Added PowerSaving for sensor firmware

examples/simple_sensor/SensorMesh.cpp

@@ -979,3 +979,8 @@ void SensorMesh::loop() {
     dirty_contacts_expiry = 0;
   }
 }
+
+// To check if there is pending work
+bool SensorMesh::hasPendingWork() const {
+  return _mgr->getOutboundTotal() > 0;
+}

examples/simple_sensor/SensorMesh.h

@@ -52,6 +52,9 @@ public:
   void begin(FILESYSTEM* fs);
   void loop();
   void handleCommand(uint32_t sender_timestamp, char* command, char* reply);
+  
+  // To check if there is pending work
+  bool hasPendingWork() const;
 
   // CommonCLI callbacks
   const char* getFirmwareVer() override { return FIRMWARE_VERSION; }

examples/simple_sensor/main.cpp

@@ -52,6 +52,9 @@ void halt() {
 
 static char command[160];
 
+// For power saving
+unsigned long POWERSAVING_FIRSTSLEEP_SECS = 120; // The first sleep (if enabled) from boot
+
 void setup() {
   Serial.begin(115200);
   delay(1000);
@@ -166,4 +169,19 @@ void loop() {
 #ifdef HAS_EXTERNAL_WATCHDOG
   external_watchdog.loop();
 #endif
+
+  if (the_mesh.getNodePrefs()->powersaving_enabled && !the_mesh.hasPendingWork()) {
+#if defined(NRF52_PLATFORM)
+    board.sleep(0); // nrf ignores seconds param, sleeps whenever possible
+#else
+    if (the_mesh.millisHasNowPassed(POWERSAVING_FIRSTSLEEP_SECS * 1000)) { // To check if it is time to sleep
+      board.sleep(30); // Sleep. Wake up after a while or when receiving a LoRa packet
+    }
+#endif
+  }
+
+  if (the_mesh.getNodePrefs()->reboot_interval > 0 &&
+      the_mesh.millisHasNowPassed(the_mesh.getNodePrefs()->reboot_interval * 3600000)) {
+    board.reboot();
+  }
 }