An example of sending data to the server using the Light Sleep mode.

examples/Boards_WiFi/ESP8266_Standalone_WiFi_with_sleep/ESP8266_Standalone_WiFi_with_sleep.ino

@@ -0,0 +1,243 @@
+/*************************************************************
+  Download latest Blynk library here:
+    https://github.com/blynkkk/blynk-library/releases/latest
+  Blynk is a platform with iOS and Android apps to control
+  Arduino, Raspberry Pi and the likes over the Internet.
+  You can easily build graphic interfaces for all your
+  projects by simply dragging and dropping widgets.
+    Downloads, docs, tutorials: http://www.blynk.cc
+    Sketch generator:           http://examples.blynk.cc
+    Blynk community:            http://community.blynk.cc
+    Follow us:                  http://www.fb.com/blynkapp
+                                http://twitter.com/blynk_app
+  Blynk library is licensed under MIT license
+  This example code is in public domain.
+ *************************************************************
+  This example runs directly on ESP8266 chip.
+  Note: This requires ESP8266 support package:
+    https://github.com/esp8266/Arduino
+  Please be sure to select the right ESP8266 module
+  in the Tools -> Board menu!
+ *************************************************************/
+
+#define BLYNK_PRINT Serial
+#include <ESP8266WiFi.h>
+#include <ESP8266mDNS.h>
+#include <WiFiUdp.h>
+#include <ArduinoOTA.h>
+#include <BlynkSimpleEsp8266.h>
+#include <TimeLib.h>
+#include <WidgetRTC.h>
+
+char auth[] = "YourAuthToken";
+char ssid[] = "YourNetworkName";
+char pass[] = "YourPassword";
+char OTApass[] = "YourOTAPassword";  // any password for OTA security access
+
+int RSSIvalue = 0;
+float Voltage=0.00f;
+unsigned long Timer_5000 = 0;
+byte mac[6];
+
+
+#define PIN_RSSI V2
+#define PIN_UBAT V3
+#define LED      2
+
+ADC_MODE (ADC_VCC);
+WidgetTerminal terminal(V1);
+WidgetRTC rtc;
+
+void myTimerEvent()
+{
+  Blynk.virtualWrite(PIN_RSSI, RSSIvalue); 
+  Blynk.virtualWrite(PIN_UBAT, Voltage);  
+}
+
+BLYNK_CONNECTED() {
+  // Synchronize time on connection
+  rtc.begin();
+}
+
+
+void setup()
+{
+
+  Serial.begin(9600);    // can be change for faster, ex. 115200, or 921600 
+  Serial.println("Blynk.begin");  
+  terminal.println("   -----> Blynk.begin");
+
+  Blynk_init();
+  if (WiFi.status() != WL_CONNECTED) ESP.restart();
+
+  rtc.begin();
+  terminal.print(currentTime());
+  terminal.println(" Connected to server");
+  terminal.println(WiFi.localIP());
+  WiFi.macAddress(mac);  
+  terminal.print("MAC: ");
+  terminal.print(mac[5],HEX);
+  terminal.print(":");
+  terminal.print(mac[4],HEX);
+  terminal.print(":");
+  terminal.print(mac[3],HEX);
+  terminal.print(":");
+  terminal.print(mac[2],HEX);
+  terminal.print(":");
+  terminal.print(mac[1],HEX);
+  terminal.print(":");
+  terminal.println(mac[0],HEX);
+
+  pinMode(LED,  OUTPUT);  
+  digitalWrite(LED, HIGH);
+
+  Serial.println("Blynk Started OK...");
+
+  OTA_init();    
+
+  Voltage = (ESP.getVcc()-210.0f)/1000.0f;           //  [-210.0f] - correction for real measurement with voltmeter
+
+  myTimerEvent();                                    // send data to server
+  terminal.flush();
+
+  Timer_5000 = millis();
+
+}
+
+String currentTime() {
+  char str[8];
+  sprintf( str, "%02d:%02d:%02d", hour(), minute(), second() );
+  return str;
+}
+
+void Blynk_init() {
+  int conB_count = 5;
+  while ((!Blynk.begin_t(auth, ssid, pass, IPAddress(172,18,1,111), 8080, 30000)) && (conB_count>0)) --conB_count;  // Should change IPAddress(172,18,1,111) to address of your server
+}
+
+void OTA_init() {
+  ArduinoOTA.setHostname("MyESP");         //Set OTA host name (optional)
+  ArduinoOTA.setPassword(OTApass);         //Set OTA host password (optional)
+  ArduinoOTA.onStart([]() {
+    String type;
+    if (ArduinoOTA.getCommand() == U_FLASH) {
+      type = "sketch";
+    } else { // U_FS
+      type = "filesystem";
+    }
+    Serial.println("Start updating " + type);
+  });
+  ArduinoOTA.onEnd([]() {
+    Serial.println("\nEnd");
+  //  terminal.println("\nEnd");
+  });
+  ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
+    Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
+  });
+  ArduinoOTA.onError([](ota_error_t error) {
+    Serial.printf("Error[%u]: ", error);
+    if (error == OTA_AUTH_ERROR) {
+      Serial.println("Auth Failed");
+    } else if (error == OTA_BEGIN_ERROR) {
+      Serial.println("Begin Failed");
+    } else if (error == OTA_CONNECT_ERROR) {
+      Serial.println("Connect Failed");
+    } else if (error == OTA_RECEIVE_ERROR) {
+      Serial.println("Receive Failed");
+    } else if (error == OTA_END_ERROR) {
+      Serial.println("End Failed");
+    }
+  });
+  ArduinoOTA.begin();
+
+  terminal.print(currentTime());
+  Serial.println("OTA Started OK...");
+  terminal.println(" OTA Started OK...");
+}
+
+void connectBlynk() {
+  Serial.print(currentTime());
+  Serial.println(F("  Woke up!"));    
+  Serial.flush();
+}
+
+void loop()
+{
+
+  ArduinoOTA.handle();
+  Blynk.run();
+  if ((Timer_5000+5000) < millis()) {
+    ESPsleep();                                   // ESP will run 5 sec for detect OTA request 
+    Timer_5000 = millis();    
+  }
+
+}
+
+void ESPsleep() {
+
+  terminal.print(currentTime());
+  terminal.println("  Sleeping 90 sec...");
+  Serial.println("Sleeping 90 sec...");
+  terminal.flush();
+  delay(100);
+  Blynk.disconnect();
+  WiFi.mode(WIFI_OFF);                  // you must turn the modem off; using disconnect won't work
+  digitalWrite(LED, HIGH);              // turn the LED off so they know the CPU isn't running
+  extern os_timer_t *timer_list;
+  timer_list = nullptr;                 // stop (but don't disable) the 4 OS timers
+  wifi_fpm_set_sleep_type(LIGHT_SLEEP_T);
+  gpio_pin_wakeup_enable(GPIO_ID_PIN(0), GPIO_PIN_INTR_LOLEVEL);  // GPIO wakeup (optional)
+  wifi_fpm_set_wakeup_cb(connectBlynk); // set wakeup callback
+  wifi_fpm_open();
+  wifi_fpm_do_sleep(90E6);              // Sleep range = 10000 ~ 268,435,454 uS (0xFFFFFFE, 2^28-1)
+  delay(90e3 + 1);                      // delay needs to be 1 mS longer than sleep or it only goes into Modem Sleep
+
+  digitalWrite(LED, LOW);      // LED twice flash for sleep off
+  delay(50);
+  digitalWrite(LED, HIGH);
+  delay(50);
+  digitalWrite(LED, LOW);
+  delay(50);
+  digitalWrite(LED, HIGH);
+
+  Blynk_init();
+  if (WiFi.status() != WL_CONNECTED) {
+    Serial.println("Connection Failed! Rebooting...");
+    digitalWrite(LED, LOW);
+    delay(250);
+    digitalWrite(LED, HIGH);
+    delay(100);
+    ESP.restart();
+  } else {
+    rtc.begin();    
+    terminal.print(currentTime());
+    terminal.print(F("  Wokeup with "));
+    terminal.print("WiFi ");
+    terminal.print(6-conB_count);
+    terminal.println(" Blynk atmpts");
+    terminal.flush();
+    ArduinoOTA.begin();
+    Serial.println("Connection restored OK...");
+    terminal.print(currentTime());
+    terminal.println("  Connection restored. OTA available.");
+    terminal.print(currentTime());
+    terminal.print("  IP: ");
+    terminal.println(WiFi.localIP());
+    terminal.flush();
+  }  
+  Serial.println("Data sending started...");
+  terminal.print(currentTime());
+  terminal.println("  Data sending started...");
+  terminal.flush();
+  digitalWrite(LED, LOW);
+  delay(25);
+  digitalWrite(LED, HIGH);
+  Voltage = (ESP.getVcc()-210.0f)/1000.0f;
+  RSSIvalue = WiFi.RSSI();
+  // And other your measurements
+  myTimerEvent();                                 // Send datas
+  terminal.print(currentTime());
+  terminal.println("  Data Sended OK...");
+  terminal.flush();
+  Serial.println("Data Sended OK...");
+}

src/BlynkSimpleEsp8266.h

@@ -55,6 +55,31 @@ class BlynkWifi
         (void)myip; // Eliminate warnings about unused myip
         BLYNK_LOG_IP("IP: ", myip);
     }
+
+    bool connectWiFi_t(const char* ssid, 
+                       const char* pass, 
+                       uint16_t timeout = 10000)
+    {
+        BLYNK_LOG2(BLYNK_F("Connecting to "), ssid);
+        WiFi.mode(WIFI_STA);
+        if (WiFi.status() != WL_CONNECTED) {
+          if (pass && strlen(pass)) {
+            WiFi.begin(ssid, pass);
+          } else {
+            WiFi.begin(ssid);
+          }
+        }
+		int WFB = timeout / 500;  // set default 20 cycles 
+        while ((WiFi.status() != WL_CONNECTED) && (WFB>0)) {
+          BlynkDelay(500);
+		  --WFB;
+        }
+        if (WiFi.status() != WL_CONNECTED) return false;		
+        BLYNK_LOG1(BLYNK_F("Connected to WiFi"));
+        IPAddress myip = WiFi.localIP();
+        BLYNK_LOG_IP("IP: ", myip);
+		return true;
+    }
 
     void config(const char* auth,
                 const char* domain = BLYNK_DEFAULT_DOMAIN,
@@ -93,6 +118,22 @@ class BlynkWifi
         config(auth, ip, port);
         while(this->connect() != true) {}
     }
+
+    bool begin_t(const char* auth,
+                 const char* ssid,
+                 const char* pass,
+                 IPAddress   ip,
+                 uint16_t    port   = BLYNK_DEFAULT_PORT,
+			     uint16_t wifi_timeout = 30000)
+    {
+		if (WiFi.status() != WL_CONNECTED) {
+		  uint16_t connect_count = wifi_timeout / 10000;
+          while ((connectWiFi_t(ssid, pass, wifi_timeout / 3)) && (connect_count>0)) --connect_count;   
+		  if (WiFi.status() != WL_CONNECTED) return false;
+		}
+        config(auth, ip, port);
+		return this->connect();
+    } 
 
 };