2S_STD_PHILIPS_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_32BIT, I2S_SLOT_MODE_MONO),
+        .gpio_cfg = {
+            .mclk = I2S_GPIO_UNUSED,
+            .bclk = bclk,
+            .ws = ws,
+            .dout = I2S_GPIO_UNUSED,
+            .din = din,
+            .invert_flags = {
+                .mclk_inv = false,
+                .bclk_inv = false,
+                .ws_inv = false
+            }
+        }
+    };
+    ESP_ERROR_CHECK(i2s_channel_init_std_mode(rx_handle_, &rx_std_cfg));
+
+    ESP_LOGI(TAG, "Duplex I2S channels created");
+}
+
+void Max98357aInmp441Codec::SetOutputVolume(int volume) {
+    // MAX98357A doesn't support software volume control
+    // Volume is controlled by SD_MODE pin (3 levels) or external circuit
+    ESP_LOGW(TAG, "MAX98357A doesn't support software volume control");
+    AudioCodec::SetOutputVolume(volume);
+}
+
+void Max98357aInmp441Codec::EnableInput(bool enable) {
+    if (enable == input_enabled_) {
+        return;
+    }
+    if (enable) {
+        ESP_ERROR_CHECK(i2s_channel_enable(rx_handle_));
+        ESP_LOGI(TAG, "INMP441 input enabled");
+    } else {
+        ESP_ERROR_CHECK(i2s_channel_disable(rx_handle_));
+        ESP_LOGI(TAG, "INMP441 input disabled");
+    }
+    AudioCodec::EnableInput(enable);
+}
+
+void Max98357aInmp441Codec::EnableOutput(bool enable) {
+    if (enable == output_enabled_) {
+        return;
+    }
+    if (enable) {
+        ESP_ERROR_CHECK(i2s_channel_enable(tx_handle_));
+        if (sd_mode_pin_ != GPIO_NUM_NC) {
+            gpio_set_level(sd_mode_pin_, 1);
+        }
+        ESP_LOGI(TAG, "MAX98357A output enabled");
+    } else {
+        ESP_ERROR_CHECK(i2s_channel_disable(tx_handle_));
+        if (sd_mode_pin_ != GPIO_NUM_NC) {
+            gpio_set_level(sd_mode_pin_, 0);
+        }
+        ESP_LOGI(TAG, "MAX98357A output disabled");
+    }
+    AudioCodec::EnableOutput(enable);
+}
+
+int Max98357aInmp441Codec::Read(int16_t* dest, int samples) {
+    if (!input_enabled_) {
+        return 0;
+    }
+
+    size_t bytes_read = 0;
+    // INMP441 outputs 32-bit data, we need to convert to 16-bit
+    int32_t temp_buffer[AUDIO_CODEC_DMA_FRAME_NUM];
+    size_t bytes_to_read = samples * sizeof(int32_t);
+
+    esp_err_t ret = i2s_channel_read(rx_handle_, temp_buffer, bytes_to_read, &bytes_read, portMAX_DELAY);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "I2S read failed: %d", ret);
+        return 0;
+    }
+
+    // Convert 32-bit to 16-bit (take upper 16 bits)
+    int samples_read = bytes_read / sizeof(int32_t);
+    for (int i = 0; i < samples_read; i++) {
+        dest[i] = (int16_t)(temp_buffer[i] >> 16);
+    }
+
+    return samples_read;
+}
+
+int Max98357aInmp441Codec::Write(const int16_t* data, int samples) {
+    if (!output_enabled_) {
+        return 0;
+    }
+
+    size_t bytes_written = 0;
+    size_t bytes_to_write = samples * sizeof(int16_t);
+
+    esp_err_t ret = i2s_channel_write(tx_handle_, data, bytes_to_write, &bytes_written, portMAX_DELAY);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "I2S write failed: %d", ret);
+        return 0;
+    }
+
+    return bytes_written / sizeof(int16_t);
+}
diff --git a/main/audio/codecs/max98357a_inmp441_codec.h b/main/audio/codecs/max98357a_inmp441_codec.h
@@ -0,0 +1,27 @@
+#ifndef _MAX98357A_INMP441_CODEC_H
+#define _MAX98357A_INMP441_CODEC_H
+
+#include "audio_codec.h"
+#include <driver/gpio.h>
+
+class Max98357aInmp441Codec : public AudioCodec {
+private:
+    gpio_num_t sd_mode_pin_;
+
+    void CreateDuplexChannels(gpio_num_t bclk, gpio_num_t ws, gpio_num_t dout, gpio_num_t din);
+
+    virtual int Read(int16_t* dest, int samples) override;
+    virtual int Write(const int16_t* data, int samples) override;
+
+public:
+    Max98357aInmp441Codec(int input_sample_rate, int output_sample_rate,
+        gpio_num_t bclk, gpio_num_t ws, gpio_num_t dout, gpio_num_t din,
+        gpio_num_t sd_mode_pin = GPIO_NUM_NC);
+    virtual ~Max98357aInmp441Codec();
+
+    virtual void SetOutputVolume(int volume) override;
+    virtual void EnableInput(bool enable) override;
+    virtual void EnableOutput(bool enable) override;
+};
+
+#endif // _MAX98357A_INMP441_CODEC_H
diff --git a/main/boards/esp32-c3-mini-konan/config.h b/main/boards/esp32-c3-mini-konan/config.h
@@ -0,0 +1,30 @@
+#ifndef _BOARD_CONFIG_H_
+#define _BOARD_CONFIG_H_
+
+#include <driver/gpio.h>
+
+#define AUDIO_INPUT_SAMPLE_RATE  16000
+#define AUDIO_OUTPUT_SAMPLE_RATE 16000
+
+// I2S pins for MAX98357A (output) and INMP441 (input)
+#define AUDIO_I2S_GPIO_BCLK GPIO_NUM_4   // Bit Clock
+#define AUDIO_I2S_GPIO_WS   GPIO_NUM_5   // Word Select (LRC)
+#define AUDIO_I2S_GPIO_DOUT GPIO_NUM_6   // Data Out to MAX98357A
+#define AUDIO_I2S_GPIO_DIN  GPIO_NUM_7   // Data In from INMP441
+
+// MAX98357A gain control (optional, can be tied to VDD/GND for fixed gain)
+#define MAX98357A_SD_MODE_PIN GPIO_NUM_8  // Shutdown/Gain control
+
+// Built-in LED and button
+#define BUILTIN_LED_GPIO     GPIO_NUM_2
+#define BOOT_BUTTON_GPIO     GPIO_NUM_9
+
+// Display configuration (SSD1306 OLED)
+#define DISPLAY_I2C_SDA_PIN  GPIO_NUM_10
+#define DISPLAY_I2C_SCL_PIN  GPIO_NUM_3
+#define DISPLAY_WIDTH        128
+#define DISPLAY_HEIGHT       64
+#define DISPLAY_MIRROR_X     true
+#define DISPLAY_MIRROR_Y     true
+
+#endif // _BOARD_CONFIG_H_
diff --git a/main/boards/esp32-c3-mini-konan/config.json b/main/boards/esp32-c3-mini-konan/config.json
@@ -0,0 +1,32 @@
+{
+    "target": "esp32c3",
+    "builds": [
+        {
+            "name": "esp32-c3-mini-konan",
+            "sdkconfig_append": [
+                "CONFIG_PM_ENABLE=y",
+                "CONFIG_FREERTOS_USE_TICKLESS_IDLE=y",
+                "CONFIG_USE_ESP_WAKE_WORD=y",
+                "CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG=y",
+                "CONFIG_XIAOZHI_ENABLE_HARDWARE_JPEG_ENCODER=n",
+                "CONFIG_LVGL_USE_DRAW_SW=y",
+                "CONFIG_LVGL_USE_DRAW_VGLITE=n",
+                "CONFIG_LVGL_USE_DRAW_SDL=n",
+                "CONFIG_LVGL_USE_FREETYPE=n",
+                "CONFIG_SPIRAM=n",
+                "CONFIG_ESPTOOLPY_FLASHSIZE_4MB=y",
+                "CONFIG_PARTITION_TABLE_CUSTOM=y",
+                "CONFIG_PARTITION_TABLE_CUSTOM_FILENAME=\"main/boards/esp32-c3-mini-konan/partitions_4mb.csv\"",
+                "CONFIG_COMPILER_OPTIMIZATION_SIZE=y",
+                "CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_DISABLE=y",
+                "CONFIG_LOG_DEFAULT_LEVEL_INFO=y",
+                "CONFIG_BOOTLOADER_LOG_LEVEL_WARN=y",
+                "CONFIG_BT_ENABLED=n",
+                "CONFIG_BT_BLUEDROID_ENABLED=n",
+                "CONFIG_BT_NIMBLE_ENABLED=n",
+                "CONFIG_LWIP_IPV6=n",
+                "CONFIG_LWIP_NETIF_LOOPBACK=n"
+            ]
+        }
+    ]
+}