Can use bssid and channel to save power

It's much faster to connect to wifi, so less power hungry

deepSleep.ino

@@ -37,6 +37,8 @@ Adafruit_MQTT_Publish *mqtt_voltage;
 
 const char *ssid     = "XXXXX";
 const char *password = "XXXXX";
+uint8_t bssid[6] = {0x14, 0x0C, 0x76, 0xB1, 0x37, 0x32};
+int32_t channel = 11; //0 for Auto
 
 ADC_MODE(ADC_VCC);
 void setup()
@@ -95,9 +97,9 @@ int mqttConnect(float h, float t)
   mqtt_temp     = new Adafruit_MQTT_Publish(mqtt, TEMPERATURE_FEED_FORMAT, 0);
   mqtt_pressure = new Adafruit_MQTT_Publish(mqtt, HUMIDITY_FEED_FORMAT, 0);
   mqtt_voltage = new Adafruit_MQTT_Publish(mqtt, VOLTAGE_FEED_FORMAT, 0);
-  if(!mqtt_temp->publish(t)){
+  if (!mqtt_temp->publish(t)) {
     Serial.println("failed to send temp");
-    }
+  }
   mqtt_pressure->publish(h);
   mqtt_voltage->publish(ESP.getVcc());
   mqtt->disconnect();
@@ -135,11 +137,15 @@ int doMeasure()
   IPAddress gateway(192, 168, 0, 254);
   IPAddress subnet(255, 255, 255, 0);
   WiFi.config(ip, gateway, subnet);
-  WiFi.begin(ssid, password);
+  WiFi.begin(ssid, password, channel, bssid);
 
+  int retry = 10;
   while (WiFi.status() != WL_CONNECTED) {
     delay(100);
     Serial.print(".");
+    if (retry < 0)
+      continue;
+    retry --;
   }
 
 
@@ -148,8 +154,8 @@ int doMeasure()
   Serial.println("IP address: ");
   Serial.println(WiFi.localIP());
   mqttConnect(h, t);
-  if (WiFiOff()){
-  //if (WiFi.forceSleepBegin(0)) {
+  if (WiFiOff()) {
+    //if (WiFi.forceSleepBegin(0)) {
     Serial.println("Fail to set sleep mode");
   }
   return 0;