diff --git a/src/photo_queue.cpp b/src/photo_queue.cpp
new file mode 100644
index 0000000..90050e7
--- /dev/null
+++ b/src/photo_queue.cpp
@@ -0,0 +1,178 @@
+#include "photo_queue.h"
+#include "immich_client.h"
+#include <ArduinoJson.h>
+#include "config.h"
+
+void PhotoQueue::begin(ImmichClient& client, SettingsManager& settings) {
+    _client = &client;
+    _settings = &settings;
+
+    Settings s = _settings->get();
+    _cursor = s.queue_cursor;
+}
+
+bool PhotoQueue::sync() {
+    if (_client == nullptr || _settings == nullptr) return false;
+
+    Settings s = _settings->get();
+    std::vector<String> newIds;
+
+    // Get selected album IDs
+    std::vector<String> albumIds = getSelectedAlbumIds();
+
+    if (albumIds.empty()) {
+        // "All photos" mode — fetch from all albums
+        auto albums = _client->fetchAlbums();
+        for (auto& album : albums) {
+            auto ids = _client->fetchAlbumAssetIds(album.id);
+            for (auto& id : ids) {
+                newIds.push_back(id);
+            }
+        }
+    } else {
+        // Fetch from selected albums only
+        for (auto& albumId : albumIds) {
+            auto ids = _client->fetchAlbumAssetIds(albumId);
+            for (auto& id : ids) {
+                newIds.push_back(id);
+            }
+        }
+    }
+
+    // Deduplicate
+    std::sort(newIds.begin(), newIds.end());
+    newIds.erase(std::unique(newIds.begin(), newIds.end()), newIds.end());
+
+    if (newIds.empty()) {
+        Serial.println("[queue] No assets found");
+        return false;
+    }
+
+    _queue = newIds;
+
+    // Apply cycling mode
+    switch (s.cycle_mode) {
+        case CycleMode::Random:
+            applyFavoritesWeighting();
+            shuffle();
+            break;
+        case CycleMode::Chronological:
+            sortChronological(false);
+            break;
+        case CycleMode::ReverseChronological:
+            sortChronological(true);
+            break;
+        case CycleMode::FavoritesWeighted:
+            applyFavoritesWeighting();
+            shuffle();
+            break;
+    }
+
+    // Clamp cursor
+    if (_cursor >= _queue.size()) {
+        _cursor = 0;
+    }
+
+    _lastSyncTime = millis();
+    Serial.printf("[queue] Synced: %d assets, cursor at %d\n", _queue.size(), _cursor);
+    return true;
+}
+
+String PhotoQueue::next() {
+    if (_queue.empty()) return "";
+    if (_cursor >= _queue.size()) {
+        _cursor = 0;
+        shuffle();  // Reshuffle on wrap for random mode
+    }
+    String id = _queue[_cursor++];
+
+    // Persist cursor
+    _settings->saveField("queue_cursor", static_cast<uint8_t>(_cursor & 0xFF));
+
+    return id;
+}
+
+String PhotoQueue::random() {
+    if (_queue.empty()) return "";
+    size_t idx = ::random(0, _queue.size());
+    return _queue[idx];
+}
+
+String PhotoQueue::current() {
+    if (_queue.empty()) return "";
+    size_t idx = (_cursor > 0) ? _cursor - 1 : 0;
+    return _queue[idx];
+}
+
+size_t PhotoQueue::size() {
+    return _queue.size();
+}
+
+bool PhotoQueue::needsResync() {
+    if (_lastSyncTime == 0) return true;
+    unsigned long elapsed = millis() - _lastSyncTime;
+    return elapsed >= (QUEUE_RESYNC_HOURS * 3600000UL);
+}
+
+String PhotoQueue::findPortraitPair(size_t startIndex) {
+    // Look ahead up to PORTRAIT_LOOKAHEAD items for another portrait
+    for (size_t i = 1; i <= PORTRAIT_LOOKAHEAD && (startIndex + i) < _queue.size(); i++) {
+        // We'd need asset info to determine portrait status
+        // This will be called by the display task which fetches AssetInfo
+        // Return the ID — caller checks isPortrait from AssetInfo
+        return _queue[startIndex + i];
+    }
+    return "";
+}
+
+void PhotoQueue::shuffle() {
+    for (size_t i = _queue.size() - 1; i > 0; i--) {
+        size_t j = ::random(0, i + 1);
+        std::swap(_queue[i], _queue[j]);
+    }
+}
+
+void PhotoQueue::sortChronological(bool reverse) {
+    // For chronological sort, we'd need timestamps which we don't store in the queue
+    // The IDs from Immich are UUIDs, not sortable by time
+    // For now, keep the order returned by Immich (which is chronological within albums)
+    if (reverse) {
+        std::reverse(_queue.begin(), _queue.end());
+    }
+}
+
+void PhotoQueue::applyFavoritesWeighting() {
+    if (_client == nullptr) return;
+
+    Settings s = _settings->get();
+    if (s.cycle_mode != CycleMode::FavoritesWeighted) return;
+
+    auto favorites = _client->fetchFavoriteAssetIds();
+    // Add favorites 2 more times (total 3× appearance)
+    for (auto& fav : favorites) {
+        // Only add if already in queue
+        bool inQueue = false;
+        for (auto& id : _queue) {
+            if (id == fav) { inQueue = true; break; }
+        }
+        if (inQueue) {
+            _queue.push_back(fav);
+            _queue.push_back(fav);
+        }
+    }
+}
+
+std::vector<String> PhotoQueue::getSelectedAlbumIds() {
+    std::vector<String> ids;
+    Settings s = _settings->get();
+
+    JsonDocument doc;
+    DeserializationError err = deserializeJson(doc, s.albums_json);
+    if (err) return ids;
+
+    JsonArray arr = doc.as<JsonArray>();
+    for (JsonVariant v : arr) {
+        ids.push_back(v.as<String>());
+    }
+    return ids;
+}
diff --git a/src/photo_queue.h b/src/photo_queue.h
new file mode 100644
index 0000000..39476aa
--- /dev/null
+++ b/src/photo_queue.h
@@ -0,0 +1,32 @@
+#pragma once
+
+#include <Arduino.h>
+#include <vector>
+#include "settings.h"
+
+class ImmichClient;
+
+class PhotoQueue {
+public:
+    void begin(ImmichClient& client, SettingsManager& settings);
+    bool sync();
+    String next();
+    String random();
+    String current();
+    size_t size();
+    bool needsResync();
+    String findPortraitPair(size_t startIndex);
+
+private:
+    ImmichClient* _client = nullptr;
+    SettingsManager* _settings = nullptr;
+
+    std::vector<String> _queue;
+    size_t _cursor = 0;
+    unsigned long _lastSyncTime = 0;
+
+    void shuffle();
+    void sortChronological(bool reverse);
+    void applyFavoritesWeighting();
+    std::vector<String> getSelectedAlbumIds();
+};
diff --git a/test/test_native/test_photo_queue.cpp b/test/test_native/test_photo_queue.cpp
new file mode 100644
index 0000000..df9c768
--- /dev/null
+++ b/test/test_native/test_photo_queue.cpp
@@ -0,0 +1,106 @@
+#include <unity.h>
+#include <vector>
+#include <algorithm>
+#include <cstdlib>
+#include <cstring>
+
+// Minimal test of queue cycling logic (extracted, platform-independent)
+// We test the shuffling and cycling algorithms without hardware dependencies
+
+struct QueueState {
+    std::vector<std::string> ids;
+    size_t cursor;
+};
+
+// Simulate random cycling: advance through shuffled list
+std::string advanceRandom(QueueState& state) {
+    if (state.ids.empty()) return "";
+    if (state.cursor >= state.ids.size()) {
+        state.cursor = 0;  // Wrap around (would reshuffle in real impl)
+    }
+    return state.ids[state.cursor++];
+}
+
+// Simulate chronological: just advance sequentially (assumes pre-sorted)
+std::string advanceChrono(QueueState& state) {
+    if (state.ids.empty()) return "";
+    if (state.cursor >= state.ids.size()) {
+        state.cursor = 0;
+    }
+    return state.ids[state.cursor++];
+}
+
+// Favorites weighting: insert duplicates
+std::vector<std::string> applyFavoritesWeight(
+    const std::vector<std::string>& all,
+    const std::vector<std::string>& favorites,
+    int weight) {
+
+    std::vector<std::string> result = all;
+    for (const auto& fav : favorites) {
+        for (int i = 1; i < weight; i++) {
+            result.push_back(fav);
+        }
+    }
+    return result;
+}
+
+void test_advance_random_no_repeats_until_wrap() {
+    QueueState state;
+    state.ids = {"a", "b", "c", "d", "e"};
+    state.cursor = 0;
+
+    std::vector<std::string> seen;
+    for (size_t i = 0; i < state.ids.size(); i++) {
+        std::string id = advanceRandom(state);
+        // Should not have seen this one yet
+        TEST_ASSERT_TRUE(std::find(seen.begin(), seen.end(), id) == seen.end());
+        seen.push_back(id);
+    }
+    TEST_ASSERT_EQUAL(5, seen.size());
+}
+
+void test_advance_wraps_at_end() {
+    QueueState state;
+    state.ids = {"a", "b", "c"};
+    state.cursor = 0;
+
+    advanceRandom(state);  // a
+    advanceRandom(state);  // b
+    advanceRandom(state);  // c
+    std::string wrapped = advanceRandom(state);  // wraps to a
+    TEST_ASSERT_EQUAL_STRING("a", wrapped.c_str());
+}
+
+void test_empty_queue_returns_empty() {
+    QueueState state;
+    state.cursor = 0;
+    std::string result = advanceRandom(state);
+    TEST_ASSERT_EQUAL_STRING("", result.c_str());
+}
+
+void test_favorites_weighting() {
+    std::vector<std::string> all = {"a", "b", "c"};
+    std::vector<std::string> favs = {"b"};
+    auto weighted = applyFavoritesWeight(all, favs, 3);
+    // "b" should appear 3 times total (1 original + 2 extra)
+    int count = 0;
+    for (const auto& id : weighted) {
+        if (id == "b") count++;
+    }
+    TEST_ASSERT_EQUAL(3, count);
+    TEST_ASSERT_EQUAL(5, weighted.size());  // 3 original + 2 extra
+}
+
+void setUp() {}
+void tearDown() {}
+
+int main() {
+    UNITY_BEGIN();
+    RUN_TEST(test_advance_random_no_repeats_until_wrap);
+    RUN_TEST(test_advance_wraps_at_end);
+    RUN_TEST(test_empty_queue_returns_empty);
+    RUN_TEST(test_favorites_weighting);
+    UNITY_END();
+    return 0;
+}