dashboard: prevent overlapping status polls

firmware/esp32-s3-dashboard/dashboard_config.h

@@ -1,6 +1,6 @@
 #pragma once
 
-static const char *DASHBOARD_VERSION = "0.0.10-api-timing";
+static const char *DASHBOARD_VERSION = "0.0.11-no-overlap-polling";
 
 // Update these if your Cargo ESP AP credentials are different.
 static const char *CARGO_WIFI_SSID = "OverlandController";

firmware/esp32-s3-dashboard/esp32-s3-dashboard.ino

@@ -30,6 +30,8 @@ static unsigned long last_wifi_attempt_ms = 0;
 static unsigned long last_wifi_label_update_ms = 0;
 static unsigned long last_status_poll_ms = 0;
 static unsigned long last_metadata_poll_ms = 0;
+static bool api_request_in_progress = false;
+static bool fast_status_refresh_requested = false;
 
 static String last_battery_text;
 static String last_temps_text;
@@ -44,9 +46,9 @@ static String on_off(bool value)
     return value ? "ON" : "OFF";
 }
 
-static void force_status_poll_now()
+static void request_fast_status_refresh()
 {
-    last_status_poll_ms = 0;
+    fast_status_refresh_requested = true;
 }
 
 static bool post_relay_state(const String &relay_id, bool state)
@@ -122,8 +124,7 @@ static void relay_button_event_cb(lv_event_t *event)
         optimistic_text += "\nRefreshing status...";
         set_label_text_if_changed(system_label, last_system_text, optimistic_text);
 
-        force_status_poll_now();
-        poll_status_api();
+        request_fast_status_refresh();
     } else {
         relay_states[index] = previous_state;
         update_relay_buttons();
@@ -463,11 +464,19 @@ static void update_wifi_label()
 
 static bool fetch_status_fields(const char *url, const char *label)
 {
+    if (api_request_in_progress) {
+        Serial.print("Skipping ");
+        Serial.print(label);
+        Serial.println(": request already in progress");
+        return false;
+    }
+
     if (WiFi.status() != WL_CONNECTED) {
         set_label_text_if_changed(system_label, last_system_text, "API: waiting for WiFi");
         return false;
     }
 
+    api_request_in_progress = true;
     unsigned long start_ms = millis();
 
     Serial.print("GET ");
@@ -521,6 +530,7 @@ static bool fetch_status_fields(const char *url, const char *label)
         Serial.println(body.length());
 
         http.end();
+        api_request_in_progress = false;
         return true;
     }
 
@@ -547,6 +557,7 @@ static bool fetch_status_fields(const char *url, const char *label)
     set_label_text_if_changed(system_label, last_system_text, system);
 
     http.end();
+    api_request_in_progress = false;
     return false;
 }
 
@@ -557,7 +568,8 @@ static void poll_status_api()
         return;
     }
 
-    if (millis() - last_status_poll_ms >= 2000) {
+    if (fast_status_refresh_requested || millis() - last_status_poll_ms >= 2000) {
+        fast_status_refresh_requested = false;
         last_status_poll_ms = millis();
         fetch_status_fields(CARGO_API_FAST_STATUS_URL, "fast status");
     }