Basic SD working

src/core/diagnostics_state.cpp

@@ -11,13 +11,7 @@ void DiagnosticsState::update()
         ESP.getMinFreeHeap();
 
     current.cpuFrequency =
-        ESP.getCpuFreqMHz();
-
-    Serial.print("#update: ");
-    Serial.println(current.freeHeap);
-    Serial.println("Calling current from update");
-    getCurrent();
-    
+        ESP.getCpuFreqMHz();    
 }
 
 
@@ -29,9 +23,5 @@ DiagnosticSample DiagnosticsState::getCurrent()
     sample.freeHeap = current.freeHeap;
     sample.minimumFreeHeap = current.minimumFreeHeap;
     sample.cpuFrequency = current.cpuFrequency;
-
-    Serial.print("#getCurrent: ");
-    Serial.println(sample.freeHeap);
-    Serial.println(sample.timestamp);
     return sample;
 }

src/main.cpp

@@ -11,8 +11,11 @@
 #include "services/ota_service.h"
 #include "services/web_service.h"
 
+#include "storage/sd_manager.h"
+
 #include "tasks/system_task.h"
 #include "tasks/diagnostics_task.h"
+#include "tasks/storage_task.h"
 
 
 DashboardState dashboardState;
@@ -31,6 +34,9 @@ SystemTask systemTask(services);
 
 DiagnosticsTask diagnosticsTask(diagnosticsState);
 
+SDManager sdManager;
+StorageTask storageTask(sdManager);
+
 void setup()
 {
     Serial.begin(115200);
@@ -42,6 +48,7 @@ void setup()
 
     systemTask.start();
     diagnosticsTask.start();
+    storageTask.start();
 }
 
 

src/services/web_service.cpp

@@ -128,7 +128,6 @@ Firmware Version: <div id="firmware_version">Loading...</div>
 void WebService::broadcastState()
 {
     DiagnosticSample diagnostics = diagnosticsState.getCurrent();
-    Serial.println(diagnostics.freeHeap);
     String json = "{";
 
     // Opening system tag:

src/storage/sd_manager.cpp

@@ -0,0 +1,334 @@
+#include "sd_manager.h"
+
+#include "storage_config.h"
+
+#include <driver/gpio.h>
+
+// Both backends are compiled into the image so that the SDIO path is
+// compile-checked even while the system still runs SPI for bring-up.
+#include <SD.h>
+#include <SD_MMC.h>
+
+namespace
+{
+
+class SpiBackend : public StorageBackend
+{
+public:
+    bool begin() override
+    {
+        // Explicit SPI instance so the pin wiring is driven from
+        // storage_config.h rather than the board defaults. The second
+        // spi.begin() call made inside SDFS::begin() is a no-op because the
+        // bus is already started with these pins.
+        static SPIClass spi;
+
+        spi.begin(
+            STORAGE_SPI_SCK,
+            STORAGE_SPI_MISO,
+            STORAGE_SPI_MOSI,
+            STORAGE_SPI_CS
+        );
+
+        // Cheap breakout modules often omit the pull-up resistors the SD
+        // spec expects on the idle-high lines. The ESP32 SPI HAL clears the
+        // internal pull-ups when it attaches a pin (esp32-hal-spi.c), so a
+        // floating MISO/CS means the card never answers CMD0 during init
+        // ("Card Failed! cmd: 0x00"). Re-enable the pull-ups directly so we
+        // do not disturb the pin's peripheral function.
+        gpio_pullup_en((gpio_num_t)STORAGE_SPI_MISO);
+        gpio_pullup_en((gpio_num_t)STORAGE_SPI_CS);
+
+        // Give the card a moment to stabilize after power-on before the init
+        // handshake starts (the framework sends 74+ dummy clocks, but some
+        // cards need a little more settling time on a fresh mount attempt).
+        delay(20);
+
+        return SD.begin(
+            STORAGE_SPI_CS,
+            spi,
+            STORAGE_SPI_FREQ,
+            STORAGE_MOUNT_POINT,
+            STORAGE_MAX_OPEN_FILES,
+            false // format_if_empty: never auto-format
+        );
+    }
+
+    void end() override
+    {
+        SD.end();
+    }
+
+    fs::FS& fs() override
+    {
+        return SD;
+    }
+
+    StorageCardType cardType() override
+    {
+        return mapType(SD.cardType());
+    }
+
+    uint64_t totalBytes() override
+    {
+        return SD.totalBytes();
+    }
+
+    uint64_t usedBytes() override
+    {
+        return SD.usedBytes();
+    }
+
+private:
+    static StorageCardType mapType(sdcard_type_t type)
+    {
+        switch (type)
+        {
+        case CARD_MMC:  return StorageCardType::MMC;
+        case CARD_SD:   return StorageCardType::SD;
+        case CARD_SDHC: return StorageCardType::SDHC;
+        case CARD_NONE: return StorageCardType::None;
+        default:        return StorageCardType::Unknown;
+        }
+    }
+};
+
+class SdmmcBackend : public StorageBackend
+{
+public:
+    bool begin() override
+    {
+        // The plain esp32dev variant does not pre-wire the SDMMC pins, so
+        // they must always be set explicitly. The classic ESP32 routes the
+        // SDMMC peripheral through the GPIO matrix, so the pins defined in
+        // storage_config.h are fully re-routable.
+        if (!SD_MMC.setPins(
+                STORAGE_SDMMC_CLK,
+                STORAGE_SDMMC_CMD,
+                STORAGE_SDMMC_D0,
+                STORAGE_SDMMC_D1,
+                STORAGE_SDMMC_D2,
+                STORAGE_SDMMC_D3))
+        {
+            return false;
+        }
+
+        return SD_MMC.begin(
+            STORAGE_MOUNT_POINT,
+            STORAGE_SDMMC_MODE_1BIT,          // false == 4-bit bus
+            STORAGE_SDMMC_FORMAT_IF_FAILED,   // never auto-format
+            STORAGE_SDMMC_FREQ_HZ,            // 40 MHz == SDMMC_FREQ_HIGHSPEED
+            STORAGE_MAX_OPEN_FILES
+        );
+    }
+
+    void end() override
+    {
+        SD_MMC.end();
+    }
+
+    fs::FS& fs() override
+    {
+        return SD_MMC;
+    }
+
+    StorageCardType cardType() override
+    {
+        return mapType(SD_MMC.cardType());
+    }
+
+    uint64_t totalBytes() override
+    {
+        return SD_MMC.totalBytes();
+    }
+
+    uint64_t usedBytes() override
+    {
+        return SD_MMC.usedBytes();
+    }
+
+private:
+    static StorageCardType mapType(sdcard_type_t type)
+    {
+        switch (type)
+        {
+        case CARD_MMC:  return StorageCardType::MMC;
+        case CARD_SD:   return StorageCardType::SD;
+        case CARD_SDHC: return StorageCardType::SDHC;
+        case CARD_NONE: return StorageCardType::None;
+        default:        return StorageCardType::Unknown;
+        }
+    }
+};
+
+} // namespace
+
+
+SDManager::SDManager()
+:
+backend(nullptr),
+mounted(false)
+{
+}
+
+
+bool SDManager::begin()
+{
+    if (mounted)
+    {
+        return true;
+    }
+
+#if STORAGE_IFACE == STORAGE_IFACE_SDMMC
+    backend = new SdmmcBackend();
+#else
+    backend = new SpiBackend();
+#endif
+
+    if (backend == nullptr)
+    {
+        return false;
+    }
+
+    mounted = backend->begin();
+
+    if (!mounted)
+    {
+        Serial.println("[Storage] SD card mount FAILED");
+        delete backend;
+        backend = nullptr;
+    }
+
+    return mounted;
+}
+
+
+void SDManager::end()
+{
+    if (backend != nullptr)
+    {
+        backend->end();
+        delete backend;
+        backend = nullptr;
+    }
+
+    mounted = false;
+}
+
+
+bool SDManager::isMounted() const
+{
+    return mounted;
+}
+
+
+fs::FS& SDManager::fs()
+{
+    return backend->fs();
+}
+
+
+const char* SDManager::cardTypeName(StorageCardType type)
+{
+    switch (type)
+    {
+    case StorageCardType::MMC:     return "MMC";
+    case StorageCardType::SD:      return "SD";
+    case StorageCardType::SDHC:    return "SDHC";
+    case StorageCardType::Unknown: return "Unknown";
+    case StorageCardType::None:
+    default:                       return "None";
+    }
+}
+
+
+void SDManager::printCardInfo()
+{
+    if (!mounted)
+    {
+        Serial.println("[Storage] Card info unavailable (not mounted)");
+        return;
+    }
+
+    uint64_t total = backend->totalBytes();
+    uint64_t used  = backend->usedBytes();
+    uint64_t free  = (total > used) ? (total - used) : 0;
+
+    Serial.println("----------------------------------------");
+    Serial.println("SD card information");
+    Serial.println("----------------------------------------");
+    Serial.printf("  Type   : %s\n", cardTypeName(backend->cardType()));
+    Serial.printf("  Total  : %llu bytes\n", (unsigned long long)total);
+    Serial.printf("  Used   : %llu bytes\n", (unsigned long long)used);
+    Serial.printf("  Free   : %llu bytes\n", (unsigned long long)free);
+    Serial.println("----------------------------------------");
+}
+
+
+void SDManager::listFiles()
+{
+    if (!mounted)
+    {
+        Serial.println("[Storage] Cannot list files (not mounted)");
+        return;
+    }
+
+    Serial.println("Files on SD card:");
+    Serial.println("----------------------------------------");
+
+    char path[256];
+    snprintf(path, sizeof(path), "/");
+
+    listFilesRecursive(backend->fs(), path, sizeof(path), 0);
+
+    Serial.println("----------------------------------------");
+    Serial.println("End of listing");
+}
+
+
+void SDManager::listFilesRecursive(fs::FS& files, char* path, size_t pathSize, uint8_t depth)
+{
+    if (depth > STORAGE_LIST_MAX_DEPTH)
+    {
+        Serial.printf("  ... (max depth %u reached)\n", STORAGE_LIST_MAX_DEPTH);
+        return;
+    }
+
+    File dir = files.open(path);
+
+    if (!dir)
+    {
+        Serial.printf("  [error] cannot open: %s\n", path);
+        return;
+    }
+
+    if (!dir.isDirectory())
+    {
+        Serial.printf("  %s (%llu bytes)\n", path, (unsigned long long)dir.size());
+        dir.close();
+        return;
+    }
+
+    File entry;
+    while ((entry = dir.openNextFile()))
+    {
+        size_t base = strlen(path);
+
+        if (entry.isDirectory())
+        {
+            snprintf(path + base, pathSize - base, "/%s", entry.name());
+            Serial.printf("  %s/\n", path);
+            listFilesRecursive(files, path, pathSize, depth + 1);
+            path[base] = '\0';
+        }
+        else
+        {
+            snprintf(path + base, pathSize - base, "/%s", entry.name());
+            Serial.printf("  %s (%llu bytes)\n", path, (unsigned long long)entry.size());
+        }
+
+        entry.close();
+    }
+
+    dir.close();
+}

src/storage/sd_manager.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include <Arduino.h>
+#include <FS.h>
+
+// StorageCardType decouples the rest of the system from the SD/SD_MMC
+// library enum so nothing outside sd_manager.cpp needs to know which
+// hardware interface is in use.
+enum class StorageCardType
+{
+    None,
+    MMC,
+    SD,
+    SDHC,
+    Unknown
+};
+
+// Hardware abstraction for the SD card transport. The concrete backend
+// (SPI today, SDIO later) is selected at build time in storage_config.h.
+// Everything downstream (StorageTask, future DataLogger) talks only to
+// the `fs::FS` reference, so swapping SPI for SDIO touches no other code.
+class StorageBackend
+{
+public:
+    virtual ~StorageBackend() {}
+
+    virtual bool begin() = 0;
+    virtual void end() = 0;
+
+    virtual fs::FS& fs() = 0;
+
+    virtual StorageCardType cardType() = 0;
+    virtual uint64_t totalBytes() = 0;
+    virtual uint64_t usedBytes() = 0;
+};
+
+// Owns the selected backend, mounts the card, and provides the boot-time
+// info/listing report. The mount and any file access are blocking and are
+// expected to be driven from the dedicated StorageTask on core 0.
+class SDManager
+{
+public:
+    SDManager();
+
+    bool begin();
+    void end();
+
+    bool isMounted() const;
+
+    fs::FS& fs();
+
+    void printCardInfo();
+    void listFiles();
+
+private:
+    StorageBackend* backend;
+    bool mounted;
+
+    void listFilesRecursive(fs::FS& files, char* path, size_t pathSize, uint8_t depth);
+    static const char* cardTypeName(StorageCardType type);
+};

src/storage/storage_config.h

@@ -0,0 +1,99 @@
+#pragma once
+
+// ============================================================================
+//  Storage configuration
+// ============================================================================
+//
+//  This header is the single place to configure how the Hub talks to the
+//  SD card. Two hardware interfaces are supported by the Arduino-ESP32
+//  framework, and both are implemented behind the StorageBackend interface
+//  in sd_manager.cpp:
+//
+//    STORAGE_IFACE_SPI   - Uses the `SD` library (SPI protocol). This is the
+//                          bring-up path for the current breakout module,
+//                          which only breaks out the 4 SPI lines.
+//                          Max practical throughput: ~1-2 MB/s. NOT enough
+//                          for the 6-8 MB/s audio logging target.
+//
+//    STORAGE_IFACE_SDMMC - Uses the `SD_MMC` library (SDIO protocol, the
+//                          SDMMC peripheral). This is the production path.
+//                          4-bit mode @ 40 MHz (SDMMC_FREQ_HIGHSPEED) gives
+//                          roughly 8-12 MB/s, which comfortably meets the
+//                          target. REQUIRED for the final design.
+//
+//  TO MIGRATE TO SDIO (the new SDIO-capable board that is being shipped):
+//
+//    1. Change STORAGE_IFACE below from STORAGE_IFACE_SPI to
+//       STORAGE_IFACE_SDMMC.
+//
+//    2. Wire the SD card to the SDIO lines listed in the STORAGE_SDMMC_*
+//       defines below. On the classic ESP32 the SDMMC peripheral is routed
+//       through the GPIO matrix, so these pins can be changed to any free
+//       GPIO simply by editing the defines.
+//
+//    3. Keep STORAGE_SDMMC_MODE_1BIT as `false` (4-bit bus is required for
+//       the write throughput) and keep STORAGE_SDMMC_FORMAT_IF_FAILED as
+//       `false` (a foreign/unformatted card must never be auto-formatted).
+//
+//    4. Everything downstream (StorageTask, SDManager, and the future
+//       DataLogger) talks only through the `fs::FS` interface, so no other
+//       code changes are needed.
+// ============================================================================
+
+// --- Backend selection ------------------------------------------------------
+
+#define STORAGE_IFACE_SPI     1
+#define STORAGE_IFACE_SDMMC   2
+
+// SPI until the SDIO-capable board arrives.
+#ifndef STORAGE_IFACE
+#define STORAGE_IFACE STORAGE_IFACE_SPI
+#endif
+
+// --- Common -----------------------------------------------------------------
+
+// Single canonical mount point so file paths never change when the backend
+// is switched (the SD lib defaults to "/sd", SD_MMC to "/sdcard").
+#define STORAGE_MOUNT_POINT      "/sdcard"
+
+#define STORAGE_MAX_OPEN_FILES   5
+
+// --- SPI (bring-up only) ----------------------------------------------------
+
+// Default VSPI pins on the classic ESP32 DevKitC (variant/pins_arduino.h).
+#define STORAGE_SPI_CS     5
+#define STORAGE_SPI_SCK    18
+#define STORAGE_SPI_MOSI   23
+#define STORAGE_SPI_MISO   19
+
+// 10 MHz is a reliable default for breadboard/jumper-wire bring-up. The SD
+// init handshake always runs at 400 kHz regardless (see sd_diskio.cpp), so a
+// mount failure is NOT a frequency problem - check power, wiring, pull-ups
+// and card seating first. Raise to 20 MHz once the wiring is proven.
+#define STORAGE_SPI_FREQ   10000000UL
+
+// --- SDIO / SD_MMC (production, 4-bit) --------------------------------------
+
+// Default ESP32 SDMMC slot-1 pins (GPIO matrix, freely re-routable).
+#define STORAGE_SDMMC_CLK  6
+#define STORAGE_SDMMC_CMD  11
+#define STORAGE_SDMMC_D0   7
+#define STORAGE_SDMMC_D1   8
+#define STORAGE_SDMMC_D2   9
+#define STORAGE_SDMMC_D3   10
+
+// false = 4-bit wide bus (required for >8 MB/s). Do NOT enable 1-bit mode.
+#define STORAGE_SDMMC_MODE_1BIT          false
+
+// NEVER auto-format: an unformatted/foreign card must never be destroyed.
+#define STORAGE_SDMMC_FORMAT_IF_FAILED   false
+
+// 40 MHz == SDMMC_FREQ_HIGHSPEED. Written as a literal to keep this header
+// free of driver includes.
+#define STORAGE_SDMMC_FREQ_HZ            40000000
+
+// --- Boot-time file listing -------------------------------------------------
+
+// Maximum directory depth printed during the recursive boot listing. Guards
+// the StorageTask stack against pathological directory nesting.
+#define STORAGE_LIST_MAX_DEPTH   10

src/tasks/storage_task.cpp

@@ -0,0 +1,72 @@
+#include "storage_task.h"
+
+
+StorageTask::StorageTask(SDManager& manager)
+:
+storage(manager),
+taskHandle(nullptr)
+{
+}
+
+
+void StorageTask::start()
+{
+    // Dedicated task on core 0 so SD card work never blocks the services
+    // running on core 1 (SystemTask / DiagnosticsTask). The 8 KB stack is
+    // sized for the recursive boot-time file listing; the eventual
+    // producer/consumer logging loop will also live here.
+    xTaskCreatePinnedToCore(
+        taskEntry,
+        "StorageTask",
+        8192,
+        this,
+        3,
+        &taskHandle,
+        0
+    );
+}
+
+
+void StorageTask::taskEntry(void* parameter)
+{
+    StorageTask* task =
+        static_cast<StorageTask*>(parameter);
+
+    task->run();
+}
+
+
+void StorageTask::run()
+{
+    Serial.println("[Storage] Initializing SD card...");
+
+    // Retry the mount until it succeeds. This keeps the card dead-pin-capable:
+    // reseating the card, fixing a wire, or powering the module will bring it
+    // up without rebooting the Hub. (The SD init handshake runs at 400 kHz, so
+    // a failure here is wiring/power/seating/pull-up related, not speed.)
+    while (!storage.begin())
+    {
+        Serial.println("[Storage] SD card mount FAILED.");
+        Serial.println("[Storage] Check: 3.3V power + common ground, CS/SCK/MOSI/MISO wiring,");
+        Serial.println("[Storage]       card fully seated (click), and module pull-ups.");
+        Serial.println("[Storage] Retrying in 5 s...");
+        vTaskDelay(pdMS_TO_TICKS(5000));
+    }
+
+    storage.printCardInfo();
+    storage.listFiles();
+
+    TickType_t lastWake =
+        xTaskGetTickCount();
+
+    while (true)
+    {
+        // Future integration point: a producer/consumer queue will feed
+        // audio data here to be flushed to the card. For now the task
+        // simply idles while the system runs.
+        vTaskDelayUntil(
+            &lastWake,
+            pdMS_TO_TICKS(1000)
+        );
+    }
+}

src/tasks/storage_task.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <Arduino.h>
+
+#include "../storage/sd_manager.h"
+
+
+class StorageTask
+{
+public:
+    StorageTask(SDManager& manager);
+
+    void start();
+
+private:
+    static void taskEntry(void* parameter);
+    void run();
+
+    SDManager& storage;
+
+    TaskHandle_t taskHandle = nullptr;
+};