 
 static inline void stop_motor() {
   digitalWrite(PIN_MOTOR, HIGH);
+}
+
+static inline void start_buzzer() {
+  g_buzzer_on = true;
+  digitalWrite(PIN_BUZZER, HIGH);
+}
+
+static inline void stop_buzzer() {
+  digitalWrite(PIN_BUZZER, LOW);
+  g_buzzer_on = false;
 }
 
 static inline bool lock_status_on() {

  Serial.println("unlocking");
}

void handle_msg(String &msg) {
  StaticJsonBuffer<JSON_BUF_SIZE> json_buf;
  JsonObject& root = json_buf.parseObject(msg);
  if (!root.success()) {


static gpsSentenceInfoStruct g_gps_info;
static unsigned long g_last_get_gps_ms = 0;
static unsigned long g_buzzer_on_ms = 0;
static uint32_t g_buzzer_duration = 0;
static bool g_buzzer_on = false;

static unsigned long g_check_net_ms = 0;

static inline void start_motor() {
  digitalWrite(PIN_MOTOR, LOW);
