Moved software into seperate folder

software/.gitignore

@@ -0,0 +1,4 @@
+tools
+build
+.cache
+sdkconfig.old

software/CMakeLists.txt

@@ -0,0 +1,8 @@
+# For more information about build system see
+# https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/build-system.html
+# The following five lines of boilerplate have to be in your project's
+# CMakeLists in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.5)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(main)

software/main/CMakeLists.txt

@@ -0,0 +1,3 @@
+idf_component_register(SRCS "src/main.cpp" "src/helper.cpp" "src/wav.cpp" "src/storage.cpp" "src/i2s.cpp" "src/bluetooth.cpp" "src/avrcp.cpp" "src/a2dp.cpp"
+                    INCLUDE_DIRS "include"
+                    EMBED_FILES "assets/connect.wav" "assets/disconnect.wav")

software/main/include/a2dp.h

@@ -0,0 +1,7 @@
+#pragma once
+#include <cstdint>
+
+namespace a2dp {
+	void init();
+	void connect_to_last();
+}

software/main/include/avrcp.h

@@ -0,0 +1,5 @@
+#pragma once
+
+namespace avrcp {
+	void init();
+}

software/main/include/bluetooth.h

@@ -0,0 +1,6 @@
+#pragma once
+
+namespace bluetooth {
+	void init();
+	void set_scan_mode(bool connectable);
+}

software/main/include/helper.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include "esp_bt_device.h"
+#include "esp_a2dp_api.h"
+
+const char* addr_to_str(esp_bd_addr_t bda);
+const char* connection_state_to_str(esp_a2d_connection_state_t state);
+

software/main/include/i2s.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <cstdint>
+
+#define I2S_PORT I2S_NUM_0
+
+namespace i2s {
+	void init();
+
+	uint32_t get_sample_rate();
+	void set_sample_rate(uint32_t sample_rate);
+}

software/main/include/storage.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include "esp_bt_device.h"
+
+namespace nvs {
+	void init();
+
+	void get_last_connection(esp_bd_addr_t last_connection);
+	void set_last_connection(esp_bd_addr_t last_connection);
+	bool has_last_connection();
+}

software/main/include/wav.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <cstdint>
+
+#define WAV_PLAY_HELPER(str) #str
+#define WAV_PLAY(NAME) {\
+	extern const uint8_t _binary_ ## NAME ## _wav_start[]; \
+	extern const uint8_t _binary_ ## NAME ## _wav_end[]; \
+	wav::play(_binary_ ## NAME ## _wav_start, _binary_ ## NAME ## _wav_end); \
+}
+
+namespace wav {
+	void play(const uint8_t* start, const uint8_t* end);
+}

software/main/src/a2dp.cpp

@@ -0,0 +1,168 @@
+#include "esp_log.h"
+#include "esp_gap_bt_api.h"
+#include "esp_a2dp_api.h"
+#include "driver/i2s.h"
+
+#include "a2dp.h"
+#include "helper.h"
+#include "wav.h"
+#include "storage.h"
+#include "i2s.h"
+#include "bluetooth.h"
+
+#define A2DP_TAG "APP_A2DP"
+
+static void handle_connection_state(uint16_t event, esp_a2d_cb_param_t* a2d) {
+	ESP_LOGI(A2DP_TAG, "partner address: %s", addr_to_str(a2d->conn_stat.remote_bda));
+
+	ESP_LOGI(A2DP_TAG, "A2DP connection state: %s, [%s]", connection_state_to_str(a2d->conn_stat.state), addr_to_str(a2d->conn_stat.remote_bda));
+
+	static int retry_count = 0;
+	static bool was_connected = false;
+	if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_DISCONNECTED) {
+		ESP_LOGI(A2DP_TAG, "ESP_A2D_CONNECTION_STATE_DISCONNECTED");
+
+		if (a2d->conn_stat.disc_rsn == ESP_A2D_DISC_RSN_ABNORMAL && retry_count < 3) {
+				ESP_LOGI(A2DP_TAG,"Connection try number: %d", retry_count);
+
+				a2dp::connect_to_last();
+		} else {
+			bluetooth::set_scan_mode(true);
+
+			if (was_connected) {
+				vTaskDelay(300 / portTICK_PERIOD_MS);
+				WAV_PLAY(disconnect);
+			}
+		}
+	} else if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_CONNECTED){
+		ESP_LOGI(A2DP_TAG, "ESP_A2D_CONNECTION_STATE_CONNECTED");
+
+		bluetooth::set_scan_mode(false);
+		retry_count = 0;
+		was_connected = true;
+
+		WAV_PLAY(connect);
+
+		// record current connection
+		nvs::set_last_connection(a2d->conn_stat.remote_bda);
+		if (esp_bt_gap_read_remote_name(a2d->conn_stat.remote_bda) != ESP_OK) {
+			ESP_LOGE(A2DP_TAG, "esp_bt_gap_read_remote_name failed");
+		}
+	} else if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_CONNECTING){
+		ESP_LOGI(A2DP_TAG, "ESP_A2D_CONNECTION_STATE_CONNECTING");
+		retry_count++;
+	}
+}
+
+static void handle_audio_cfg(uint16_t event, esp_a2d_cb_param_t* a2d) {
+	ESP_LOGI(A2DP_TAG, "a2dp audio_cfg_cb , codec type %d", a2d->audio_cfg.mcc.type);
+
+	char oct0 = a2d->audio_cfg.mcc.cie.sbc[0];
+	if (oct0 & (0x01 << 6)) {
+		i2s::set_sample_rate(32000);
+	} else if (oct0 & (0x01 << 5)) {
+		i2s::set_sample_rate(44100);
+	} else if (oct0 & (0x01 << 4)) {
+		i2s::set_sample_rate(48000);
+	} else {
+		i2s::set_sample_rate(16000);
+	}
+
+	ESP_LOGI(A2DP_TAG, "a2dp audio_cfg_cb , sample_rate %d", i2s::get_sample_rate());
+}
+
+static void a2d_callback(esp_a2d_cb_event_t event, esp_a2d_cb_param_t* a2d) {
+	switch (event) {
+		case ESP_A2D_CONNECTION_STATE_EVT:
+			ESP_LOGD(A2DP_TAG, "%s ESP_A2D_CONNECTION_STATE_EVT", __func__);
+			handle_connection_state(event, a2d);
+			break;
+
+		case ESP_A2D_AUDIO_STATE_EVT:
+			ESP_LOGD(A2DP_TAG, "%s ESP_A2D_AUDIO_STATE_EVT", __func__);
+			break;
+
+		case ESP_A2D_AUDIO_CFG_EVT:
+			ESP_LOGD(A2DP_TAG, "%s ESP_A2D_AUDIO_CFG_EVT", __func__);
+			handle_audio_cfg(event, a2d);
+			break;
+
+		case ESP_A2D_PROF_STATE_EVT:
+			if (ESP_A2D_INIT_SUCCESS == a2d->a2d_prof_stat.init_state) {
+				ESP_LOGI(A2DP_TAG,"A2DP PROF STATE: Init Compl\n");
+			} else {
+				ESP_LOGI(A2DP_TAG,"A2DP PROF STATE: Deinit Compl\n");
+			}
+			break;
+
+		default:
+			ESP_LOGE(A2DP_TAG, "%s unhandled evt %d", __func__, event);
+			break;
+	}
+}
+
+/**
+ * @brief Utility structure that can be used to split a int32_t up into 2 separate channels with int16_t data.
+ * @author Phil Schatzmann
+ * @copyright Apache License Version 2
+ */
+struct __attribute__((packed)) Frame {
+  int16_t channel1;
+  int16_t channel2;
+
+  Frame(int v=0){
+    channel1 = channel2 = v;
+  }
+
+  Frame(int ch1, int ch2){
+    channel1 = ch1;
+    channel2 = ch2;
+  }
+
+};
+
+static void audio_data_callback(const uint8_t* data, uint32_t len) {
+	Frame* frame = (Frame*)data;
+	for (int i = 0; i < len/4; i++) {
+		int16_t temp = frame[i].channel1;
+		frame[i].channel1 = frame[i].channel2;
+		frame[i].channel2 = temp;
+	}
+
+	size_t bytes_written;
+	if (i2s_write(I2S_PORT, data, len, &bytes_written, portMAX_DELAY) != ESP_OK) {
+		ESP_LOGE(A2DP_TAG, "i2s_write has failed");
+	}
+
+	if (bytes_written < len) {
+		ESP_LOGE(A2DP_TAG, "Timeout: not all bytes were written to I2S");
+	}
+}
+
+void a2dp::init() {
+	ESP_LOGI(A2DP_TAG, "Initializing A2DP");
+
+	// Initialize A2DP sink
+	if (esp_a2d_register_callback(a2d_callback) != ESP_OK){
+		ESP_LOGE(A2DP_TAG,"esp_a2d_register_callback failed");
+	}
+	if (esp_a2d_sink_register_data_callback(audio_data_callback) != ESP_OK){
+		ESP_LOGE(A2DP_TAG,"esp_a2d_sink_register_data_callback failed");
+	}
+	if (esp_a2d_sink_init() != ESP_OK){
+		ESP_LOGE(A2DP_TAG,"esp_a2d_sink_init failed");
+	}
+}
+
+void a2dp::connect_to_last() {
+	if (nvs::has_last_connection()) {
+		esp_bd_addr_t last_connection = {0,0,0,0,0,0};
+		nvs::get_last_connection(last_connection);
+		if (esp_a2d_sink_connect(last_connection) == ESP_FAIL) {
+			ESP_LOGE(A2DP_TAG, "Failed connecting to device!");
+		}
+	} else {
+		bluetooth::set_scan_mode(true);
+	}
+}
+

software/main/src/avrcp.cpp

@@ -0,0 +1,56 @@
+#include "esp_log.h"
+#include "esp_avrc_api.h"
+
+#include "avrcp.h"
+#include "helper.h"
+
+#define AVRCP_TAG "APP_AVRCP"
+
+static void rc_tg_callback(esp_avrc_tg_cb_event_t event, esp_avrc_tg_cb_param_t* param) {
+	ESP_LOGD(AVRCP_TAG, "%s evt %d", __func__, event);
+
+	switch (event) {
+		case ESP_AVRC_TG_SET_ABSOLUTE_VOLUME_CMD_EVT:
+			ESP_LOGI(AVRCP_TAG, "AVRC set absolute volume: %d%%", (int)param->set_abs_vol.volume * 100/ 0x7f);
+			// The phone want to change the volume
+			break;
+
+		case ESP_AVRC_TG_REGISTER_NOTIFICATION_EVT:
+			ESP_LOGI(AVRCP_TAG, "AVRC register event notification: %d, param: 0x%x", param->reg_ntf.event_id, param->reg_ntf.event_parameter);
+			if (param->reg_ntf.event_id == ESP_AVRC_RN_VOLUME_CHANGE) {
+				ESP_LOGI(AVRCP_TAG, "AVRC Volume Changes Supported");
+
+				// Notify the phone of the current volume
+				// @TODO This does not appear to set the volume correctly on my OnePlus 7T Pro
+				// However for now it is not really relevant as the volume control is doen by the car
+				// In the future however it might be nice to sync the value on the phone, the esp and the car
+				// This will require some sort of CAN bus access
+				esp_avrc_rn_param_t rn_param;
+				rn_param.volume = 127;
+				esp_avrc_tg_send_rn_rsp(ESP_AVRC_RN_VOLUME_CHANGE, ESP_AVRC_RN_RSP_INTERIM, &rn_param);
+			} else {
+				ESP_LOGW(AVRCP_TAG, "AVRC Volume Changes NOT Supported");
+			}
+			break;
+
+		default:
+			ESP_LOGE(AVRCP_TAG, "%s unhandled evt %d", __func__, event);
+			break;
+	}
+}
+
+void avrcp::init() {
+	ESP_LOGI(AVRCP_TAG, "Initializing AVRCP");
+
+	// Initialize AVRCP target
+	if (esp_avrc_tg_init() == ESP_OK) {
+		esp_avrc_tg_register_callback(rc_tg_callback);
+		esp_avrc_rn_evt_cap_mask_t evt_set = {0};
+		esp_avrc_rn_evt_bit_mask_operation(ESP_AVRC_BIT_MASK_OP_SET, &evt_set, ESP_AVRC_RN_VOLUME_CHANGE);
+		if (esp_avrc_tg_set_rn_evt_cap(&evt_set) != ESP_OK) {
+			ESP_LOGE(AVRCP_TAG, "esp_avrc_tg_set_rn_evt_cap failed");
+		}
+	} else {
+		ESP_LOGE(AVRCP_TAG, "esp_avrc_tg_init failed");
+	}
+}

software/main/src/bluetooth.cpp

@@ -0,0 +1,155 @@
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+#include "esp_log.h"
+#include "esp_bt.h"
+#include "esp_bt_main.h"
+#include "esp_bt_device.h"
+#include "esp_gap_bt_api.h"
+#include "esp_spp_api.h"
+
+#include "bluetooth.h"
+
+#include "helper.h"
+#include <cstring>
+
+#define BT_TAG "APP_BT"
+
+static bool start() {
+	ESP_LOGI(BT_TAG, "BT Start");
+	if (esp_bt_controller_get_status() == ESP_BT_CONTROLLER_STATUS_ENABLED) {
+		ESP_LOGI(BT_TAG, "Already enabled");
+		return true;
+	}
+
+	esp_bt_controller_config_t cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
+
+	if (esp_bt_controller_get_status() == ESP_BT_CONTROLLER_STATUS_IDLE) {
+		ESP_LOGI(BT_TAG, "Idle");
+		esp_bt_controller_init(&cfg);
+		while (esp_bt_controller_get_status() == ESP_BT_CONTROLLER_STATUS_IDLE) {}
+	}
+
+	if (esp_bt_controller_get_status() == ESP_BT_CONTROLLER_STATUS_INITED) {
+		if (esp_bt_controller_enable(ESP_BT_MODE_CLASSIC_BT)) {
+			ESP_LOGE(BT_TAG, "BT Enable failed");
+			return false;
+		}
+	}
+
+	if (esp_bt_controller_get_status() == ESP_BT_CONTROLLER_STATUS_ENABLED) {
+		ESP_LOGI(BT_TAG, "Enabled");
+		return true;
+	}
+
+	ESP_LOGE(BT_TAG, "BT Start failed");
+	return false;
+}
+
+static void app_gap_callback(esp_bt_gap_cb_event_t event, esp_bt_gap_cb_param_t *param) {
+	switch (event) {
+		case ESP_BT_GAP_AUTH_CMPL_EVT: {
+			if (param->auth_cmpl.stat == ESP_BT_STATUS_SUCCESS) {
+				ESP_LOGI(BT_TAG, "authentication success: %s", param->auth_cmpl.device_name);
+			} else {
+				ESP_LOGE(BT_TAG, "authentication failed, status:%d", param->auth_cmpl.stat);
+			}
+			break;
+		}
+
+		case ESP_BT_GAP_PIN_REQ_EVT: {
+			esp_bd_addr_t peer_bd_addr = {0,0,0,0,0,0};
+			memcpy(peer_bd_addr, param->pin_req.bda, ESP_BD_ADDR_LEN);
+			ESP_LOGI(BT_TAG, "partner address: %s", addr_to_str(peer_bd_addr));
+			break;
+		}
+
+		case ESP_BT_GAP_CFM_REQ_EVT: {
+			esp_bd_addr_t peer_bd_addr = {0,0,0,0,0,0};
+			memcpy(peer_bd_addr, param->cfm_req.bda, ESP_BD_ADDR_LEN);
+			ESP_LOGI(BT_TAG, "partner address: %s", addr_to_str(peer_bd_addr));
+
+			ESP_LOGI(BT_TAG, "ESP_BT_GAP_CFM_REQ_EVT Please confirm the passkey: %d", param->cfm_req.num_val);
+			break;
+		}
+
+		case ESP_BT_GAP_KEY_NOTIF_EVT: {
+			ESP_LOGI(BT_TAG, "ESP_BT_GAP_KEY_NOTIF_EVT passkey:%d", param->key_notif.passkey);
+			break;
+		}
+
+		case ESP_BT_GAP_KEY_REQ_EVT: {
+			ESP_LOGI(BT_TAG, "ESP_BT_GAP_KEY_REQ_EVT Please enter passkey!");
+			break;
+		 }
+
+		case ESP_BT_GAP_READ_REMOTE_NAME_EVT: {
+			ESP_LOGI(BT_TAG, "ESP_BT_GAP_READ_REMOTE_NAME_EVT stat:%d", param->read_rmt_name.stat);
+			if (param->read_rmt_name.stat == ESP_BT_STATUS_SUCCESS ) {
+				ESP_LOGI(BT_TAG, "ESP_BT_GAP_READ_REMOTE_NAME_EVT remote name:%s", param->read_rmt_name.rmt_name);
+				char remote_name[ESP_BT_GAP_MAX_BDNAME_LEN + 1];
+				memcpy(remote_name, param->read_rmt_name.rmt_name, ESP_BT_GAP_MAX_BDNAME_LEN );
+			}
+			break;
+		}
+
+		default: {
+			ESP_LOGI(BT_TAG, "%s invalid event: %d", __func__, event);
+			break;
+		}
+	}
+	return;
+}
+
+void bluetooth::init() {
+	ESP_LOGI(BT_TAG, "Initializing bluetooth");
+
+	if (!start()) {
+		ESP_LOGE(BT_TAG, "Failed to initialize controller");
+		return;
+	}
+
+	ESP_LOGI(BT_TAG, "Controller initialized");
+
+	esp_bluedroid_status_t bt_stack_status = esp_bluedroid_get_status();
+	if (bt_stack_status == ESP_BLUEDROID_STATUS_UNINITIALIZED) {
+		if (esp_bluedroid_init() != ESP_OK) {
+			ESP_LOGE(BT_TAG, "Failed to initialize bluedroid");
+			return;
+		}
+		ESP_LOGI(BT_TAG, "Bluedroid initialized");
+	}
+
+	while (bt_stack_status != ESP_BLUEDROID_STATUS_ENABLED) {
+		if (esp_bluedroid_enable() != ESP_OK) {
+			ESP_LOGE(BT_TAG, "Failed to enable bluedroid");
+			vTaskDelay(100 / portTICK_PERIOD_MS);
+		} else {
+			ESP_LOGI(BT_TAG, "Bluedroid enabled");
+		}
+		bt_stack_status = esp_bluedroid_get_status();
+	}
+
+	if (esp_bt_gap_register_callback(app_gap_callback) != ESP_OK) {
+		ESP_LOGE(BT_TAG,"gap register failed");
+		return;
+	}
+
+	esp_bt_dev_set_device_name("207 Music");
+
+	esp_bt_pin_code_t pin_code;
+	pin_code[0] = '6';
+	pin_code[1] = '9';
+	pin_code[2] = '4';
+	pin_code[3] = '2';
+	pin_code[4] = '0';
+	esp_bt_gap_set_pin(ESP_BT_PIN_TYPE_FIXED, 5, pin_code);
+}
+
+void bluetooth::set_scan_mode(bool connectable) {
+	if (esp_bt_gap_set_scan_mode(connectable ? ESP_BT_CONNECTABLE : ESP_BT_NON_CONNECTABLE, connectable ? ESP_BT_GENERAL_DISCOVERABLE : ESP_BT_NON_DISCOVERABLE)) {
+		ESP_LOGE(BT_TAG,"esp_bt_gap_set_scan_mode failed");
+	}
+}
+
+

software/main/src/helper.cpp

@@ -0,0 +1,14 @@
+#include "esp_log.h"
+
+#include "helper.h"
+
+const char* addr_to_str(esp_bd_addr_t bda) {
+    static char bda_str[18];
+    sprintf(bda_str, "%02x:%02x:%02x:%02x:%02x:%02x", bda[0], bda[1], bda[2], bda[3], bda[4], bda[5]);
+    return (const char*)bda_str;
+}
+
+const char* connection_state_to_str(esp_a2d_connection_state_t state) {
+	const char* states[4] = {"Disconnected", "Connecting", "Connected", "Disconnecting"};
+	return states[state];
+}

software/main/src/i2s.cpp

@@ -0,0 +1,56 @@
+#include "esp_log.h"
+#include "driver/i2s.h"
+
+#include "i2s.h"
+
+#define I2S_TAG "APP_I2S"
+
+void i2s::init() {
+	ESP_LOGI(I2S_TAG, "Initializing i2s");
+
+	i2s_port_t i2s_port = I2S_PORT;
+
+	i2s_config_t i2s_config = {
+		.mode = (i2s_mode_t) (I2S_MODE_MASTER | I2S_MODE_TX),
+		.sample_rate = get_sample_rate(),
+		.bits_per_sample = (i2s_bits_per_sample_t)16,
+		.channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,
+		.communication_format = (i2s_comm_format_t) (I2S_COMM_FORMAT_STAND_I2S),
+		.intr_alloc_flags = 0, // default interrupt priority
+		.dma_desc_num = 8,
+		.dma_frame_num = 64,
+		.use_apll = false,
+		.tx_desc_auto_clear = true // avoiding noise in case of data unavailability
+	};
+
+	if (i2s_driver_install(i2s_port, &i2s_config, 0, nullptr) != ESP_OK) {
+		ESP_LOGE(I2S_TAG, "i2s_driver_install failed");
+	}
+
+	i2s_pin_config_t pin_config = {
+		.bck_io_num = 26,
+		.ws_io_num = 25,
+		.data_out_num = 33,
+		.data_in_num = I2S_PIN_NO_CHANGE
+	};
+
+	if (i2s_set_pin(i2s_port, &pin_config) != ESP_OK) {
+		ESP_LOGE(I2S_TAG, "i2s_set_pin failed");
+	}
+
+}
+
+static uint32_t sample_rate = 44100;
+void i2s::set_sample_rate(uint32_t sp) {
+	sample_rate = sp;
+
+	if (i2s_set_clk(I2S_PORT, sample_rate, 16, I2S_CHANNEL_STEREO) != ESP_OK){
+		ESP_LOGE(I2S_TAG, "i2s_set_clk failed with samplerate=%d", sample_rate);
+	} else {
+		ESP_LOGI(I2S_TAG, "samplerate=%d", sample_rate);
+	}
+}
+
+uint32_t i2s::get_sample_rate() {
+	return sample_rate;
+}

software/main/src/main.cpp

@@ -0,0 +1,29 @@
+#include "esp_log.h"
+
+#include "esp_system.h"
+
+#include "storage.h"
+#include "i2s.h"
+#include "bluetooth.h"
+#include "avrcp.h"
+#include "a2dp.h"
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+#define APP_TAG "APP"
+
+extern "C" void app_main() {
+	ESP_LOGI(APP_TAG, "Starting Car Stereo");
+	ESP_LOGI(APP_TAG, "Available Heap: %u", esp_get_free_heap_size());
+
+	nvs::init();
+	i2s::init();
+	bluetooth::init();
+
+	avrcp::init();
+	a2dp::init();
+
+	a2dp::connect_to_last();
+}
+

software/main/src/storage.cpp

@@ -0,0 +1,81 @@
+#include <cstring>
+
+#include "esp_log.h"
+#include "nvs_flash.h"
+
+#include "storage.h"
+
+#define NVS_TAG "APP_NVS"
+
+void nvs::init() {
+    ESP_LOGI(NVS_TAG, "Initializing nvs");
+
+    esp_err_t err = nvs_flash_init();
+    if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND){
+        ESP_ERROR_CHECK(nvs_flash_erase());
+        err = nvs_flash_init();
+    }
+    ESP_ERROR_CHECK(err);
+}
+
+void nvs::get_last_connection(esp_bd_addr_t last_connection) {
+	nvs_handle handle;
+	esp_err_t err = nvs_open("connected_dba", NVS_READWRITE, &handle);
+	if (err != ESP_OK) {
+		ESP_LOGE(NVS_TAG, "NVS OPEN ERRRO");
+	}
+
+	esp_bd_addr_t bda;
+	size_t size = sizeof(bda);
+	err = nvs_get_blob(handle, "last_bda", bda, &size);
+	if (err != ESP_OK) {
+		if (err == ESP_ERR_NVS_NOT_FOUND) {
+			ESP_LOGI(NVS_TAG, "nvs_blob does not exists");
+		} else {
+			ESP_LOGE(NVS_TAG, "get_nvs_blob failed");
+		}
+	}
+
+	nvs_close(handle);
+	if (err == ESP_OK) {
+		memcpy(last_connection, bda, size);
+	}
+}
+
+void nvs::set_last_connection(esp_bd_addr_t bda) {
+	esp_bd_addr_t last_connection = {0,0,0,0,0,0};
+	get_last_connection(last_connection);
+
+	if (memcmp(bda, last_connection, ESP_BD_ADDR_LEN) == 0) {
+		// Nothing has changed
+		return;
+	}
+
+	nvs_handle handle;
+	esp_err_t err = nvs_open("connected_dba", NVS_READWRITE, &handle);
+	if (err != ESP_OK) {
+		ESP_LOGE(NVS_TAG, "NVS OPEN ERRRO");
+	}
+
+	err = nvs_set_blob(handle, "last_bda", bda, ESP_BD_ADDR_LEN);
+	if (err == ESP_OK) {
+		err = nvs_commit(handle);
+	} else {
+		ESP_LOGE(NVS_TAG, "NVS_WRITE_ERROR");
+	}
+
+	if (err != ESP_OK) {
+		ESP_LOGE(NVS_TAG, "NVS COMMIT ERROR");
+	}
+
+	nvs_close(handle);
+}
+
+bool nvs::has_last_connection() {
+	esp_bd_addr_t empty = {0,0,0,0,0,0};
+	esp_bd_addr_t last_connection = {0,0,0,0,0,0};
+	get_last_connection(last_connection);
+
+	int result = memcmp(last_connection, empty, ESP_BD_ADDR_LEN);
+	return result != 0;
+}

software/main/src/wav.cpp

@@ -0,0 +1,65 @@
+#include "esp_log.h"
+#include "driver/i2s.h"
+
+#include "wav.h"
+#include "i2s.h"
+
+#define WAV_TAG "APP_WAV"
+#define WAV_HEADER_SIZE 44
+#define I2S_BUFFER_SIZE 512
+
+struct PlayWavParam {
+	const uint8_t* data;
+	uint32_t len;
+};
+
+static void task(void* param) {
+	ESP_LOGI(WAV_TAG, "Playing sample...");
+	PlayWavParam* p = (PlayWavParam*)param;
+
+	// Switch to mono since the samples are all in mono to save space
+	i2s_zero_dma_buffer(I2S_PORT);
+	i2s_set_clk(I2S_PORT, 44100, 16, I2S_CHANNEL_MONO);
+
+	for (uint32_t index = 0; index < p->len; index += I2S_BUFFER_SIZE) {
+		int rest = p->len - index;
+
+		size_t byte_size = I2S_BUFFER_SIZE;
+		if (rest < I2S_BUFFER_SIZE) {
+			byte_size = rest;
+		}
+
+		const unsigned char* current = p->data + WAV_HEADER_SIZE + index;
+		size_t bytes_written;
+		if (i2s_write(I2S_PORT, current, byte_size, &bytes_written, portMAX_DELAY) != ESP_OK) {
+			ESP_LOGE(WAV_TAG, "i2s_write has failed");
+		}
+
+		if (bytes_written < byte_size) {
+			ESP_LOGE(WAV_TAG, "Timeout: not all bytes were written to I2S");
+		}
+	}
+
+	// Switch back to stereo with the correct samplerate
+	i2s_zero_dma_buffer(I2S_PORT);
+	i2s_set_clk(I2S_PORT, i2s::get_sample_rate(), 16, I2S_CHANNEL_STEREO);
+
+	ESP_LOGI(WAV_TAG, "Done");
+
+	free(p);
+	vTaskDelete(nullptr);
+}
+
+void wav::play(const uint8_t* start, const uint8_t* end) {
+	ESP_LOGI(WAV_TAG, "Creating Play Wav Task");
+	uint32_t len = (end - start - WAV_HEADER_SIZE);
+
+	PlayWavParam* param = new PlayWavParam;
+	param->data = start;
+	param->len = len;
+
+	if (xTaskCreate(task, "PlayWav", 2048, param, configMAX_PRIORITIES - 3, nullptr) != pdPASS) {
+		ESP_LOGE(WAV_TAG, "Failed to create play wav task");
+	}
+}
+

software/source.sh

@@ -0,0 +1 @@
+export IDF_TOOLS_PATH=$(dirname $(readlink -f $0))/tools