diff --git a/firmware/src/main.cpp b/firmware/src/main.cpp
index 27f3768..54e6cda 100644
--- a/firmware/src/main.cpp
+++ b/firmware/src/main.cpp
@@ -1,3 +1,144 @@
+// firmware/src/main.cpp
 #include <Arduino.h>
-void setup() {}
-void loop() {}
+#include <WiFi.h>
+#include "config.h"
+#include "provisioning.h"
+#include "camera.h"
+#include "cv.h"
+#include "ble_scanner.h"
+#include "reporter.h"
+
+// LED on GPIO2 (TimerCamera-F built-in LED) — verify against board schematic
+// Factory reset: hold GPIO37 (BOOT button) for 5 seconds
+#define LED_PIN       2
+#define BUTTON_PIN   37
+#define FACTORY_RESET_HOLD_MS 5000
+
+#define CAM_FPS           5
+#define CAM_INTERVAL_MS   (1000 / CAM_FPS)
+#define REPORT_INTERVAL_S 3600
+
+static DeviceConfig g_cfg;
+static CVState      g_cv;
+
+// LED: simple on/off — blink patterns can be added later
+static void led_set(bool on) { digitalWrite(LED_PIN, on ? HIGH : LOW); }
+
+static void check_factory_reset() {
+    if (digitalRead(BUTTON_PIN) != LOW) return;
+    uint32_t held = millis();
+    while (digitalRead(BUTTON_PIN) == LOW) {
+        if (millis() - held >= FACTORY_RESET_HOLD_MS) {
+            config_clear_wifi();
+            ESP.restart();
+        }
+        delay(50);
+    }
+}
+
+// Camera + CV task — runs on core 1 at 5 fps
+static void task_camera(void*) {
+    uint8_t frame[CV_PIXELS];
+    while (true) {
+        if (camera_capture_96(frame)) {
+            cv_process(g_cv, frame, g_cfg.line_offset);
+        }
+        vTaskDelay(pdMS_TO_TICKS(CAM_INTERVAL_MS));
+    }
+}
+
+// Hourly reporter task — runs on core 0
+static void task_reporter(void*) {
+    uint32_t last_report_ts = (uint32_t)(time(nullptr));
+    while (true) {
+        vTaskDelay(pdMS_TO_TICKS(10000)); // check every 10s
+
+        uint32_t now = (uint32_t)(time(nullptr));
+        // Skip if NTP not synced or hour not elapsed
+        if (now < 1700000000UL || (now - last_report_ts) < REPORT_INTERVAL_S) continue;
+
+        uint32_t period_start = last_report_ts;
+        uint32_t period_end   = now;
+        last_report_ts = now;
+
+        // Pause BLE during upload
+        ble_scanner_pause();
+        led_set(true); // yellow indicator (single LED: on = uploading)
+
+        CameraHourlyRecord cam_rec = {period_start, period_end,
+                                      g_cv.entries, g_cv.exits};
+        cv_reset_counts(g_cv);
+
+        BLEHourlyRecord ble_rec = ble_scanner_collect(period_start, period_end);
+
+        reporter_submit_camera(g_cfg, cam_rec);
+        reporter_submit_ble(g_cfg, ble_rec);
+        reporter_heartbeat(g_cfg, millis() / 1000, WiFi.RSSI());
+
+        ble_scanner_resume();
+        led_set(false);
+    }
+}
+
+void setup() {
+    Serial.begin(115200);
+    pinMode(LED_PIN, OUTPUT);
+    pinMode(BUTTON_PIN, INPUT_PULLUP);
+    led_set(true); // on = booting
+
+    if (!config_load(g_cfg)) {
+        Serial.println("FATAL: device_id/location_id/hmac_secret not provisioned");
+        while (true) { delay(500); led_set(!digitalRead(LED_PIN)); } // fast blink
+    }
+
+    // Connect to WiFi
+    if (!config_has_wifi()) {
+        provisioning_run();
+        ESP.restart();
+    }
+
+    WiFi.begin(g_cfg.wifi_ssid.c_str(), g_cfg.wifi_pass.c_str());
+    uint32_t wifi_start = millis();
+    while (WiFi.status() != WL_CONNECTED && millis() - wifi_start < 15000) {
+        check_factory_reset();
+        delay(200);
+    }
+
+    if (WiFi.status() != WL_CONNECTED) {
+        // Saved creds failed — re-provision
+        provisioning_run();
+        ESP.restart();
+    }
+
+    led_set(false); // off = connected
+
+    // NTP sync (UTC)
+    configTime(0, 0, "pool.ntp.org", "time.nist.gov");
+
+    cv_init(g_cv);
+
+    if (!camera_init()) {
+        Serial.println("FATAL: camera init failed");
+        while (true) delay(1000);
+    }
+
+    ble_scanner_start();
+
+    xTaskCreatePinnedToCore(task_camera,   "cam",  4096, nullptr, 2, nullptr, 1);
+    xTaskCreatePinnedToCore(task_reporter, "rep",  8192, nullptr, 1, nullptr, 0);
+}
+
+void loop() {
+    check_factory_reset();
+
+    if (WiFi.status() != WL_CONNECTED) {
+        led_set(true); // on = no WiFi
+        WiFi.reconnect();
+        delay(5000);
+        if (WiFi.status() == WL_CONNECTED) {
+            led_set(false);
+            reporter_flush(g_cfg);
+        }
+    }
+    delay(1000);
+}