From 3386806af70e9357de8bef6ff19e9754ba4901f0 Mon Sep 17 00:00:00 2001
From: TD-er <gijs.noorlander@gmail.com>
Date: Tue, 12 Jan 2021 16:54:09 +0100
Subject: [PATCH] [Minimal OTA] Make minimal OTA build fit again

---
 src/ESPEasy_common.h                          |  6 --
 src/_C018.ino                                 |  2 +-
 src/_N001_Email.ino                           |  8 +-
 src/_P020_Ser2Net.ino                         |  2 +-
 src/_P022_PCA9685.ino                         |  4 +-
 src/_P026_Sysinfo.ino                         | 16 +---
 src/_P042_Candle.ino                          |  2 +-
 src/_P095_ILI9341.ino                         |  2 +-
 src/src/Commands/InternalCommands.cpp         |  6 ++
 src/src/Commands/Notifications.cpp            |  4 +
 src/src/Commands/Notifications.h              |  6 ++
 src/src/Commands/wd.cpp                       |  3 +
 src/src/Commands/wd.h                         |  6 ++
 src/src/CustomBuild/define_plugin_sets.h      |  2 +-
 src/src/DataStructs/C013_p2p_dataStructs.cpp  |  3 +
 src/src/DataStructs/C013_p2p_dataStructs.h    |  3 +-
 .../DataStructs/GpioFactorySettingsStruct.cpp | 19 ++++-
 .../DataStructs/GpioFactorySettingsStruct.h   |  1 +
 src/src/ESPEasyCore/ESPEasyNetwork.cpp        |  4 +-
 src/src/ESPEasyCore/ESPEasyRules.cpp          | 82 +++----------------
 src/src/ESPEasyCore/ESPEasyRules.h            |  1 -
 src/src/ESPEasyCore/ESPEasyWifi.cpp           | 13 ++-
 .../ESPEasyCore/ESPEasyWifi_ProcessEvent.cpp  |  6 +-
 src/src/Globals/Plugins.cpp                   |  8 +-
 src/src/Globals/Services.h                    | 20 +++--
 src/src/Helpers/ESPEasy_FactoryDefault.cpp    |  2 +
 src/src/Helpers/ESPEasy_checks.cpp            |  8 +-
 src/src/Helpers/Hardware.cpp                  | 21 ++++-
 src/src/Helpers/MDNS_Helper.cpp               |  3 +-
 src/src/Helpers/StringConverter.cpp           | 10 ++-
 src/src/Helpers/StringGenerator_GPIO.cpp      |  4 +-
 src/src/Helpers/SystemVariables.cpp           |  4 +-
 src/src/Helpers/_CPlugin_Helper_webform.cpp   |  2 +-
 src/src/WebServer/AdvancedConfigPage.cpp      |  3 +-
 src/src/WebServer/FactoryResetPage.cpp        | 13 ++-
 src/src/WebServer/FileList.cpp                |  2 +-
 src/src/WebServer/I2C_Scanner.cpp             |  2 +-
 src/src/WebServer/JSON.cpp                    |  8 +-
 src/src/WebServer/Log.cpp                     |  2 +-
 src/src/WebServer/PinStates.cpp               | 20 ++---
 src/src/WebServer/ToolsPage.cpp               |  2 +-
 src/src/WebServer/UploadPage.cpp              |  4 +-
 src/src/WebServer/WiFiScanner.cpp             |  8 +-
 43 files changed, 181 insertions(+), 166 deletions(-)

diff --git a/src/ESPEasy_common.h b/src/ESPEasy_common.h
index 3162022d37..faf8602d93 100644
--- a/src/ESPEasy_common.h
+++ b/src/ESPEasy_common.h
@@ -95,9 +95,6 @@ namespace std
    #include "user_interface.h"
   }
 
-  #ifdef FEATURE_MDNS
-    #include <ESP8266mDNS.h>
-  #endif
   #define SMALLEST_OTA_IMAGE 276848 // smallest known 2-step OTA image
   #define MAX_SKETCH_SIZE 1044464   // 1020 kB - 16 bytes
   #define PIN_D_MAX        16
@@ -117,9 +114,6 @@ namespace std
 //  #include  "esp32_ping.h"
   #include <rom/rtc.h>
   #include "esp_wifi.h" // Needed to call ESP-IDF functions like esp_wifi_....
-  #ifdef FEATURE_MDNS
-    #include <ESPmDNS.h>
-  #endif
   #define PIN_D_MAX        39
   #define MAX_SKETCH_SIZE 1900544   // 0x1d0000 look at partitions in csv file
 #endif
diff --git a/src/_C018.ino b/src/_C018.ino
index c2ee2aa852..3c2707ee7c 100644
--- a/src/_C018.ino
+++ b/src/_C018.ino
@@ -526,7 +526,7 @@ bool CPlugin_018(CPlugin::Function function, struct EventStruct *event, String&
         addHtml(c018_add_joinChanged_script_element_line(F("devaddr"), false));
         addHtml(c018_add_joinChanged_script_element_line(F("nskey"), false));
         addHtml(c018_add_joinChanged_script_element_line(F("appskey"), false));
-        addHtml("}");
+        addHtml('}');
         html_add_script_end();
       }
 
diff --git a/src/_N001_Email.ino b/src/_N001_Email.ino
index b830c42e04..170f11d454 100644
--- a/src/_N001_Email.ino
+++ b/src/_N001_Email.ino
@@ -110,10 +110,10 @@ boolean NPlugin_001_send(const NotificationSettingsStruct& notificationsettings,
 			mailheader.replace(String(F("$emailfrom")), notificationsettings.Sender);
 		} else {
 			String senderName = email_address.substring(0, pos_less);
-			senderName.replace("\"", ""); // Remove quotes
+			senderName.replace(F("\""), F("")); // Remove quotes
 			String address = email_address.substring(pos_less + 1);
-			address.replace("<", "");
-			address.replace(">", "");
+			address.replace(F("<"), F(""));
+			address.replace(F(">"), F(""));
 			address.trim();
 			senderName.trim();
 			mailheader.replace(String(F("$nodename")), senderName);
@@ -125,7 +125,7 @@ boolean NPlugin_001_send(const NotificationSettingsStruct& notificationsettings,
 		mailheader.replace(String(F("$ato")), notificationsettings.Receiver);
 		mailheader.replace(String(F("$subject")), aSub);
 		mailheader.replace(String(F("$espeasyversion")), String(BUILD));
-		aMesg.replace("\r", F("<br/>")); // re-write line breaks for Content-type: text/html
+		aMesg.replace(F("\r"), F("<br/>")); // re-write line breaks for Content-type: text/html
 
 		// Wait for Client to Start Sending
 		// The MTA Exchange
diff --git a/src/_P020_Ser2Net.ino b/src/_P020_Ser2Net.ino
index 46f2ab3894..d752a9f195 100644
--- a/src/_P020_Ser2Net.ino
+++ b/src/_P020_Ser2Net.ino
@@ -283,7 +283,7 @@ boolean Plugin_020(byte function, struct EventStruct *event, String& string)
         if (Settings.UseRules)
         {
           String message    = (char *)serial_buf;
-          int    NewLinePos = message.indexOf("\r\n");
+          int    NewLinePos = message.indexOf(F("\r\n"));
 
           if (NewLinePos > 0) {
             message = message.substring(0, NewLinePos);
diff --git a/src/_P022_PCA9685.ino b/src/_P022_PCA9685.ino
index 3f3b4f3749..8ff608bd6d 100644
--- a/src/_P022_PCA9685.ino
+++ b/src/_P022_PCA9685.ino
@@ -190,8 +190,8 @@ boolean Plugin_022(byte function, struct EventStruct *event, String& string)
       {
         LoadTaskSettings(event->TaskIndex);
         String name = line.substring(0, dotPos);
-        name.replace("[", "");
-        name.replace("]", "");
+        name.replace(F("["), F(""));
+        name.replace(F("]"), F(""));
 
         if (name.equalsIgnoreCase(getTaskDeviceName(event->TaskIndex))) {
           line            = line.substring(dotPos + 1);
diff --git a/src/_P026_Sysinfo.ino b/src/_P026_Sysinfo.ino
index ea9c5f11a1..e2db81a6d9 100644
--- a/src/_P026_Sysinfo.ino
+++ b/src/_P026_Sysinfo.ino
@@ -6,7 +6,9 @@
 
 
 #include "src/DataStructs/ESPEasy_packed_raw_data.h"
+#include "src/ESPEasyCore/ESPEasyNetwork.h"
 #include "src/Helpers/Memory.h"
+#include "ESPEasy-Globals.h"
 
 #define PLUGIN_026
 #define PLUGIN_ID_026         26
@@ -226,23 +228,11 @@ float P026_get_value(int type)
       break;
     }
     case 5:
-    {
-      value = NetworkLocalIP()[0];
-      break;
-    }
     case 6:
-    {
-      value = NetworkLocalIP()[1];
-      break;
-    }
     case 7:
-    {
-      value = NetworkLocalIP()[2];
-      break;
-    }
     case 8:
     {
-      value = NetworkLocalIP()[3];
+      value = NetworkLocalIP()[type - 5];
       break;
     }
     case 9:
diff --git a/src/_P042_Candle.ino b/src/_P042_Candle.ino
index b683921263..b3fc41e815 100644
--- a/src/_P042_Candle.ino
+++ b/src/_P042_Candle.ino
@@ -218,7 +218,7 @@ boolean Plugin_042(byte function, struct EventStruct *event, String& string)
         addHtml(F("    document.getElementById('web_RGB_Red').value = Math.round(picker.rgb[0]);"));
         addHtml(F("    document.getElementById('web_RGB_Green').value = Math.round(picker.rgb[1]);"));
         addHtml(F("    document.getElementById('web_RGB_Blue').value = Math.round(picker.rgb[2]);"));
-        addHtml("}");
+        addHtml('}');
         addHtml(F("</script>"));
 
         addHtml(F("<script type='text/javascript'>window.addEventListener('load', function(){"));
diff --git a/src/_P095_ILI9341.ino b/src/_P095_ILI9341.ino
index 02bffabe51..fa7a07478a 100644
--- a/src/_P095_ILI9341.ino
+++ b/src/_P095_ILI9341.ino
@@ -470,7 +470,7 @@ boolean Plugin_095(byte function, struct EventStruct *event, String& string)
             addLog(LOG_LEVEL_INFO, F("Fail to parse command correctly; please check API documentation"));
             String log2  = F("Parsed command = \"");
             log2 += string;
-            log2 += "\"";
+            log2 += F("\"");
             addLog(LOG_LEVEL_INFO, log2);
           }
         } 
diff --git a/src/src/Commands/InternalCommands.cpp b/src/src/Commands/InternalCommands.cpp
index b185d31c21..863f41c26c 100644
--- a/src/src/Commands/InternalCommands.cpp
+++ b/src/src/Commands/InternalCommands.cpp
@@ -48,6 +48,7 @@ bool checkNrArguments(const char *cmd, const char *Line, int nrArguments) {
 
   // 0 arguments means argument on pos1 is valid (the command) and argpos 2 should not be there.
   if (HasArgv(Line, nrArguments + 2)) {
+    #ifndef BUILD_NO_DEBUG
     if (loglevelActiveFor(LOG_LEVEL_ERROR)) {
       String log;
       log.reserve(128);
@@ -103,6 +104,7 @@ bool checkNrArguments(const char *cmd, const char *Line, int nrArguments) {
       log += F(" See: https://github.com/letscontrolit/ESPEasy/issues/2724");
       addLog(LOG_LEVEL_ERROR, log);
     }
+    #endif
 
     if (Settings.TolerantLastArgParse()) {
       return true;
@@ -286,7 +288,9 @@ bool executeInternalCommand(command_case_data & data)
     case 'n': {
       COMMAND_CASE_R(   "name", Command_Settings_Name,        1); // Settings.h
       COMMAND_CASE_R("nosleep", Command_System_NoSleep,       1); // System.h
+#ifdef USES_NOTIFIER
       COMMAND_CASE_R( "notify", Command_Notifications_Notify, 2); // Notifications.h
+#endif
       COMMAND_CASE_R("ntphost", Command_NTPHost,              1); // Time.h
       break;
     }
@@ -373,8 +377,10 @@ bool executeInternalCommand(command_case_data & data)
       break;
     }
     case 'w': {
+      #ifndef LIMIT_BUILD_SIZE
       COMMAND_CASE_R("wdconfig", Command_WD_Config, 3);               // WD.h
       COMMAND_CASE_R(  "wdread", Command_WD_Read,   2);               // WD.h
+      #endif
 
       if (data.cmd_lc[1] == 'i') {
         COMMAND_CASE_R(    "wifiapmode", Command_Wifi_APMode,     0); // WiFi.h
diff --git a/src/src/Commands/Notifications.cpp b/src/src/Commands/Notifications.cpp
index f1f98c535b..3a9355deab 100644
--- a/src/src/Commands/Notifications.cpp
+++ b/src/src/Commands/Notifications.cpp
@@ -1,5 +1,7 @@
 #include "../Commands/Notifications.h"
 
+#ifdef USES_NOTIFIER
+
 #include "../Commands/Common.h"
 
 #include "../../ESPEasy_common.h"
@@ -30,3 +32,5 @@ String Command_Notifications_Notify(struct EventStruct *event, const char* Line)
 	}
 	return return_command_success();
 }
+
+#endif
\ No newline at end of file
diff --git a/src/src/Commands/Notifications.h b/src/src/Commands/Notifications.h
index 8cb6c9379a..02357f39e6 100644
--- a/src/src/Commands/Notifications.h
+++ b/src/src/Commands/Notifications.h
@@ -1,8 +1,14 @@
 #ifndef COMMAND_NOTIFICATIONS_H
 #define COMMAND_NOTIFICATIONS_H
 
+#include "../../ESPEasy_common.h"
+
+#ifdef USES_NOTIFIER
+
 class String;
 
 String Command_Notifications_Notify(struct EventStruct *event, const char* Line);
 
+#endif
+
 #endif // COMMAND_NOTIFICATIONS_H
diff --git a/src/src/Commands/wd.cpp b/src/src/Commands/wd.cpp
index 72ec91afdb..8f9945109e 100644
--- a/src/src/Commands/wd.cpp
+++ b/src/src/Commands/wd.cpp
@@ -1,5 +1,6 @@
 #include "../Commands/wd.h"
 
+#ifndef LIMIT_BUILD_SIZE
 
 #include "../Commands/Common.h"
 
@@ -37,3 +38,5 @@ String Command_WD_Read(EventStruct *event, const char* Line)
   }
   return return_command_success();
 }
+
+#endif
\ No newline at end of file
diff --git a/src/src/Commands/wd.h b/src/src/Commands/wd.h
index 05feb63df2..4ef8ce014a 100644
--- a/src/src/Commands/wd.h
+++ b/src/src/Commands/wd.h
@@ -1,10 +1,16 @@
 #ifndef COMMAND_WD_H
 #define COMMAND_WD_H
 
+#include "../Commands/Common.h"
+
+#ifndef LIMIT_BUILD_SIZE
+
 class String;
 struct EventStruct;
 
 String Command_WD_Config(EventStruct *event, const char* Line);
 String Command_WD_Read(EventStruct *event, const char* Line);
 
+#endif
+
 #endif // COMMAND_WD_H
diff --git a/src/src/CustomBuild/define_plugin_sets.h b/src/src/CustomBuild/define_plugin_sets.h
index 59e5fa1580..5f71c84826 100644
--- a/src/src/CustomBuild/define_plugin_sets.h
+++ b/src/src/CustomBuild/define_plugin_sets.h
@@ -278,7 +278,7 @@ To create/register a plugin, you have to :
     #define USES_C008   // Generic HTTP
 //    #define USES_C009   // FHEM HTTP
 //    #define USES_C010   // Generic UDP
-    #define USES_C013   // ESPEasy P2P network
+//    #define USES_C013   // ESPEasy P2P network
 
 //    #define NOTIFIER_SET_STABLE
     #define NOTIFIER_SET_NONE
diff --git a/src/src/DataStructs/C013_p2p_dataStructs.cpp b/src/src/DataStructs/C013_p2p_dataStructs.cpp
index 724b5c8a8c..a13abd063f 100644
--- a/src/src/DataStructs/C013_p2p_dataStructs.cpp
+++ b/src/src/DataStructs/C013_p2p_dataStructs.cpp
@@ -3,6 +3,7 @@
 #include "../Globals/Plugins.h"
 #include "../../ESPEasy_common.h"
 
+#ifdef USES_C013
 
 C013_SensorInfoStruct::C013_SensorInfoStruct()
 {
@@ -44,3 +45,5 @@ bool C013_SensorDataStruct::isValid() const
   }
   return true;
 }
+
+#endif
\ No newline at end of file
diff --git a/src/src/DataStructs/C013_p2p_dataStructs.h b/src/src/DataStructs/C013_p2p_dataStructs.h
index f53be984ef..12b324d016 100644
--- a/src/src/DataStructs/C013_p2p_dataStructs.h
+++ b/src/src/DataStructs/C013_p2p_dataStructs.h
@@ -8,7 +8,7 @@
 
 // These structs are sent to other nodes, so make sure not to change order or offset in struct.
 
-
+#ifdef USES_C013
 struct C013_SensorInfoStruct
 {
   C013_SensorInfoStruct();
@@ -41,5 +41,6 @@ struct C013_SensorDataStruct
   float       Values[VARS_PER_TASK];
 };
 
+#endif
 
 #endif // DATASTRUCTS_C013_P2P_DATASTRUCTS_H
diff --git a/src/src/DataStructs/GpioFactorySettingsStruct.cpp b/src/src/DataStructs/GpioFactorySettingsStruct.cpp
index 25c37540c2..a5f5bf3690 100644
--- a/src/src/DataStructs/GpioFactorySettingsStruct.cpp
+++ b/src/src/DataStructs/GpioFactorySettingsStruct.cpp
@@ -1,4 +1,4 @@
-#include "GpioFactorySettingsStruct.h"
+#include "../DataStructs/GpioFactorySettingsStruct.h"
 
 #include "../CustomBuild/ESPEasyDefaults.h"
 
@@ -22,6 +22,7 @@ GpioFactorySettingsStruct::GpioFactorySettingsStruct(DeviceModel model)
   }
 
   switch (model) {
+#if defined(ESP8266) && !defined(LIMIT_BUILD_SIZE)
     case DeviceModel_Sonoff_Basic:
     case DeviceModel_Sonoff_TH1x:
     case DeviceModel_Sonoff_S2x:
@@ -88,6 +89,22 @@ GpioFactorySettingsStruct::GpioFactorySettingsStruct(DeviceModel model)
       i2c_sda    = -1;            // GPIO4 conflicts with relay control.
       i2c_scl    = -1;            // GPIO5 conflicts with SW input
       break;
+#else
+    case DeviceModel_Sonoff_Basic:
+    case DeviceModel_Sonoff_TH1x:
+    case DeviceModel_Sonoff_S2x:
+    case DeviceModel_Sonoff_TouchT1:
+    case DeviceModel_Sonoff_POWr2:
+    case DeviceModel_Sonoff_POW:
+    case DeviceModel_Sonoff_TouchT2:
+    case DeviceModel_Sonoff_TouchT3:
+    case DeviceModel_Sonoff_4ch:
+    case DeviceModel_Shelly1:
+    case DeviceModel_ShellyPLUG_S:
+      break;
+#endif
+
+
 #ifdef ESP32
     case DeviceMode_Olimex_ESP32_PoE:
       button[0]             = 34; // BUT1 Button
diff --git a/src/src/DataStructs/GpioFactorySettingsStruct.h b/src/src/DataStructs/GpioFactorySettingsStruct.h
index 08bc699f10..396642536d 100644
--- a/src/src/DataStructs/GpioFactorySettingsStruct.h
+++ b/src/src/DataStructs/GpioFactorySettingsStruct.h
@@ -6,6 +6,7 @@
 #include "../DataTypes/NetworkMedium.h"
 
 
+
 struct GpioFactorySettingsStruct {
   GpioFactorySettingsStruct(DeviceModel model = DeviceModel_default);
 
diff --git a/src/src/ESPEasyCore/ESPEasyNetwork.cpp b/src/src/ESPEasyCore/ESPEasyNetwork.cpp
index 0bb042e816..1ec0efee54 100644
--- a/src/src/ESPEasyCore/ESPEasyNetwork.cpp
+++ b/src/src/ESPEasyCore/ESPEasyNetwork.cpp
@@ -174,8 +174,8 @@ String NetworkCreateRFCCompliantHostname(bool force_add_unitnr) {
 String createRFCCompliantHostname(const String& oldString) {
   String result(oldString);
 
-  result.replace(" ", "-");
-  result.replace("_", "-"); // See RFC952
+  result.replace(' ', '-');
+  result.replace('_', '-'); // See RFC952
   return result;
 }
 
diff --git a/src/src/ESPEasyCore/ESPEasyRules.cpp b/src/src/ESPEasyCore/ESPEasyRules.cpp
index aba57c98fc..303f974c8f 100644
--- a/src/src/ESPEasyCore/ESPEasyRules.cpp
+++ b/src/src/ESPEasyCore/ESPEasyRules.cpp
@@ -178,7 +178,7 @@ void rulesProcessing(String& event) {
  \*********************************************************************************************/
 String rulesProcessingFile(const String& fileName, String& event) {
   if (!Settings.UseRules || !fileExists(fileName)) {
-    return "";
+    return F("");
   }
   #ifndef BUILD_NO_RAM_TRACKER
   checkRAM(F("rulesProcessingFile"));
@@ -260,7 +260,7 @@ String rulesProcessingFile(const String& fileName, String& event) {
           }
 
           // Prepare for new line
-          line = "";
+          line = F("");
           line.reserve(longestLineSize);
           firstNonSpaceRead = false;
           commentFound      = false;
@@ -282,7 +282,7 @@ String rulesProcessingFile(const String& fileName, String& event) {
           if (!commentFound) {
             line += '/';
 
-            if (line.endsWith("//")) {
+            if (line.endsWith(F("//"))) {
               // consider the rest of the line a comment
               commentFound = true;
             }
@@ -310,7 +310,7 @@ String rulesProcessingFile(const String& fileName, String& event) {
   #ifndef BUILD_NO_RAM_TRACKER
   checkRAM(F("rulesProcessingFile2"));
   #endif // ifndef BUILD_NO_RAM_TRACKER
-  return "";
+  return F("");
 }
 
 /********************************************************************************************\
@@ -429,63 +429,6 @@ bool get_next_argument(const String& fullCommand, int& index, String& argument,
   return argument.length() > 0;
 }
 
-/*  TD-er: Disabled for now, have to try and make the notation more intuitive.
-   bool parse_trigonometric_functions(const String& cmd_s_lower, const String& arg1, const String& arg2, double& result) {
- #ifdef USE_TRIGONOMETRIC_FUNCTIONS_RULES
-   if (cmd_s_lower.length() < 3) {
-    return false;
-   }
-   float farg1;
-   if (!validFloatFromString(arg1, farg1)) {
-    return false;
-   }
-   const bool angle_in_deg = cmd_s_lower.endsWith(F("_d"));
-   if (cmd_s_lower[0] == 'a') {
-    // acos, asin, atan, atan2
-    if (cmd_s_lower.startsWith(F("acos"))) {
-      result = acos(farg1);
-    } else if (cmd_s_lower.startsWith(F("asin"))) {
-      result = asin(farg1);
-    } else if (cmd_s_lower.startsWith(F("atan2"))) {
-      // Syntax like {atan:x:y} to give the angle with the X-axis given a coordinate in the XY-plane
-      float x = farg1;
-      float y;
-      if (validFloatFromString(arg2, y)) {
-        result = atan2(y, x); // Note the swapped order of y,x parameters
-      } else {
-        // No 2nd parameter
-        return false;
-      }
-    } else if (cmd_s_lower.startsWith(F("atan"))) {
-      result = atan(farg1);
-    } else {
-      return false;
-    }
-    if (angle_in_deg) {
-      farg1 = degrees(farg1);
-    }
-    return true;
-   }
-   // cos, sin, tan
-   // These functions have the angle as input, so convert the argument to radians first (if needed)
-   if (angle_in_deg) {
-    farg1 = radians(farg1);
-   }
-   if (cmd_s_lower.startsWith(F("cos"))) {
-    result = cos(farg1);
-   } else if (cmd_s_lower.startsWith(F("sin"))) {
-    result = sin(farg1);
-   } else if (cmd_s_lower.startsWith(F("tan"))) {
-    result = tan(farg1);
-   } else {
-    return false;
-   }
-   return true;
- #else
-   return false;
- #endif
-   }
- */
 bool parse_bitwise_functions(const String& cmd_s_lower, const String& arg1, const String& arg2, const String& arg3, int64_t& result) {
   if (loglevelActiveFor(LOG_LEVEL_INFO)) {
     String log = F("Bitwise: {");
@@ -619,8 +562,7 @@ void parse_string_commands(String& line) {
       double   fresult = 0.0;
       int64_t  iresult = 0;
 
-      if ( /*parse_trigonometric_functions(cmd_s_lower, arg1, arg2, fresult) ||*/
-        parse_math_functions(cmd_s_lower, arg1, arg2, arg3, fresult)) {
+      if (parse_math_functions(cmd_s_lower, arg1, arg2, arg3, fresult)) {
         const bool trimTrailingZeros = true;
         replacement = doubleToString(fresult, maxNrDecimals_double(fresult), trimTrailingZeros);
       } else if (parse_bitwise_functions(cmd_s_lower, arg1, arg2, arg3, iresult)) {
@@ -797,7 +739,7 @@ void parseCompleteNonCommentLine(String& line, String& event, String& log,
 
   String eventTrigger;
 
-  action = "";
+  action = F("");
 
   if (!codeBlock) // do not check "on" rules if a block of actions is to be
                   // processed
@@ -1008,8 +950,8 @@ bool ruleMatch(const String& event, const String& rule) {
   tmpRule.trim();
 
   // Ignore escape char
-  tmpRule.replace("[", "");
-  tmpRule.replace("]", "");
+  tmpRule.replace(F("["), F(""));
+  tmpRule.replace(F("]"), F(""));
 
   if (tmpEvent.equalsIgnoreCase(tmpRule)) {
     return true;
@@ -1182,28 +1124,28 @@ bool findCompareCondition(const String& check, char& compare, int& posStart, int
   int  comparePos = 0;
   bool found      = false;
 
-  if (((comparePos = check.indexOf("!=")) > 0) && (comparePos < posStart)) {
+  if (((comparePos = check.indexOf(F("!="))) > 0) && (comparePos < posStart)) {
     posStart = comparePos;
     posEnd   = posStart + 2;
     compare  = '<' + '>';
     found    = true;
   }
 
-  if (((comparePos = check.indexOf("<>")) > 0) && (comparePos < posStart)) {
+  if (((comparePos = check.indexOf(F("<>"))) > 0) && (comparePos < posStart)) {
     posStart = comparePos;
     posEnd   = posStart + 2;
     compare  = '<' + '>';
     found    = true;
   }
 
-  if (((comparePos = check.indexOf(">=")) > 0) && (comparePos < posStart)) {
+  if (((comparePos = check.indexOf(F(">="))) > 0) && (comparePos < posStart)) {
     posStart = comparePos;
     posEnd   = posStart + 2;
     compare  = '>' + '=';
     found    = true;
   }
 
-  if (((comparePos = check.indexOf("<=")) > 0) && (comparePos < posStart)) {
+  if (((comparePos = check.indexOf(F("<="))) > 0) && (comparePos < posStart)) {
     posStart = comparePos;
     posEnd   = posStart + 2;
     compare  = '<' + '=';
diff --git a/src/src/ESPEasyCore/ESPEasyRules.h b/src/src/ESPEasyCore/ESPEasyRules.h
index e9bcc56451..6adff71001 100644
--- a/src/src/ESPEasyCore/ESPEasyRules.h
+++ b/src/src/ESPEasyCore/ESPEasyRules.h
@@ -71,7 +71,6 @@ bool get_next_argument(const String& fullCommand,
                        String      & argument,
                        char          separator);
 
-// bool parse_trigonometric_functions(const String& cmd_s_lower, const String& arg1, const String& arg2, double& result);
 bool parse_bitwise_functions(const String& cmd_s_lower,
                              const String& arg1,
                              const String& arg2,
diff --git a/src/src/ESPEasyCore/ESPEasyWifi.cpp b/src/src/ESPEasyCore/ESPEasyWifi.cpp
index 7e9657f351..c143ed8844 100644
--- a/src/src/ESPEasyCore/ESPEasyWifi.cpp
+++ b/src/src/ESPEasyCore/ESPEasyWifi.cpp
@@ -13,6 +13,7 @@
 #include "../Globals/NetworkState.h"
 #include "../Globals/RTC.h"
 #include "../Globals/SecuritySettings.h"
+#include "../Globals/Services.h"
 #include "../Globals/Settings.h"
 #include "../Helpers/ESPEasy_time_calc.h"
 #include "../Helpers/Networking.h"
@@ -798,6 +799,9 @@ String formatScanResult(int i, const String& separator, int32_t& rssi) {
 
 #ifndef ESP32
 String SDKwifiStatusToString(uint8_t sdk_wifistatus) {
+  #ifdef LIMIT_BUILD_SIZE
+  return String(sdk_wifistatus);
+  #else
   switch (sdk_wifistatus) {
     case STATION_IDLE:           return F("STATION_IDLE");
     case STATION_CONNECTING:     return F("STATION_CONNECTING");
@@ -807,11 +811,15 @@ String SDKwifiStatusToString(uint8_t sdk_wifistatus) {
     case STATION_GOT_IP:         return F("STATION_GOT_IP");
   }
   return getUnknownString();
+  #endif
 }
 
 #endif // ifndef ESP32
 
 String ArduinoWifiStatusToString(uint8_t arduino_corelib_wifistatus) {
+  #ifdef LIMIT_BUILD_SIZE
+  return String(arduino_corelib_wifistatus);
+  #else
   String log;
 
   switch (arduino_corelib_wifistatus) {
@@ -826,6 +834,7 @@ String ArduinoWifiStatusToString(uint8_t arduino_corelib_wifistatus) {
     default:  log                += arduino_corelib_wifistatus; break;
   }
   return log;
+  #endif
 }
 
 String ESPeasyWifiStatusToString() {
@@ -847,7 +856,8 @@ String ESPeasyWifiStatusToString() {
 }
 
 void logConnectionStatus() {
-  #ifdef esp8266
+#ifndef BUILD_NO_DEBUG
+  #ifdef ESP8266
   const uint8_t arduino_corelib_wifistatus = WiFi.status();
   const uint8_t sdk_wifistatus             = wifi_station_get_connect_status();
 
@@ -861,7 +871,6 @@ void logConnectionStatus() {
     }
   }
   #endif
-#ifndef BUILD_NO_DEBUG
 
   if (loglevelActiveFor(LOG_LEVEL_INFO)) {
     String log = F("WIFI  : Arduino wifi status: ");
diff --git a/src/src/ESPEasyCore/ESPEasyWifi_ProcessEvent.cpp b/src/src/ESPEasyCore/ESPEasyWifi_ProcessEvent.cpp
index fae5701243..1c165e7356 100644
--- a/src/src/ESPEasyCore/ESPEasyWifi_ProcessEvent.cpp
+++ b/src/src/ESPEasyCore/ESPEasyWifi_ProcessEvent.cpp
@@ -232,10 +232,8 @@ void processGotIP() {
 
   IPAddress ip = NetworkLocalIP();
 
-  if (!useStaticIP()) {
-    if ((ip[0] == 0) && (ip[1] == 0) && (ip[2] == 0) && (ip[3] == 0)) {
-      return;
-    }
+  if (!useStaticIP() && !ip.isSet()) {
+    return;
   }
   const IPAddress gw       = NetworkGatewayIP();
   const IPAddress subnet   = NetworkSubnetMask();
diff --git a/src/src/Globals/Plugins.cpp b/src/src/Globals/Plugins.cpp
index de78f6028e..26b8b56a4d 100644
--- a/src/src/Globals/Plugins.cpp
+++ b/src/src/Globals/Plugins.cpp
@@ -403,15 +403,15 @@ bool PluginCall(byte Function, struct EventStruct *event, String& str)
       taskIndex_t firstTask = 0;
       taskIndex_t lastTask = TASKS_MAX;
       String command = String(str);                           // Local copy to avoid warning in ExecuteCommand
-      int dotPos = command.indexOf(".");                      // Find first period
+      int dotPos = command.indexOf('.');                      // Find first period
       if (Function == PLUGIN_WRITE                            // Only applicable on PLUGIN_WRITE function
         && dotPos > -1) {                                     // First precondition is just a quick check for a period (fail-fast strategy)
         String arg0 = parseString(command, 1);                // Get first argument
-        dotPos = arg0.indexOf(".");
+        dotPos = arg0.indexOf('.');
         if (dotPos > -1) {
           String thisTaskName = command.substring(0, dotPos); // Extract taskname prefix
-          thisTaskName.replace("[", "");                      // Remove the optional square brackets
-          thisTaskName.replace("]", "");
+          thisTaskName.replace(F("["), F(""));                      // Remove the optional square brackets
+          thisTaskName.replace(F("]"), F(""));
           if (thisTaskName.length() > 0) {                    // Second precondition
             taskIndex_t thisTask = findTaskIndexByName(thisTaskName);
             if (!validTaskIndex(thisTask)) {                  // Taskname not found or invalid, check for a task number?
diff --git a/src/src/Globals/Services.h b/src/src/Globals/Services.h
index 483fb5bc6b..d876cb7aeb 100644
--- a/src/src/Globals/Services.h
+++ b/src/src/Globals/Services.h
@@ -5,18 +5,22 @@
 
 #ifdef FEATURE_ARDUINO_OTA
   #include <ArduinoOTA.h>
-  #ifdef FEATURE_MDNS
-    #ifdef ESP8266
-      #include <ESP8266mDNS.h>
-    #endif
-    #ifdef ESP32
-      #include <ESPmDNS.h>
-    #endif
-  #endif
 
   extern bool ArduinoOTAtriggered;
+
+  #ifndef FEATURE_MDNS
+    #define FEATURE_MDNS
+  #endif
 #endif
 
+#ifdef FEATURE_MDNS
+  #ifdef ESP8266
+    #include <ESP8266mDNS.h>
+  #endif
+  #ifdef ESP32
+    #include <ESPmDNS.h>
+  #endif
+#endif
 
 #ifdef ESP8266
 
diff --git a/src/src/Helpers/ESPEasy_FactoryDefault.cpp b/src/src/Helpers/ESPEasy_FactoryDefault.cpp
index 3e5e05bd57..4d624f5280 100644
--- a/src/src/Helpers/ESPEasy_FactoryDefault.cpp
+++ b/src/src/Helpers/ESPEasy_FactoryDefault.cpp
@@ -220,8 +220,10 @@ void ResetFactory()
   strcpy_P(Settings.Name, PSTR(PLUGIN_DESCR));
 #endif // ifdef PLUGIN_DESCR
 
+#ifndef LIMIT_BUILD_SIZE
   addPredefinedPlugins(gpio_settings);
   addPredefinedRules(gpio_settings);
+#endif
 
 #if DEFAULT_CONTROLLER
   {
diff --git a/src/src/Helpers/ESPEasy_checks.cpp b/src/src/Helpers/ESPEasy_checks.cpp
index 697dd4e68d..dad5f2c90a 100644
--- a/src/src/Helpers/ESPEasy_checks.cpp
+++ b/src/src/Helpers/ESPEasy_checks.cpp
@@ -3,7 +3,6 @@
 
 #include "../../ESPEasy_common.h"
 
-#include "../DataStructs/C013_p2p_dataStructs.h"
 #include "../DataStructs/CRCStruct.h"
 #include "../DataStructs/ControllerSettingsStruct.h"
 #include "../DataStructs/DeviceStruct.h"
@@ -15,7 +14,6 @@
 #include "../DataStructs/LogStruct.h"
 #include "../DataStructs/NodeStruct.h"
 #include "../DataStructs/NodeStruct.h"
-#include "../DataStructs/NotificationSettingsStruct.h"
 #include "../DataStructs/PortStatusStruct.h"
 #include "../DataStructs/ProtocolStruct.h"
 #include "../DataStructs/RTCStruct.h"
@@ -30,9 +28,13 @@
 
 #include <cstddef>
 
+#ifdef USES_C013
+#include "../DataStructs/C013_p2p_dataStructs.h"
+#endif
 
 #ifdef USES_NOTIFIER
 #include "../DataStructs/NotificationStruct.h"
+#include "../DataStructs/NotificationSettingsStruct.h"
 #endif
 
 
@@ -93,8 +95,10 @@ void run_compiletime_checks() {
   check_size<portStatusStruct,                      6u>();
   check_size<ResetFactoryDefaultPreference_struct,  4u>();
   check_size<GpioFactorySettingsStruct,             18u>();
+  #ifdef USES_C013
   check_size<C013_SensorInfoStruct,                 137u>();
   check_size<C013_SensorDataStruct,                 24u>();
+  #endif
   #if defined(USE_NON_STANDARD_24_TASKS) && defined(ESP8266)
     static_assert(TASKS_MAX == 24, "TASKS_MAX invalid size");
   #endif
diff --git a/src/src/Helpers/Hardware.cpp b/src/src/Helpers/Hardware.cpp
index f9a83d5ddd..daed248de6 100644
--- a/src/src/Helpers/Hardware.cpp
+++ b/src/src/Helpers/Hardware.cpp
@@ -564,6 +564,7 @@ String getDeviceModelString(DeviceModel model) {
   result = getDeviceModelBrandString(model);
 
   switch (model) {
+#if defined(ESP8266) && !defined(LIMIT_BUILD_SIZE)
     case DeviceModel_Sonoff_Basic:   result      += F(" Basic");   break;
     case DeviceModel_Sonoff_TH1x:    result      += F(" TH1x");    break;
     case DeviceModel_Sonoff_S2x:     result      += F(" S2x");     break;
@@ -575,15 +576,29 @@ String getDeviceModelString(DeviceModel model) {
     case DeviceModel_Sonoff_POWr2:   result      += F(" POW-r2");  break;
     case DeviceModel_Shelly1:        result      += '1';           break;
     case DeviceModel_ShellyPLUG_S:   result      += F(" PLUG S");  break;
-    #ifdef ESP32
+#else
+    case DeviceModel_Sonoff_Basic:
+    case DeviceModel_Sonoff_TH1x:
+    case DeviceModel_Sonoff_S2x:
+    case DeviceModel_Sonoff_TouchT1:
+    case DeviceModel_Sonoff_TouchT2:
+    case DeviceModel_Sonoff_TouchT3:
+    case DeviceModel_Sonoff_4ch:
+    case DeviceModel_Sonoff_POW:
+    case DeviceModel_Sonoff_POWr2:
+    case DeviceModel_Shelly1:
+    case DeviceModel_ShellyPLUG_S:
+      result += F("default");  break;
+#endif
+#ifdef ESP32
     case DeviceMode_Olimex_ESP32_PoE: result     += F(" ESP32-PoE"); break;
     case DeviceMode_Olimex_ESP32_EVB: result     += F(" ESP32-EVB"); break;
     case DeviceMode_Olimex_ESP32_GATEWAY: result += F(" ESP32-GATEWAY"); break;
-    #else
+#else
     case DeviceMode_Olimex_ESP32_PoE:
     case DeviceMode_Olimex_ESP32_EVB:
     case DeviceMode_Olimex_ESP32_GATEWAY:
-    #endif
+#endif
 
     case DeviceModel_default:
     case DeviceModel_MAX:            result += F("default");  break;
diff --git a/src/src/Helpers/MDNS_Helper.cpp b/src/src/Helpers/MDNS_Helper.cpp
index d9154b8130..12aa2daf01 100644
--- a/src/src/Helpers/MDNS_Helper.cpp
+++ b/src/src/Helpers/MDNS_Helper.cpp
@@ -1,10 +1,11 @@
-#include "MDNS_Helper.h"
+#include "../Helpers/MDNS_Helper.h"
 
 #include "../ESPEasyCore/ESPEasy_Log.h"
 #include "../ESPEasyCore/ESPEasyEth.h"
 #include "../ESPEasyCore/ESPEasyNetwork.h"
 
 #include "../Globals/NetworkState.h"
+#include "../Globals/Services.h"
 #include "../Globals/Settings.h"
 
 #include "../Helpers/StringProvider.h"
diff --git a/src/src/Helpers/StringConverter.cpp b/src/src/Helpers/StringConverter.cpp
index 0d4ad5cfeb..25fdaad1a3 100644
--- a/src/src/Helpers/StringConverter.cpp
+++ b/src/src/Helpers/StringConverter.cpp
@@ -368,7 +368,7 @@ String to_json_object_value(const String& object, const String& value) {
   String result;
 
   result.reserve(object.length() + value.length() + 6);
-  wrap_String(object, "\"", result);
+  wrap_String(object, F("\""), result);
   result += F(":");
 
   if (value.length() == 0) {
@@ -387,9 +387,9 @@ String to_json_object_value(const String& object, const String& value) {
       tmpValue.replace('\n', '^');
       tmpValue.replace('\r', '^');
       tmpValue.replace('"',  '\'');
-      wrap_String(tmpValue, "\"", result);
+      wrap_String(tmpValue, F("\""), result);
     } else {
-      wrap_String(value, "\"", result);
+      wrap_String(value, F("\""), result);
     }
   } else {
     // It is a numerical
@@ -738,6 +738,7 @@ void parseSingleControllerVariable(String            & s,
   }
 }
 
+// FIXME TD-er: These macros really increase build size.
 // Simple macro to create the replacement string only when needed.
 #define SMART_REPL(T, S) \
   if (s.indexOf(T) != -1) { repl((T), (S), s, useURLencode); }
@@ -842,6 +843,9 @@ bool getConvertArgumentString(const String& marker, const String& s, String& arg
   return true;
 }
 
+
+// FIXME TD-er: These macros really increase build size
+
 // Parse conversions marked with "%conv_marker%(float)"
 // Must be called last, since all sensor values must be converted, processed, etc.
 void parseStandardConversions(String& s, boolean useURLencode) {
diff --git a/src/src/Helpers/StringGenerator_GPIO.cpp b/src/src/Helpers/StringGenerator_GPIO.cpp
index a58eab0ab5..4e1e52152b 100644
--- a/src/src/Helpers/StringGenerator_GPIO.cpp
+++ b/src/src/Helpers/StringGenerator_GPIO.cpp
@@ -99,8 +99,8 @@ String formatGpioName_ADC(int gpio_pin) {
       return F("Hall Effect");
     }
     String res = F("ADC# ch?");
-    res.replace("#", String(adc));
-    res.replace("?", String(ch));
+    res.replace(F("#"), String(adc));
+    res.replace(F("?"), String(ch));
 
     if (t >= 0) {
       res += F(" (T");
diff --git a/src/src/Helpers/SystemVariables.cpp b/src/src/Helpers/SystemVariables.cpp
index 20b4d3e14a..ba1a5f0f21 100644
--- a/src/src/Helpers/SystemVariables.cpp
+++ b/src/src/Helpers/SystemVariables.cpp
@@ -193,12 +193,12 @@ void SystemVariables::parseSystemVariables(String& s, boolean useURLencode)
   }
   while (enumval != SystemVariables::Enum::UNKNOWN);
 
-  const int v_index = s.indexOf("%v");
+  const int v_index = s.indexOf(F("%v"));
 
   if ((v_index != -1)) {
     unsigned int i;
     if (validUIntFromString(s.substring(v_index + 2), i)) {
-      String key = "%v" + String(i) + '%';
+      const String key = String(F("%v")) + String(i) + '%';
       if (s.indexOf(key) != -1) {
         const bool trimTrailingZeros = true;
         const String value = doubleToString(getCustomFloatVar(i), 6, trimTrailingZeros);
diff --git a/src/src/Helpers/_CPlugin_Helper_webform.cpp b/src/src/Helpers/_CPlugin_Helper_webform.cpp
index 7c4ccd0290..c74ad5f5b0 100644
--- a/src/src/Helpers/_CPlugin_Helper_webform.cpp
+++ b/src/src/Helpers/_CPlugin_Helper_webform.cpp
@@ -75,7 +75,7 @@ String getControllerParameterName(protocolIndex_t                   ProtocolInde
   if (!displayName) {
     // Change name to lower case and remove spaces to make it an internal name.
     name.toLowerCase();
-    name.replace(" ", "");
+    name.replace(F(" "), F(""));
   }
   return name;
 }
diff --git a/src/src/WebServer/AdvancedConfigPage.cpp b/src/src/WebServer/AdvancedConfigPage.cpp
index 548c28b71b..1c8216126f 100644
--- a/src/src/WebServer/AdvancedConfigPage.cpp
+++ b/src/src/WebServer/AdvancedConfigPage.cpp
@@ -234,7 +234,8 @@ void addFormDstSelect(bool isStart, uint16_t choice) {
   }
   TimeChangeRule rule(isStart ? tmpstart : tmpend, 0);
   {
-    String weeklabel = isStart ? F("Start (week, dow, month)")  : F("End (week, dow, month)");
+    String weeklabel = isStart ? F("Start")  : F("End");
+    weeklabel += F(" (week, dow, month)");
     String weekid  = isStart ? F("dststartweek")  : F("dstendweek");
     String week[5]       = { F("Last"), F("1st"), F("2nd"), F("3rd"), F("4th") };
     int    weekValues[5] = { 0, 1, 2, 3, 4 };
diff --git a/src/src/WebServer/FactoryResetPage.cpp b/src/src/WebServer/FactoryResetPage.cpp
index 58ed6c816c..56de87c747 100644
--- a/src/src/WebServer/FactoryResetPage.cpp
+++ b/src/src/WebServer/FactoryResetPage.cpp
@@ -34,6 +34,7 @@ void handle_factoryreset() {
   html_TR();
   addFormHeader(F("Factory Reset"));
 
+#ifndef LIMIT_BUILD_SIZE
   if (web_server.hasArg("fdm")) {
     DeviceModel model = static_cast<DeviceModel>(getFormItemInt("fdm"));
 
@@ -42,6 +43,7 @@ void handle_factoryreset() {
     }
   }
 
+
   if (web_server.hasArg(F("savepref"))) {
     // User choose a pre-defined config and wants to save it as the new default.
     ResetFactoryDefaultPreference.keepUnitName(isFormItemChecked("kun"));
@@ -52,6 +54,7 @@ void handle_factoryreset() {
     applyFactoryDefaultPref();
     addHtmlError(SaveSettings());
   }
+#endif
 
   if (web_server.hasArg(F("performfactoryreset"))) {
     // User confirmed to really perform the reset.
@@ -60,6 +63,7 @@ void handle_factoryreset() {
     // No need to call SaveSettings(); ResetFactory() will save the new settings.
     ResetFactory();
   } else {
+    #ifndef LIMIT_BUILD_SIZE
     // Nothing chosen yet, show options.
     addTableSeparator(F("Settings to keep"), 2, 3);
 
@@ -86,7 +90,7 @@ void handle_factoryreset() {
     html_TR_TD();
     html_TD();
     addSubmitButton(F("Save Preferences"), F("savepref"));
-
+    #endif
 
     html_TR_TD_height(30);
 
@@ -128,8 +132,8 @@ void addPreDefinedConfigSelector() {
 void handle_factoryreset_json() {
   if (!isLoggedIn()) { return; }
   TXBuffer.startJsonStream();
-  addHtml("{");
-
+  addHtml('{');
+#ifndef LIMIT_BUILD_SIZE
   if (web_server.hasArg("fdm")) {
     DeviceModel model = static_cast<DeviceModel>(getFormItemInt("fdm"));
 
@@ -157,6 +161,7 @@ void handle_factoryreset_json() {
   if (web_server.hasArg("klog")) {
     ResetFactoryDefaultPreference.keepLogSettings(isFormItemChecked("klog"));
   }
+#endif
   String error;
   bool   performReset = false;
   bool   savePref     = false;
@@ -184,7 +189,7 @@ void handle_factoryreset_json() {
   }
 
   stream_last_json_object_value(F("status"), error);
-  addHtml("}");
+  addHtml('}');
   TXBuffer.endStream();
 
   if (performReset) {
diff --git a/src/src/WebServer/FileList.cpp b/src/src/WebServer/FileList.cpp
index c44abdb651..3b1a31d0b5 100644
--- a/src/src/WebServer/FileList.cpp
+++ b/src/src/WebServer/FileList.cpp
@@ -120,7 +120,7 @@ void handle_filelist_json() {
   }
 
   if (firstentry) {
-    addHtml("}");
+    addHtml('}');
   }
 
   # endif // if defined(ESP8266)
diff --git a/src/src/WebServer/I2C_Scanner.cpp b/src/src/WebServer/I2C_Scanner.cpp
index 1cbcaf0e00..d5a68693d6 100644
--- a/src/src/WebServer/I2C_Scanner.cpp
+++ b/src/src/WebServer/I2C_Scanner.cpp
@@ -296,7 +296,7 @@ int scanI2CbusForDevices( // Utility function for scanning the I2C bus for valid
         String description = getKnownI2Cdevice(address);
 
         if (description.length() > 0) {
-          description.replace(",", "<BR>");
+          description.replace(F(","), F("<BR>"));
           addHtml(description);
         }
         nDevices++;
diff --git a/src/src/WebServer/JSON.cpp b/src/src/WebServer/JSON.cpp
index 37098c39df..4fd0333142 100644
--- a/src/src/WebServer/JSON.cpp
+++ b/src/src/WebServer/JSON.cpp
@@ -134,7 +134,7 @@ void handle_json()
 
   if (!showSpecificTask)
   {
-    addHtml("{");
+    addHtml('{');
 
     if (showSystem) {
       addHtml(F("\"System\":{\n"));
@@ -228,7 +228,7 @@ void handle_json()
             addHtml(F("\"nodes\":[\n")); // open json array if >0 nodes
           }
 
-          addHtml("{");
+          addHtml('{');
           stream_next_json_object_value(F("nr"), String(it->first));
           stream_next_json_object_value(F("name"),
                                         (it->first != Settings.Unit) ? it->second.nodeName : Settings.Name);
@@ -304,7 +304,7 @@ void handle_json()
 
         for (byte x = 0; x < valueCount; x++)
         {
-          addHtml("{");
+          addHtml('{');
           stream_next_json_object_value(F("ValueNumber"), String(x + 1));
           stream_next_json_object_value(F("Name"),        String(ExtraTaskSettings.TaskDeviceValueNames[x]));
           stream_next_json_object_value(F("NrDecimals"),  String(ExtraTaskSettings.TaskDeviceValueDecimals[x]));
@@ -326,7 +326,7 @@ void handle_json()
 
         for (controllerIndex_t x = 0; x < CONTROLLER_MAX; x++)
         {
-          addHtml("{");
+          addHtml('{');
           stream_next_json_object_value(F("Controller"), String(x + 1));
           stream_next_json_object_value(F("IDX"),        String(Settings.TaskDeviceID[x][TaskIndex]));
           stream_last_json_object_value(F("Enabled"), jsonBool(Settings.TaskDeviceSendData[x][TaskIndex]));
diff --git a/src/src/WebServer/Log.cpp b/src/src/WebServer/Log.cpp
index 25c162bbf7..330d8f3ffc 100644
--- a/src/src/WebServer/Log.cpp
+++ b/src/src/WebServer/Log.cpp
@@ -59,7 +59,7 @@ void handle_log_JSON() {
       if (i != 0) {
         addHtml(",");
       }
-      addHtml("{");
+      addHtml('{');
       int loglevel;
       stream_next_json_object_value(F("label"), getLogLevelDisplayStringFromIndex(i, loglevel));
       stream_last_json_object_value(F("loglevel"), String(loglevel));
diff --git a/src/src/WebServer/PinStates.cpp b/src/src/WebServer/PinStates.cpp
index 8dced5ae24..8727aff364 100644
--- a/src/src/WebServer/PinStates.cpp
+++ b/src/src/WebServer/PinStates.cpp
@@ -23,16 +23,16 @@ void handle_pinstates_json() {
   TXBuffer.startJsonStream();
 
   bool first = true;
-  addHtml(F("["));
+  addHtml('[');
 
   for (std::map<uint32_t, portStatusStruct>::iterator it = globalMapPortStatus.begin(); it != globalMapPortStatus.end(); ++it)
   {
     if (!first) {
-      addHtml(",");
+      addHtml(',');
     } else {
       first = false;
     }
-    addHtml("{");
+    addHtml('{');
 
 
     const uint16_t plugin = getPluginFromKey(it->first);
@@ -47,7 +47,7 @@ void handle_pinstates_json() {
     stream_last_json_object_value(F("init"), String(it->second.init));
   }
 
-  addHtml(F("]"));
+  addHtml(']');
 
   TXBuffer.endStream();
 }
@@ -71,29 +71,29 @@ void handle_pinstates() {
   html_table_class_multirow();
   html_TR();
   html_table_header(F("Plugin"), F("Official_plugin_list"), 0);
-  html_table_header("GPIO");
-  html_table_header("Mode");
+  html_table_header(F("GPIO"));
+  html_table_header(F("Mode"));
   html_table_header(F("Value/State"));
   html_table_header(F("Task"));
   html_table_header(F("Monitor"));
   html_table_header(F("Command"));
-  html_table_header("Init");
+  html_table_header(F("Init"));
 
   for (std::map<uint32_t, portStatusStruct>::iterator it = globalMapPortStatus.begin(); it != globalMapPortStatus.end(); ++it)
   {
     html_TR_TD();
-    addHtml("P");
+    addHtml('P');
     const uint16_t plugin = getPluginFromKey(it->first);
     const uint16_t port   = getPortFromKey(it->first);
 
     if (plugin < 100)
     {
-      addHtml("0");
+      addHtml('0');
     }
 
     if (plugin < 10)
     {
-      addHtml("0");
+      addHtml('0');
     }
     addHtmlInt(plugin);
     html_TD();
diff --git a/src/src/WebServer/ToolsPage.cpp b/src/src/WebServer/ToolsPage.cpp
index e47954b8ee..bbeba32654 100644
--- a/src/src/WebServer/ToolsPage.cpp
+++ b/src/src/WebServer/ToolsPage.cpp
@@ -134,7 +134,7 @@ void handle_tools() {
       bool     otaEnabled = OTA_possible(maxSketchSize, use2step);
       addFormSubHeader(F("Firmware"));
       html_TR_TD_height(30);
-      addWideButton(F("update"), F("Update Firmware"), "", otaEnabled);
+      addWideButton(F("update"), F("Update Firmware"), F(""), otaEnabled);
       addHelpButton(F("EasyOTA"));
       html_TD();
       addHtml(F("Load a new firmware"));
diff --git a/src/src/WebServer/UploadPage.cpp b/src/src/WebServer/UploadPage.cpp
index 7e2993d8f7..ad03c577c0 100644
--- a/src/src/WebServer/UploadPage.cpp
+++ b/src/src/WebServer/UploadPage.cpp
@@ -78,9 +78,9 @@ void handle_upload_json() {
   if (!isLoggedIn()) { result = 255; }
 
   TXBuffer.startJsonStream();
-  addHtml("{");
+  addHtml('{');
   stream_next_json_object_value(F("status"), String(result));
-  addHtml("}");
+  addHtml('}');
 
   TXBuffer.endStream();
 }
diff --git a/src/src/WebServer/WiFiScanner.cpp b/src/src/WebServer/WiFiScanner.cpp
index 73453b07fe..b527943479 100644
--- a/src/src/WebServer/WiFiScanner.cpp
+++ b/src/src/WebServer/WiFiScanner.cpp
@@ -20,14 +20,14 @@ void handle_wifiscanner_json() {
   if (!isLoggedIn()) { return; }
   navMenuIndex = MENU_INDEX_TOOLS;
   TXBuffer.startJsonStream();
-  addHtml("[{");
+  addHtml(F("[{"));
   bool firstentry = true;
   int  n          = WiFi.scanNetworks(false, true);
 
   for (int i = 0; i < n; ++i)
   {
     if (firstentry) { firstentry = false; }
-    else { addHtml(",{"); }
+    else { addHtml(F(",{")); }
     String authType;
 
     switch (WiFi.encryptionType(i)) {
@@ -58,9 +58,9 @@ void handle_wifiscanner_json() {
     stream_last_json_object_value(getLabel(LabelType::WIFI_RSSI), String(WiFi.RSSI(i)));
   }
   if (firstentry) {
-    addHtml("}");
+    addHtml('}');
   }
-  addHtml("]");
+  addHtml(']');
   TXBuffer.endStream();
 }