add network maintainer example

Author: ZeroBitsTech

examples/NetworkMaintainer/NetworkMaintainer.ino

@@ -0,0 +1,91 @@
+#include <ZeroKernel.h>
+#include <modules/net/ZeroWiFiMaintainer.h>
+
+#if defined(ARDUINO_ARCH_ESP8266)
+#include <ESP8266WiFi.h>
+#elif defined(ARDUINO_ARCH_ESP32)
+#include <WiFi.h>
+#else
+#error "NetworkMaintainer example requires ESP8266 or ESP32."
+#endif
+
+using zerokernel::Kernel;
+using zerokernel::modules::net::ZeroWiFiMaintainer;
+
+namespace {
+
+const char* kSsid = "replace-me";
+const char* kPassword = "replace-me";
+const Kernel::TopicKey kWiFiStateTopic = Kernel::makeTopicKey("wifi.link");
+
+ZeroWiFiMaintainer g_wifiMaintainer;
+
+bool isWiFiConnected() {
+  return WiFi.status() == WL_CONNECTED;
+}
+
+void connectWiFi() {
+  if (WiFi.status() != WL_CONNECTED) {
+    WiFi.begin(kSsid, kPassword);
+  }
+}
+
+void disconnectWiFi() {
+  if (WiFi.status() == WL_CONNECTED) {
+    WiFi.disconnect();
+  }
+}
+
+void onWiFiState(const char*, const Kernel::EventValue& value) {
+  if (value.type != Kernel::kEventBool) {
+    return;
+  }
+
+  Serial.print("wifi.state => ");
+  Serial.println(value.boolValue ? "connected" : "disconnected");
+}
+
+void heartbeatTask() {
+  const Kernel::KernelStats stats = ZeroKernel.getStats();
+
+  Serial.print("heartbeat runs=");
+  Serial.print(stats.taskExecutions);
+  Serial.print(" events=");
+  Serial.print(stats.eventsDelivered);
+  Serial.print(" wifi_attempts=");
+  Serial.print(g_wifiMaintainer.connectAttempts());
+  Serial.print(" reconnects=");
+  Serial.println(g_wifiMaintainer.reconnectTransitions());
+}
+
+}  // namespace
+
+void setup() {
+  Serial.begin(115200);
+  delay(50);
+
+  WiFi.mode(WIFI_STA);
+  WiFi.setAutoReconnect(false);
+  WiFi.persistent(false);
+
+  ZeroKernel.begin();
+  ZeroKernel.subscribeTypedFast(kWiFiStateTopic, onWiFiState);
+
+  ZeroWiFiMaintainer::Config config;
+  config.pollIntervalMs = 250;
+  config.retryBaseMs = 1000;
+  config.retryMaxMs = 15000;
+  config.manageCapabilities = true;
+  config.capabilityMask = Kernel::kCapNetwork;
+  config.stateTopicKey = kWiFiStateTopic;
+
+  g_wifiMaintainer.begin(ZeroKernel, isWiFiConnected, connectWiFi, disconnectWiFi, config);
+
+  ZeroKernel.addTask("Heartbeat", heartbeatTask, 1000, 0);
+  ZeroKernel.setTaskPriority("Heartbeat", Kernel::kPriorityLow);
+}
+
+void loop() {
+  ZeroKernel.tick();
+  g_wifiMaintainer.tick();
+}