diff --git a/code/espurna/button.ino b/code/espurna/button.ino
index ea550e1f..4d8afef5 100644
--- a/code/espurna/button.ino
+++ b/code/espurna/button.ino
@@ -10,6 +10,8 @@ Copyright (C) 2016-2018 by Xose Pérez <xose dot perez at gmail dot com>
 // BUTTON
 // -----------------------------------------------------------------------------
 
+#if BUTTON_SUPPORT
+
 #include <DebounceEvent.h>
 #include <vector>
 
@@ -266,3 +268,5 @@ void buttonLoop() {
     #endif
 
 }
+
+#endif // BUTTON_SUPPORT
diff --git a/code/espurna/config/general.h b/code/espurna/config/general.h
index 395025bf..32e75298 100644
--- a/code/espurna/config/general.h
+++ b/code/espurna/config/general.h
@@ -201,6 +201,10 @@
 // BUTTON
 //------------------------------------------------------------------------------
 
+#ifndef BUTTON_SUPPORT
+#define BUTTON_SUPPORT              1
+#endif
+
 #ifndef BUTTON_DEBOUNCE_DELAY
 #define BUTTON_DEBOUNCE_DELAY       50          // Debounce delay (ms)
 #endif
@@ -217,6 +221,14 @@
 #define BUTTON_LNGLNGCLICK_DELAY    10000       // Time in ms holding the button down to get a long-long click
 #endif
 
+//------------------------------------------------------------------------------
+// LED
+//------------------------------------------------------------------------------
+
+#ifndef LED_SUPPORT
+#define LED_SUPPORT                 1
+#endif
+
 //------------------------------------------------------------------------------
 // RELAY
 //------------------------------------------------------------------------------
diff --git a/code/espurna/config/hardware.h b/code/espurna/config/hardware.h
index 62050eca..9a0226ff 100644
--- a/code/espurna/config/hardware.h
+++ b/code/espurna/config/hardware.h
@@ -37,9 +37,11 @@
     // Disable non-core modules
     #define ALEXA_SUPPORT           0
     #define BROKER_SUPPORT          0
+    #define BUTTON_SUPPORT          0
     #define DOMOTICZ_SUPPORT        0
     #define HOMEASSISTANT_SUPPORT   0
     #define I2C_SUPPORT             0
+    #define MDNS_SERVER_SUPPORT     0
     #define MQTT_SUPPORT            0
     #define NTP_SUPPORT             0
     #define SCHEDULER_SUPPORT       0
@@ -47,6 +49,14 @@
     #define THINGSPEAK_SUPPORT      0
     #define WEB_SUPPORT             0
 
+    // Extra light-weight image
+    //#define DEBUG_SERIAL_SUPPORT    0
+    //#define DEBUG_TELNET_SUPPORT    0
+    //#define DEBUG_WEB_SUPPORT       0
+    //#define LED_SUPPORT             0
+    //#define TELNET_SUPPORT          0
+    //#define TERMINAL_SUPPORT        0
+
 // -----------------------------------------------------------------------------
 // Development boards
 // -----------------------------------------------------------------------------
diff --git a/code/espurna/espurna.ino b/code/espurna/espurna.ino
index 5673fd03..adc77fcf 100644
--- a/code/espurna/espurna.ino
+++ b/code/espurna/espurna.ino
@@ -99,8 +99,12 @@ void setup() {
     #endif
 
     relaySetup();
-    buttonSetup();
-    ledSetup();
+    #if BUTTON_SUPPORT
+        buttonSetup();
+    #endif
+    #if LED_SUPPORT
+        ledSetup();
+    #endif
     #if MQTT_SUPPORT
         mqttSetup();
     #endif
diff --git a/code/espurna/led.ino b/code/espurna/led.ino
index 06fac792..f71aa31b 100644
--- a/code/espurna/led.ino
+++ b/code/espurna/led.ino
@@ -10,6 +10,8 @@ Copyright (C) 2016-2018 by Xose Pérez <xose dot perez at gmail dot com>
 // LED
 // -----------------------------------------------------------------------------
 
+#if LED_SUPPORT
+
 typedef struct {
     unsigned char pin;
     bool reverse;
@@ -290,3 +292,5 @@ void ledLoop() {
     _led_update = false;
 
 }
+
+#endif LED_SUPPORT
diff --git a/code/espurna/relay.ino b/code/espurna/relay.ino
index 1c361a60..f738187e 100644
--- a/code/espurna/relay.ino
+++ b/code/espurna/relay.ino
@@ -194,7 +194,9 @@ void _relayProcess(bool mode) {
         #endif
 
         // Flag relay-based LEDs to update status
-        ledUpdate(true);
+        #if LED_SUPPORT
+            ledUpdate(true);
+        #endif
 
         _relays[id].report = false;
         _relays[id].group_report = false;
diff --git a/code/espurna/settings.ino b/code/espurna/settings.ino
index 89a2cd54..19013663 100644
--- a/code/espurna/settings.ino
+++ b/code/espurna/settings.ino
@@ -375,19 +375,30 @@ size_t settingsMaxSize() {
 
 bool settingsRestoreJson(JsonObject& data) {
 
+    // Check this is an ESPurna configuration file (must have "app":"ESPURNA")
     const char* app = data["app"];
-    if (strcmp(app, APP_NAME) != 0) return false;
+    if (!app || strcmp(app, APP_NAME) != 0) {
+        DEBUG_MSG_P(PSTR("[SETTING] Wrong or missing 'app' key\n"));
+        return false;
+    }
 
-    for (unsigned int i = EEPROM_DATA_END; i < SPI_FLASH_SEC_SIZE; i++) {
-        EEPROMr.write(i, 0xFF);
+    // Clear settings
+    bool is_backup = data["backup"];
+    if (is_backup) {
+        for (unsigned int i = EEPROM_DATA_END; i < SPI_FLASH_SEC_SIZE; i++) {
+            EEPROMr.write(i, 0xFF);
+        }
     }
 
+    // Dump settings to memory buffer
     for (auto element : data) {
         if (strcmp(element.key, "app") == 0) continue;
         if (strcmp(element.key, "version") == 0) continue;
+        if (strcmp(element.key, "backup") == 0) continue;
         setSetting(element.key, element.value.as<char*>());
     }
 
+    // Persist to EEPROM
     saveSettings();
 
     DEBUG_MSG_P(PSTR("[SETTINGS] Settings restored successfully\n"));
diff --git a/code/espurna/web.ino b/code/espurna/web.ino
index b26b64d3..7086bffd 100644
--- a/code/espurna/web.ino
+++ b/code/espurna/web.ino
@@ -88,14 +88,17 @@ void _onGetConfig(AsyncWebServerRequest *request) {
     response->addHeader("X-Content-Type-Options", "nosniff");
     response->addHeader("X-Frame-Options", "deny");
 
-    response->printf("{\n  \"app\": \"%s\",\n  \"version\": \"%s\"", APP_NAME, APP_VERSION);
+    response->printf("{\n\"app\": \"%s\"", APP_NAME);
+    response->printf(",\n\"version\": \"%s\"", APP_VERSION);
+    response->printf(",\n\"backup\": \"1\"");
+    response->printf(",\n\"timestamp\": \"%s\"", ntpDateTime().c_str());
 
     // Write the keys line by line (not sorted)
     unsigned long count = settingsKeyCount();
     for (unsigned int i=0; i<count; i++) {
         String key = settingsKeyName(i);
         String value = getSetting(key);
-        response->printf(",\n  \"%s\": \"%s\"", key.c_str(), value.c_str());
+        response->printf(",\n\"%s\": \"%s\"", key.c_str(), value.c_str());
     }
     response->printf("\n}");
 
@@ -196,9 +199,9 @@ void _onHome(AsyncWebServerRequest *request) {
 
         response->addHeader("Content-Encoding", "gzip");
         response->addHeader("Last-Modified", _last_modified);
-	response->addHeader("X-XSS-Protection", "1; mode=block");
-	response->addHeader("X-Content-Type-Options", "nosniff");
-	response->addHeader("X-Frame-Options", "deny");
+        response->addHeader("X-XSS-Protection", "1; mode=block");
+        response->addHeader("X-Content-Type-Options", "nosniff");
+        response->addHeader("X-Frame-Options", "deny");
         request->send(response);
 
     }
diff --git a/code/gulpfile.js b/code/gulpfile.js
index a6e6fa93..d9edbdbd 100644
--- a/code/gulpfile.js
+++ b/code/gulpfile.js
@@ -96,14 +96,14 @@ var buildHeaderFile = function() {
 
         cb(0, destination);
 
-   });
+    });
 
 }
 
 var htmllintReporter = function(filepath, issues) {
-	if (issues.length > 0) {
-		issues.forEach(function (issue) {
-			console.info(
+    if (issues.length > 0) {
+        issues.forEach(function (issue) {
+            console.info(
                 '[gulp-htmllint] ' +
                 filepath + ' [' +
                 issue.line + ',' +
@@ -111,9 +111,9 @@ var htmllintReporter = function(filepath, issues) {
                 '(' + issue.code + ') ' +
                 issue.msg
             );
-		});
-		process.exitCode = 1;
-	}
+        });
+        process.exitCode = 1;
+    }
 };
 
 var buildWebUI = function(module) {
diff --git a/code/platformio.ini b/code/platformio.ini
index 88bf2d9b..3203f89b 100644
--- a/code/platformio.ini
+++ b/code/platformio.ini
@@ -1416,7 +1416,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DEXS_WIFI_RELAY_V31
+build_flags = ${common.build_flags_4m1m} -DEXS_WIFI_RELAY_V31
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -1427,7 +1427,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DEXS_WIFI_RELAY_V31
+build_flags = ${common.build_flags_4m1m} -DEXS_WIFI_RELAY_V31
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -1730,7 +1730,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DEUROMATE_WIFI_STECKER_SCHUKO
+build_flags = ${common.build_flags_1m0m} -DEUROMATE_WIFI_STECKER_SCHUKO
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -1741,7 +1741,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DEUROMATE_WIFI_STECKER_SCHUKO
+build_flags = ${common.build_flags_1m0m} -DEUROMATE_WIFI_STECKER_SCHUKO
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -1754,7 +1754,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DTONBUX_POWERSTRIP02
+build_flags = ${common.build_flags_1m0m} -DTONBUX_POWERSTRIP02
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -1765,7 +1765,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DTONBUX_POWERSTRIP02
+build_flags = ${common.build_flags_1m0m} -DTONBUX_POWERSTRIP02
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -1778,7 +1778,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DLINGAN_SWA1
+build_flags = ${common.build_flags_1m0m} -DLINGAN_SWA1
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -1789,7 +1789,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DLINGAN_SWA1
+build_flags = ${common.build_flags_1m0m} -DLINGAN_SWA1
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -1967,11 +1967,11 @@ extra_scripts = ${common.extra_scripts}
 [env:arniex-swifitch]
 platform = ${common.platform}
 framework = ${common.framework}
-board = ${common.board_1m}
+board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DARNIEX_SWIFITCH
+build_flags = ${common.build_flags_4m1m} -DARNIEX_SWIFITCH
 extra_scripts = ${common.extra_scripts}
 monitor_speed = ${common.monitor_speed}
 
@@ -1982,7 +1982,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DARNIEX_SWIFITCH
+build_flags = ${common.build_flags_4m1m} -DARNIEX_SWIFITCH
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -2020,7 +2020,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DLUANI_HVIO
+build_flags = ${common.build_flags_4m1m} -DLUANI_HVIO
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -2031,7 +2031,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DZLUANI_HVIO
+build_flags = ${common.build_flags_4m1m} -DLUANI_HVIO
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -2045,7 +2045,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DNEO_COOLCAM_NAS_WR01W
+build_flags = ${common.build_flags_1m0m} -DNEO_COOLCAM_NAS_WR01W
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -2056,7 +2056,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DNEO_COOLCAM_NAS_WR01W
+build_flags = ${common.build_flags_1m0m} -DNEO_COOLCAM_NAS_WR01W
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -2069,7 +2069,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DESTINK_WIFI_POWER_STRIP
+build_flags = ${common.build_flags_1m0m} -DESTINK_WIFI_POWER_STRIP
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -2080,7 +2080,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_4m1m} -DESTINK_WIFI_POWER_STRIP
+build_flags = ${common.build_flags_1m0m} -DESTINK_WIFI_POWER_STRIP
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -2217,7 +2217,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DALLNET_4DUINO_IOT_WLAN_RELAIS
+build_flags = ${common.build_flags_4m1m} -DALLNET_4DUINO_IOT_WLAN_RELAIS
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -2228,7 +2228,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DALLNET_4DUINO_IOT_WLAN_RELAIS
+build_flags = ${common.build_flags_4m1m} -DALLNET_4DUINO_IOT_WLAN_RELAIS
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -2289,7 +2289,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DNODEMCU_BASIC -DGEIGER_SUPPORT=1 -DEVENTS_SUPPORT=0 -DINFLUXDB_SUPPORT=1 -DALEXA_SUPPORT=0 -DALEXA_ENABLED=0
+build_flags = ${common.build_flags_4m1m} -DNODEMCU_BASIC -DGEIGER_SUPPORT=1 -DEVENTS_SUPPORT=0 -DINFLUXDB_SUPPORT=1 -DALEXA_SUPPORT=0 -DALEXA_ENABLED=0
 upload_speed = ${common.upload_speed_fast}
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
@@ -2301,7 +2301,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DNODEMCU_BASIC -DGEIGER_SUPPORT=1 -DEVENTS_SUPPORT=0 -DINFLUXDB_SUPPORT=1 -DALEXA_SUPPORT=0 -DALEXA_ENABLED=0
+build_flags = ${common.build_flags_4m1m} -DNODEMCU_BASIC -DGEIGER_SUPPORT=1 -DEVENTS_SUPPORT=0 -DINFLUXDB_SUPPORT=1 -DALEXA_SUPPORT=0 -DALEXA_ENABLED=0
 upload_speed = ${common.upload_speed_fast}
 monitor_speed = ${common.monitor_speed}
 upload_port = ${common.upload_port}
@@ -2341,7 +2341,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DBH_ONOFRE
+build_flags = ${common.build_flags_4m1m} -DBH_ONOFRE
 upload_speed = ${common.upload_speed_fast}
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
@@ -2353,7 +2353,7 @@ board = ${common.board_4m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DBH_ONOFRE
+build_flags = ${common.build_flags_4m1m} -DBH_ONOFRE
 upload_speed = ${common.upload_speed_fast}
 monitor_speed = ${common.monitor_speed}
 upload_port = ${common.upload_port}