Examples as Arduino sketches: one folder per device type, each its own endpointId, Wi-Fi with a timeout

Light, DimmableLight, ColorTemperatureLight, ColorLight, TemperatureSensor, ContactSensor, Blind,
Thermostat, Lock, Scene, Doorbell and MultiDevice on the 2.0 API: addCapability(row, instance), one
onDirective() handler, the report helpers, ChangeReports from loop(), a deferred answer for the lock.
Wi-Fi is waited for 30 s, then the sketch says what to check and carries on.

examples/README.md has what each sketch does, its limits and the measured sizes for d1_mini: Light
takes 30,616 bytes of static RAM and 332,565 of flash; all 17 sketches build with 0 warnings.
test/test_examples compares the discovery object of every new sketch: 147 host tests (were 135).
The sketches were compiled, not run on a board.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

examples/TemperatureSensor/TemperatureSensor.ino

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+// TemperatureSensor: a thermometer that Alexa reads, and that tells Alexa when the temperature changed
+// (Alexa.TemperatureSensor).
+//
+// The sensor is a TMP36 on A0 of a Wemos D1 mini, whose A0 takes 0 to 3.2 V; for another sensor replace
+// readTemperature(). The temperature is read every 2 s. A ChangeReport is sent when it differs by more than
+// 0.5 degrees from what Alexa was told last, and at most once a minute.
+#include <Arduino.h>
+#include <ESP8266WiFi.h>
+#include <Alex2ESP.h>
+
+// Wi-Fi and the credentials of your Alex2MQTT account
+const char *WIFI_SSID = "";
+const char *WIFI_PASSWORD = "";
+
+const char *ALEXA_USERNAME = "";
+const char *ALEXA_PASSWORD = "";
+const char *ALEXA_ROOT_TOPIC = "";
+
+const unsigned long READ_EVERY_MS = 2000;
+const unsigned long REPORT_EVERY_MS = 60000;
+const float REPORT_DIFFERENCE = 0.5f; // degrees Celsius
+
+Alex2ESP alexa;
+AlexaDevice *sensor;
+
+float temperature = 0;       // degrees Celsius, as read last
+float reported = 0;          // what the last ChangeReport said
+bool everReported = false;
+unsigned long lastRead = 0;
+unsigned long lastReport = 0;
+
+// Joins the Wi-Fi network and returns after 30 s at the latest. Without a connection the sketch carries on: the
+// ESP8266 keeps trying, and alexa.loop() opens the MQTT session once Wi-Fi is up.
+void connectWiFi()
+{
+  WiFi.mode(WIFI_STA);
+  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
+  Serial.printf("\n[WIFI] Connecting to \"%s\"\n", WIFI_SSID);
+
+  unsigned long started = millis();
+  while (WiFi.status() != WL_CONNECTED && millis() - started < 30000)
+  {
+    delay(100);
+  }
+
+  if (WiFi.status() == WL_CONNECTED)
+  {
+    Serial.printf("[WIFI] Connected, IP address %s\n", WiFi.localIP().toString().c_str());
+  }
+  else
+  {
+    Serial.printf("[WIFI] No connection after 30 s (status %d): check WIFI_SSID and WIFI_PASSWORD. Still trying.\n",
+                  WiFi.status());
+  }
+}
+
+// TMP36: 0.5 V at 0 degrees Celsius, 10 mV per degree
+float readTemperature()
+{
+  float volts = analogRead(A0) * 3.2f / 1023;
+  return (volts - 0.5f) * 100;
+}
+
+void onDirective(AlexaDirective &directive)
+{
+  if (directive.isReportState())
+  {
+    directive.stateReport()
+        .addHealthProp(EndpointHealth::OK)
+        .addTemperatureSensorProp(temperature, TemperatureSensorScale::CELSIUS, millis() - lastRead)
+        .send();
+    return;
+  }
+
+  directive.error(AlexaErrorType::INVALID_DIRECTIVE, "A thermometer takes no directives").send();
+}
+
+void reportChange()
+{
+  bool due = !everReported || millis() - lastReport >= REPORT_EVERY_MS;
+  if (!due || fabs(temperature - reported) <= REPORT_DIFFERENCE || alexa.getState() != Alex2ESPState::CONNECTED)
+  {
+    return;
+  }
+
+  bool sent = sensor->changeReport(AlexaCause::PERIODIC_POLL)
+                  .addTemperatureSensorProp(temperature)
+                  .context()
+                  .addHealthProp(EndpointHealth::OK)
+                  .send();
+  if (sent)
+  {
+    reported = temperature;
+    everReported = true;
+    lastReport = millis();
+  }
+}
+
+void setup()
+{
+  Serial.begin(74880);
+  temperature = readTemperature();
+
+  connectWiFi();
+
+  // MQTT user name, MQTT password, root topic
+  alexa.begin(ALEXA_USERNAME, ALEXA_PASSWORD, ALEXA_ROOT_TOPIC);
+
+  // The name Alexa shows, and the id of the endpoint: every device of an account has its own
+  sensor = alexa.getDevice("Room Temperature", "esp-temperature");
+  sensor->setDisplayCategory(DisplayCategory::TEMPERATURE_SENSOR);
+  sensor->addCapability(AlexaInterfaces::TemperatureSensor)->setProactivelyReported(true);
+  sensor->addCapability(AlexaInterfaces::EndpointHealth);
+  sensor->onDirective(onDirective);
+}
+
+void loop()
+{
+  alexa.loop();
+
+  if (millis() - lastRead >= READ_EVERY_MS)
+  {
+    lastRead = millis();
+    temperature = readTemperature();
+    reportChange();
+  }
+}