Add EEPROM EUI-48 device identity across firmware and API.

Read the factory 24AA025E48 serial after ADAU I2C boot, derive SoftAP SSID, BT name, STA hostname, and expose serialNumber on GET /api/health with graceful fallbacks.

Co-authored-by: Cursor <cursoragent@cursor.com>

Software/components/core/test/CMakeLists.txt

@@ -15,6 +15,8 @@ add_library(digiradio_core STATIC
     "${CORE_SRC_DIR}/FirmwareVersion.cpp"
     "${CORE_SRC_DIR}/HealthStatus.cpp"
     "${CORE_SRC_DIR}/HealthStatusJson.cpp"
+    "${CORE_SRC_DIR}/Eui48.cpp"
+    "${CORE_SRC_DIR}/DeviceIdentity.cpp"
     "${CORE_SRC_DIR}/Secret.cpp"
     "${CORE_SRC_DIR}/WifiSsid.cpp"
     "${CORE_SRC_DIR}/WifiCredentials.cpp"
@@ -49,6 +51,10 @@ target_include_directories(digiradio_core PUBLIC
     "${CMAKE_CURRENT_SOURCE_DIR}/../include"
 )
 
+add_executable(device_identity_test device_identity_test.cpp)
+target_link_libraries(device_identity_test PRIVATE digiradio_core)
+add_test(NAME device_identity_test COMMAND device_identity_test)
+
 add_executable(health_status_test health_status_test.cpp)
 target_link_libraries(health_status_test PRIVATE digiradio_core)
 add_test(NAME health_status_test COMMAND health_status_test)

Software/components/core/test/device_identity_test.cpp

@@ -0,0 +1,100 @@
+/**
+ * @file    device_identity_test.cpp
+ * @brief   Host tests for Eui48 and DeviceIdentity derivation.
+ *
+ * DigiRadio firmware — https://github.com/manvalan/DigiRadio
+ *
+ * Copyright 2026 Michele Bigi
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * @author  Michele Bigi
+ * @date    2026-07-07
+ */
+
+#include "core/DeviceIdentity.hpp"
+#include "core/Eui48.hpp"
+
+#include <array>
+#include <cstdlib>
+#include <iostream>
+#include <string>
+
+namespace {
+
+[[nodiscard]] bool expectEqual(std::string_view actual,
+                               std::string_view expected)
+{
+    if (actual == expected) {
+        return true;
+    }
+    std::cerr << "expected: " << expected << "\nactual:   " << actual << '\n';
+    return false;
+}
+
+[[nodiscard]] int runKnownEuiTest()
+{
+    const std::array<std::uint8_t, 6> bytes = {
+        0x00U, 0x04U, 0xA3U, 0x12U, 0x34U, 0x56U,
+    };
+    const core::Eui48 eui = core::Eui48::fromBytes(bytes);
+    if (!expectEqual(eui.serialNumber(), "0004A3123456")) {
+        return EXIT_FAILURE;
+    }
+    if (!expectEqual(eui.shortSuffix(), "123456")) {
+        return EXIT_FAILURE;
+    }
+
+    const core::DeviceIdentity identity = core::DeviceIdentity::fromEui48(eui);
+    if (!identity.isKnown()) {
+        std::cerr << "expected known identity\n";
+        return EXIT_FAILURE;
+    }
+    if (!expectEqual(identity.serialNumber(), "0004A3123456")) {
+        return EXIT_FAILURE;
+    }
+    if (!expectEqual(identity.softApSsid(), "DigiRadio-123456")) {
+        return EXIT_FAILURE;
+    }
+    if (!expectEqual(identity.bluetoothName(), "DigiRadio-123456")) {
+        return EXIT_FAILURE;
+    }
+    if (!expectEqual(identity.hostname(), "digiradio-123456")) {
+        return EXIT_FAILURE;
+    }
+    return EXIT_SUCCESS;
+}
+
+[[nodiscard]] int runUnknownIdentityTest()
+{
+    const core::DeviceIdentity identity = core::DeviceIdentity::unknown();
+    if (identity.isKnown()) {
+        std::cerr << "expected unknown identity\n";
+        return EXIT_FAILURE;
+    }
+    if (!expectEqual(identity.serialNumber(), "unknown")) {
+        return EXIT_FAILURE;
+    }
+    if (!expectEqual(identity.softApSsid(), "DigiRadio-setup")) {
+        return EXIT_FAILURE;
+    }
+    if (!expectEqual(identity.bluetoothName(), "DigiRadio")) {
+        return EXIT_FAILURE;
+    }
+    if (!expectEqual(identity.hostname(), "digiradio")) {
+        return EXIT_FAILURE;
+    }
+    return EXIT_SUCCESS;
+}
+
+} // namespace
+
+int main()
+{
+    if (runKnownEuiTest() != EXIT_SUCCESS) {
+        return EXIT_FAILURE;
+    }
+    if (runUnknownIdentityTest() != EXIT_SUCCESS) {
+        return EXIT_FAILURE;
+    }
+    return EXIT_SUCCESS;
+}

Software/components/core/test/health_status_test.cpp

@@ -7,11 +7,6 @@
  * Copyright 2026 Michele Bigi
  * SPDX-License-Identifier: Apache-2.0
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
  * @author  Michele Bigi
  * @date    2026-07-06
  */
@@ -27,18 +22,6 @@
 
 namespace {
 
-/**
- * @brief    expectEqual — assert two strings match.
- *
- * @dname    expectEqual
- * @param    actual    Observed value.
- * @param    expected  Expected value.
- * @return   true when equal.
- * @pubstate none
- *
- * @author   Michele Bigi
- * @date     2026-07-06
- */
 [[nodiscard]] bool expectEqual(const std::string& actual,
                                const std::string& expected)
 {
@@ -49,23 +32,13 @@ namespace {
     return false;
 }
 
-/**
- * @brief    runHealthStatusJsonTest — verify nominal JSON output.
- *
- * @dname    runHealthStatusJsonTest
- * @param    none
- * @return   EXIT_SUCCESS or EXIT_FAILURE.
- * @pubstate none
- *
- * @author   Michele Bigi
- * @date     2026-07-06
- */
 [[nodiscard]] int runHealthStatusJsonTest()
 {
     const core::HealthStatus status =
         core::HealthStatus::ok(core::FirmwareVersion("0.1.0"));
     const std::string json = core::serializeHealthStatusJson(status);
-    if (!expectEqual(json, R"({"status":"ok","fw":"0.1.0"})")) {
+    if (!expectEqual(json,
+                     R"({"status":"ok","fw":"0.1.0","serialNumber":"unknown"})")) {
         return EXIT_FAILURE;
     }
     return EXIT_SUCCESS;
@@ -73,17 +46,6 @@ namespace {
 
 } // namespace
 
-/**
- * @brief    main — host test entry point.
- *
- * @dname    main
- * @param    none
- * @return   EXIT_SUCCESS when all tests pass.
- * @pubstate none
- *
- * @author   Michele Bigi
- * @date     2026-07-06
- */
 int main()
 {
     if (runHealthStatusJsonTest() != EXIT_SUCCESS) {
@@ -96,11 +58,12 @@ int main()
             .si4684Ready = true,
             .adau1701Ready = true,
             .bt1035Ready = true,
-        });
+        },
+        "0004A3123456");
     const std::string chipsJson = core::serializeHealthStatusJson(withChips);
     if (!expectEqual(
             chipsJson,
-            R"({"status":"ok","fw":"0.6.0","chips":{"si4684":true,"adau1701":true,"bt1035":true}})")) {
+            R"({"status":"ok","fw":"0.6.0","serialNumber":"0004A3123456","chips":{"si4684":true,"adau1701":true,"bt1035":true}})")) {
         return EXIT_FAILURE;
     }
     return EXIT_SUCCESS;