Show Flight Controller System ID in the Web Interface

frontend/dronebridge.js

@@ -295,6 +295,13 @@ function get_stats() {
 		} else if (!isNaN(tcp_clients)) {
 			document.getElementById("tcp_connected").innerHTML = tcp_clients + " clients"
 		}
+
+		if (json_data["fc_connected"]) {
+			document.getElementById("fc_sys_id_div").innerHTML = "MAVLink System ID: " + json_data["fc_sys_id"];
+		} else {
+			document.getElementById("fc_sys_id_div").innerHTML = "No Flight Controller connected.";
+		}
+
 		// UDP clients for tooltip
 		let udp_clients_string = ""
 		if (json_data.hasOwnProperty("udp_clients")) {

frontend/index.html

@@ -38,10 +38,10 @@ <h2>Statistics</h2>
                 </div>
             </div>
             <div class="row">
-                <div class="four columns">
-                    <label>received bytes serial port</label>
-                    <div id="read_bytes">-</div>
+                <div id="fc_sys_id_div" class="twelve columns small_text">
                 </div>
+            </div>
+            <div class="row">
                 <div class="four columns">
                     <label>Connected TCP clients</label>
                     <div id="tcp_connected">-</div>
@@ -55,6 +55,12 @@ <h2>Statistics</h2>
                     </div>
                 </div>
             </div>
+            <div class="row">
+                <div class="four columns">
+                    <label>received bytes serial port</label>
+                    <div id="read_bytes">-</div>
+                </div>
+            </div>
         </div>
         <div>
             <h2>Settings</h2>

main/db_mavlink_msgs.c

@@ -18,6 +18,7 @@
  */
 #include <string.h>
 #include <esp_log.h>
+#include <esp_timer.h>
 
 #include "db_mavlink_msgs.h"
 #include "db_parameters.h"
@@ -36,6 +37,22 @@
 #define FASTMAVLINK_ROUTER_COMPONENTS_MAX  5
 
 #define TAG "DB_MAV_MSGS"
+uint8_t DB_MAV_SYS_ID = 1;
+uint32_t last_fc_heartbeat_ms = 0;
+
+/**
+ * Returns true if we recently saw a heartbeat from a flight controller on the serial link
+ */
+bool fc_connected() {
+    return (esp_timer_get_time() / 1000 - last_fc_heartbeat_ms) < 2500;
+}
+
+/**
+ * Returns the current flight controller system ID (last seen)
+ */
+uint8_t db_get_fc_sys_id() {
+    return DB_MAV_SYS_ID;
+}
 
 /**
  * Based on the system architecture and configured wifi mode the ESP32 may have a different role and system id.
@@ -334,6 +351,7 @@ void handle_mavlink_message(fmav_message_t *new_msg, int *tcp_clients, udp_conn_
                     // This means we are connected to the FC since we only parse mavlink on UART and thus only see the
                     // device we are connected to via UART
                     DB_MAV_SYS_ID = new_msg->sysid;
+                    last_fc_heartbeat_ms = esp_timer_get_time() / 1000;
                     // Check if FC is armed and the Wi-Fi switch based on armed status is configured by the user
                     if (DB_PARAM_DIS_RADIO_ON_ARM &&
                     (payload.base_mode & MAV_MODE_FLAG_SAFETY_ARMED ||

main/db_mavlink_msgs.h

@@ -29,6 +29,8 @@
 
 uint8_t db_get_mav_comp_id();
 uint8_t db_get_mav_sys_id();
+bool fc_connected();
+uint8_t db_get_fc_sys_id();
 int8_t db_format_rssi(int8_t signal_strength, int8_t noise_floor);
 uint16_t db_mav_create_heartbeat(uint8_t *buff, fmav_status_t *fmav_status);
 uint16_t db_get_mavmsg_param_value(uint8_t *buff, fmav_status_t *fmav_status, uint16_t param_index, float_int_union *value, uint8_t type, char *param_id);

main/db_serial.c

@@ -46,7 +46,6 @@
 
 #define TAG "DB_SERIAL"
 
-uint8_t DB_MAV_SYS_ID = 1;
 uint32_t serial_total_byte_count = 0;
 uint32_t serial_total_decoded_mav_msgs = 0;
 uint16_t DB_SERIAL_READ_TIMEOUT_MS = DB_SERIAL_READ_TIMEOUT_MS_DEFAULT;

main/http_server.c

@@ -32,6 +32,7 @@
 #include "globals.h"
 #include "main.h"
 #include "db_serial.h"
+#include "db_mavlink_msgs.h"
 
 #define TAG "DB_HTTP_REST"
 #define REST_CHECK(a, str, goto_tag, ...)                                              \
@@ -332,6 +333,8 @@ static esp_err_t system_stats_get_handler(httpd_req_t *req) {
     cJSON_AddNumberToObject(root, "serial_dec_mav_msgs", serial_total_decoded_mav_msgs);
     cJSON_AddNumberToObject(root, "tcp_connected", num_connected_tcp_clients);
     cJSON_AddNumberToObject(root, "udp_connected", udp_conn_list->size);
+    cJSON_AddBoolToObject(root, "fc_connected", fc_connected());
+    cJSON_AddNumberToObject(root, "fc_sys_id", db_get_fc_sys_id());
     // add IP:PORT info on connected UDP clients
     cJSON *udp_clients = cJSON_CreateArray();
     for (int i = 0; i < udp_conn_list->size; i++) {