diff --git a/include/zdatachannel_service.h b/include/zdatachannel_service.h
index 7015f3a..99ab4f2 100644
--- a/include/zdatachannel_service.h
+++ b/include/zdatachannel_service.h
@@ -87,6 +87,8 @@ static inline uint32_t zdatachannel_block_data_send2(uint8_t* p_data, uint16_t p
   return zdatachannel_block_data_send(p_data, &p_length);
 }
 
+uint32_t zdatachannel_last_rx_data_haspassed_s();
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/zdatachannel_service.c b/src/zdatachannel_service.c
index 9860e01..ad0727f 100644
--- a/src/zdatachannel_service.c
+++ b/src/zdatachannel_service.c
@@ -21,7 +21,8 @@
   } /**< Used vendor specific UUID. */
 
 static zdatachannel_t *p_datachannel;
-//static uint32_t        m_mtusize;
+static uint32_t        m_last_rx_data_tp;
+// static uint32_t        m_mtusize;
 
 static bool notification_enable(uint16_t conn_handle, uint16_t cccd_handle) {
   ret_code_t        err_code;
@@ -48,6 +49,7 @@ static void on_write(zdatachannel_t *p_nus, ble_evt_t const *p_ble_evt) {
   ble_gatts_evt_write_t const *p_evt_write = &p_ble_evt->evt.gatts_evt.params.write;
 
   memset(&evt, 0, sizeof(zdatachannel_evt_t));
+  m_last_rx_data_tp = znordic_getpower_on_s();
 
   if ((p_evt_write->handle == p_nus->cmd_tx_handles.cccd_handle) && (p_evt_write->len == 2)) {
     if (ble_srv_is_notification_enabled(p_evt_write->data)) {
@@ -223,3 +225,12 @@ uint32_t zdatachannel_block_data_send(uint8_t *p_data, uint16_t *p_length) {
 
   return sd_ble_gatts_hvx(p_datachannel->conn_handle, &hvx_params);
 }
+
+uint32_t zdatachannel_last_rx_data_haspassed_s() {  //
+  uint32_t now = znordic_getpower_on_s();
+  if (now > m_last_rx_data_tp) {
+    return now - m_last_rx_data_tp;
+  } else {
+    return 0;
+  }
+}