dashboard: add api polling diagnostics

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

@@ -134,12 +134,22 @@ static void parse_status_json(const String &body)
     if (error) {
         status_model.api_ok = false;
         status_model.http_code = 200;
-        status_model.temps_text = "JSON parse failed";
-        status_model.outputs_text = error.c_str();
-        update_overview_widgets();
+
+        String parse_error;
+        parse_error += "JSON parse failed\n";
+        parse_error += error.c_str();
+
+        Serial.println(parse_error);
+
+        set_label_text_if_changed(battery_label, last_battery_text, "Battery\nJSON parse failed");
+        set_label_text_if_changed(temps_label, last_temps_text, parse_error);
+        set_label_text_if_changed(outputs_label, last_outputs_text, "Outputs\nNo parsed data");
+        set_label_text_if_changed(system_label, last_system_text, parse_error);
         return;
     }
 
+    Serial.println("JSON parse OK");
+
     status_model.api_ok = true;
     status_model.http_code = 200;
 
@@ -308,6 +318,7 @@ static void update_wifi_label()
 static void poll_status_api()
 {
     if (WiFi.status() != WL_CONNECTED) {
+        set_label_text_if_changed(system_label, last_system_text, "API: waiting for WiFi");
         return;
     }
 
@@ -317,18 +328,38 @@ static void poll_status_api()
 
     last_status_poll_ms = millis();
 
+    String requesting;
+    requesting += "API: requesting\n";
+    requesting += "/api/v1/status\n";
+    requesting += "Dashboard IP:\n";
+    requesting += WiFi.localIP().toString();
+    set_label_text_if_changed(system_label, last_system_text, requesting);
+
     Serial.print("GET ");
     Serial.println(CARGO_API_STATUS_URL);
 
     HTTPClient http;
+    http.setTimeout(5000);
     http.begin(CARGO_API_STATUS_URL);
     int code = http.GET();
 
     status_model.http_code = code;
 
+    Serial.print("HTTP code: ");
+    Serial.println(code);
+
     if (code == 200) {
         String body = http.getString();
-        Serial.println("HTTP 200");
+
+        Serial.print("Body length: ");
+        Serial.println(body.length());
+        Serial.println(body);
+
+        String received;
+        received += "API: received\nHTTP: 200\nBytes: ";
+        received += String(body.length());
+        set_label_text_if_changed(system_label, last_system_text, received);
+
         parse_status_json(body);
     } else {
         status_model.api_ok = false;
@@ -341,6 +372,7 @@ static void poll_status_api()
             system += http.errorToString(code);
         }
 
+        Serial.println(system);
         set_label_text_if_changed(system_label, last_system_text, system);
     }
 
@@ -405,6 +437,10 @@ static void create_overland_status_screen()
     temps_label = create_body_label(temps_card);
     outputs_label = create_body_label(outputs_card);
 
+    lv_label_set_text(battery_label, "Waiting for battery data...");
+    lv_label_set_text(temps_label, "Waiting for temp data...");
+    lv_label_set_text(outputs_label, "Waiting for output data...");
+
     wifi_label = create_body_label(system_card);
 
     system_label = lv_label_create(system_card);