Wokwi - Online ESP32, STM32, Arduino Simulator

#include <WiFi.h>
#include <ESPAsyncWebServer.h>
#include <AsyncTCP.h>
#include <nvs_flash.h>
#include <nvs.h>

// Wi-Fi Credentials
const char* ssid = "ESP32_Hotspot";
const char* password = "your_password";

// Audio Configuration Structure
#define NUM_EQ_BANDS 7

typedef struct {
    int32_t i2s_num_high;
    int32_t i2s_num_mid;
    int32_t i2s_num_sub;
    float crossover_high;
    float crossover_mid;
    float crossover_sub;
    int32_t routing_high;
    int32_t routing_mid;
    int32_t routing_sub;
    float eq_gain[NUM_EQ_BANDS];  // Gain for each EQ band
} AudioChannelConfig;

AudioChannelConfig audio_config;
AsyncWebServer server(80);

// Workaround to store floats in NVS by converting them to strings
void nvs_set_float(nvs_handle_t nvs_handle, const char* key, float value) {
    char str_value[32];
    snprintf(str_value, sizeof(str_value), "%f", value);
    nvs_set_str(nvs_handle, key, str_value);
}

float nvs_get_float(nvs_handle_t nvs_handle, const char* key, float default_value) {
    size_t required_size;
    nvs_get_str(nvs_handle, key, NULL, &required_size);
    char* str_value = (char*)malloc(required_size);
    nvs_get_str(nvs_handle, key, str_value, &required_size);
    float value = atof(str_value);
    free(str_value);
    return value == 0 ? default_value : value;
}

void init_nvs() {
    nvs_flash_init();
}

// Read configuration from NVS
void read_config_from_nvs() {
    nvs_handle_t nvs_handle;
    nvs_open("storage", NVS_READWRITE, &nvs_handle);

    nvs_get_i32(nvs_handle, "i2s_num_high", &audio_config.i2s_num_high);
    nvs_get_i32(nvs_handle, "i2s_num_mid", &audio_config.i2s_num_mid);
    nvs_get_i32(nvs_handle, "i2s_num_sub", &audio_config.i2s_num_sub);

    audio_config.crossover_high = nvs_get_float(nvs_handle, "crossover_high", 1000.0);
    audio_config.crossover_mid = nvs_get_float(nvs_handle, "crossover_mid", 500.0);
    audio_config.crossover_sub = nvs_get_float(nvs_handle, "crossover_sub", 200.0);

    nvs_get_i32(nvs_handle, "routing_high", &audio_config.routing_high);
    nvs_get_i32(nvs_handle, "routing_mid", &audio_config.routing_mid);
    nvs_get_i32(nvs_handle, "routing_sub", &audio_config.routing_sub);

    for (int i = 0; i < NUM_EQ_BANDS; i++) {
        String param_name = "eq_gain" + String(i);
        audio_config.eq_gain[i] = nvs_get_float(nvs_handle, param_name.c_str(), 0.0);
    }

    nvs_close(nvs_handle);
}

// Save configuration to NVS
void save_config_to_nvs() {
    nvs_handle_t nvs_handle;
    nvs_open("storage", NVS_READWRITE, &nvs_handle);

    nvs_set_i32(nvs_handle, "i2s_num_high", audio_config.i2s_num_high);
    nvs_set_i32(nvs_handle, "i2s_num_mid", audio_config.i2s_num_mid);
    nvs_set_i32(nvs_handle, "i2s_num_sub", audio_config.i2s_num_sub);

    nvs_set_float(nvs_handle, "crossover_high", audio_config.crossover_high);
    nvs_set_float(nvs_handle, "crossover_mid", audio_config.crossover_mid);
    nvs_set_float(nvs_handle, "crossover_sub", audio_config.crossover_sub);

    nvs_set_i32(nvs_handle, "routing_high", audio_config.routing_high);
    nvs_set_i32(nvs_handle, "routing_mid", audio_config.routing_mid);
    nvs_set_i32(nvs_handle, "routing_sub", audio_config.routing_sub);

    for (int i = 0; i < NUM_EQ_BANDS; i++) {
        String param_name = "eq_gain" + String(i);
        nvs_set_float(nvs_handle, param_name.c_str(), audio_config.eq_gain[i]);
    }

    nvs_commit(nvs_handle);
    nvs_close(nvs_handle);
}

// Web server to serve the configuration page
void init_web_server() {
    server.on("/config", HTTP_GET, [](AsyncWebServerRequest *request) {
        String response = "<html><body><h2>7-Band Graphic EQ</h2><form action='/update' method='POST'>";
        
        // EQ Sliders
        const char* eq_labels[NUM_EQ_BANDS] = {"60Hz", "170Hz", "310Hz", "600Hz", "1kHz", "3kHz", "6kHz"};
        for (int i = 0; i < NUM_EQ_BANDS; i++) {
            response += "<label for='eq_band" + String(i) + "'>" + String(eq_labels[i]) + ": </label>";
            response += "<input type='range' id='eq_band" + String(i) + "' name='eq_gain" + String(i) + "' min='-12' max='12' step='0.1' value='" + String(audio_config.eq_gain[i]) + "' oninput='document.getElementById(\"val" + String(i) + "\").innerText = this.value'>";
            response += "<span id='val" + String(i) + "'>" + String(audio_config.eq_gain[i]) + "</span>dB<br>";
        }

        // Other settings (crossover, routing) can be added here similarly...

        response += "<br><input type='submit' value='Update'></form></body></html>";
        request->send(200, "text/html", response);
    });

    server.on("/update", HTTP_POST, [](AsyncWebServerRequest *request) {
        // Update EQ settings
        for (int i = 0; i < NUM_EQ_BANDS; i++) {
            String param_name = "eq_gain" + String(i);
            if (request->hasParam(param_name, true)) {
                audio_config.eq_gain[i] = request->getParam(param_name, true)->value().toFloat();
            }
        }

        // Update other settings (crossover, routing)...

        // Save updated configuration to NVS
        save_config_to_nvs();

        request->send(200, "text/html", "Configuration updated! <a href='/config'>Go back</a>");
    });

    server.begin();
}

// Main setup function
void setup() {
    Serial.begin(115200);
    init_nvs();
    read_config_from_nvs();

    // Set up the ESP32 as an Access Point
    WiFi.softAP(ssid, password);

    IPAddress IP = WiFi.softAPIP();
    Serial.print("AP IP address: ");
    Serial.println(IP);

    init_web_server();
}

// Main loop function
void loop() {
    // Process audio with EQ, crossover, and routing...
}