diff --git a/packages/uhk-agent/src/electron-main.ts b/packages/uhk-agent/src/electron-main.ts
index 093b9c92..d5035166 100644
--- a/packages/uhk-agent/src/electron-main.ts
+++ b/packages/uhk-agent/src/electron-main.ts
@@ -118,13 +118,13 @@ function createWindow() {
     });
 
     // Emitted when the window is closed.
-    win.on('closed', () => {
+    win.on('closed', async () => {
         // Dereference the window object, usually you would store windows
         // in an array if your app supports multi windows, this is the time
         // when you should delete the corresponding element.
         logger.info('[Electron Main] win closed');
         win = null;
-        deviceService.close();
+        await deviceService.close();
         deviceService = null;
         appUpdateService = null;
         appService = null;
diff --git a/packages/uhk-agent/src/services/device.service.ts b/packages/uhk-agent/src/services/device.service.ts
index 1cfc2e68..55825d10 100644
--- a/packages/uhk-agent/src/services/device.service.ts
+++ b/packages/uhk-agent/src/services/device.service.ts
@@ -14,8 +14,6 @@ import {
     UpdateFirmwareData
 } from 'uhk-common';
 import { snooze, UhkHidDevice, UhkOperations } from 'uhk-usb';
-import { Subscription, interval, from } from 'rxjs';
-import { distinctUntilChanged, startWith, switchMap, tap } from 'rxjs/operators';
 import { emptyDir } from 'fs-extra';
 import * as path from 'path';
 
@@ -35,7 +33,8 @@ import {
  * - Read UserConfiguration from the UHK Device
  */
 export class DeviceService {
-    private pollTimer$: Subscription;
+    private _pollerAllowed: boolean;
+    private _uhkDevicePolling: boolean;
     private queueManager = new QueueManager();
 
     constructor(private logService: LogService,
@@ -43,7 +42,11 @@ export class DeviceService {
                 private device: UhkHidDevice,
                 private operations: UhkOperations,
                 private rootDir: string) {
-        this.pollUhkDevice();
+        this.startPollUhkDevice();
+        this.uhkDevicePoller()
+            .catch(error => {
+                this.logService.error('[DeviceService] UHK Device poller error', error);
+            });
 
         ipcMain.on(IpcEvents.device.saveUserConfiguration, (...args: any[]) => {
             this.queueManager.add({
@@ -72,7 +75,7 @@ export class DeviceService {
             });
         });
 
-        ipcMain.on(IpcEvents.device.startConnectionPoller, this.pollUhkDevice.bind(this));
+        ipcMain.on(IpcEvents.device.startConnectionPoller, this.startPollUhkDevice.bind(this));
 
         ipcMain.on(IpcEvents.device.recoveryDevice, (...args: any[]) => {
             this.queueManager.add({
@@ -103,6 +106,8 @@ export class DeviceService {
         let response: ConfigurationReply;
 
         try {
+            await this.stopPollUhkDevice();
+
             await this.device.waitUntilKeyboardBusy();
             const result = await this.operations.loadConfigurations();
             const modules: HardwareModules = await this.getHardwareModules(false);
@@ -123,6 +128,7 @@ export class DeviceService {
             };
         } finally {
             this.device.close();
+            this.startPollUhkDevice();
         }
 
         event.sender.send(IpcEvents.device.loadConfigurationReply, JSON.stringify(response));
@@ -136,8 +142,7 @@ export class DeviceService {
                 leftModuleInfo: await this.operations.getLeftModuleVersionInfo(),
                 rightModuleInfo: await this.operations.getRightModuleVersionInfo()
             };
-        }
-        catch (err) {
+        } catch (err) {
             if (!catchError) {
                 return err;
             }
@@ -151,8 +156,8 @@ export class DeviceService {
         }
     }
 
-    public close(): void {
-        this.stopPollTimer();
+    public async close(): Promise<void> {
+        await this.stopPollUhkDevice();
         this.logService.info('[DeviceService] Device connection checker stopped.');
     }
 
@@ -168,7 +173,7 @@ export class DeviceService {
             this.logService.debug('Device right firmware version:', hardwareModules.rightModuleInfo.firmwareVersion);
             this.logService.debug('Device left firmware version:', hardwareModules.leftModuleInfo.firmwareVersion);
 
-            this.stopPollTimer();
+            await this.stopPollUhkDevice();
             this.device.resetDeviceCache();
 
             if (data.firmware) {
@@ -179,8 +184,7 @@ export class DeviceService {
 
                 await this.operations.updateRightFirmware(firmwarePathData.rightFirmwarePath);
                 await this.operations.updateLeftModule(firmwarePathData.leftFirmwarePath);
-            }
-            else {
+            } else {
                 const packageJsonPath = path.join(this.rootDir, 'packages/firmware/package.json');
                 const packageJson = await getPackageJsonFromPathAsync(packageJsonPath);
                 this.logService.debug('New firmware version:', packageJson.firmwareVersion);
@@ -192,7 +196,7 @@ export class DeviceService {
             response.success = true;
             response.modules = await this.getHardwareModules(false);
         } catch (error) {
-            const err = {message: error.message, stack: error.stack};
+            const err = { message: error.message, stack: error.stack };
             this.logService.error('[DeviceService] updateFirmware error', err);
 
             response.modules = await this.getHardwareModules(true);
@@ -205,7 +209,7 @@ export class DeviceService {
 
         await snooze(500);
 
-        this.pollUhkDevice();
+        this.startPollUhkDevice();
 
         event.sender.send(IpcEvents.device.updateFirmwareReply, response);
     }
@@ -214,14 +218,14 @@ export class DeviceService {
         const response = new FirmwareUpgradeIpcResponse();
 
         try {
-            this.stopPollTimer();
+            await this.stopPollUhkDevice();
 
             await this.operations.updateRightFirmware();
 
             response.modules = await this.getHardwareModules(false);
             response.success = true;
         } catch (error) {
-            const err = {message: error.message, stack: error.stack};
+            const err = { message: error.message, stack: error.stack };
             this.logService.error('[DeviceService] updateFirmware error', err);
 
             response.modules = await this.getHardwareModules(true);
@@ -236,28 +240,51 @@ export class DeviceService {
         await this.device.enableUsbStackTest();
     }
 
+    private startPollUhkDevice(): void {
+        this._pollerAllowed = true;
+    }
+
+    private async stopPollUhkDevice(): Promise<void> {
+        return new Promise<void>(async resolve => {
+            this._pollerAllowed = false;
+
+            while (true) {
+                if (!this._uhkDevicePolling) {
+                    return resolve();
+                }
+
+                await snooze(100);
+            }
+        });
+    }
+
     /**
      * HID API not support device attached and detached event.
      * This method check the keyboard is attached to the computer or not.
-     * Every second check the HID device list.
+     * The halves are connected and merged or not.
+     * Every 250ms check the HID device list.
      * @private
      */
-    private pollUhkDevice(): void {
-        if (this.pollTimer$) {
-            return;
-        }
+    private async uhkDevicePoller(): Promise<void> {
+        let savedState: DeviceConnectionState;
 
-        this.pollTimer$ = interval(1000)
-            .pipe(
-                startWith(0),
-                switchMap(() => from(this.device.getDeviceConnectionStateAsync())),
-                distinctUntilChanged<DeviceConnectionState>(isEqual),
-                tap((state: DeviceConnectionState) => {
+        while (true) {
+            if (this._pollerAllowed) {
+
+                this._uhkDevicePolling = true;
+
+                const state = await this.device.getDeviceConnectionStateAsync();
+                if (!isEqual(state, savedState)) {
+                    savedState = state;
                     this.win.webContents.send(IpcEvents.device.deviceConnectionStateChanged, state);
                     this.logService.info('[DeviceService] Device connection state changed to:', state);
-                })
-            )
-            .subscribe();
+                }
+
+                this._uhkDevicePolling = false;
+            }
+
+            await snooze(250);
+        }
     }
 
     private async saveUserConfiguration(event: Electron.Event, args: Array<string>): Promise<void> {
@@ -265,32 +292,23 @@ export class DeviceService {
         const data: SaveUserConfigurationData = JSON.parse(args[0]);
 
         try {
+            await this.stopPollUhkDevice();
             await backupUserConfiguration(data);
 
             const buffer = mapObjectToUserConfigBinaryBuffer(data.configuration);
             await this.operations.saveUserConfiguration(buffer);
 
             response.success = true;
-        }
-        catch (error) {
+        } catch (error) {
             this.logService.error('[DeviceService] Transferring error', error);
-            response.error = {message: error.message};
+            response.error = { message: error.message };
         } finally {
             this.device.close();
+            this.startPollUhkDevice();
         }
 
         event.sender.send(IpcEvents.device.saveUserConfigurationReply, response);
 
         return Promise.resolve();
     }
-
-    private stopPollTimer(): void {
-        if (!this.pollTimer$) {
-            return;
-        }
-
-        this.pollTimer$.unsubscribe();
-        this.pollTimer$ = null;
-
-    }
 }
diff --git a/packages/uhk-common/src/models/device-connection-state.ts b/packages/uhk-common/src/models/device-connection-state.ts
index 1cdb6063..1c627a15 100644
--- a/packages/uhk-common/src/models/device-connection-state.ts
+++ b/packages/uhk-common/src/models/device-connection-state.ts
@@ -1,4 +1,5 @@
 import { UdevRulesInfo } from './udev-rules-info';
+import { HalvesInfo } from './halves-info';
 
 export interface DeviceConnectionState {
     connected: boolean;
@@ -6,4 +7,5 @@ export interface DeviceConnectionState {
     bootloaderActive: boolean;
     zeroInterfaceAvailable: boolean;
     udevRulesInfo: UdevRulesInfo;
+    halvesInfo: HalvesInfo;
 }
diff --git a/packages/uhk-common/src/models/halves-info.ts b/packages/uhk-common/src/models/halves-info.ts
new file mode 100644
index 00000000..e73f61da
--- /dev/null
+++ b/packages/uhk-common/src/models/halves-info.ts
@@ -0,0 +1,4 @@
+export interface HalvesInfo {
+    areHalvesMerged: boolean;
+    isLeftHalfConnected: boolean;
+}
diff --git a/packages/uhk-common/src/models/index.ts b/packages/uhk-common/src/models/index.ts
index d9d4eabe..8248fe95 100644
--- a/packages/uhk-common/src/models/index.ts
+++ b/packages/uhk-common/src/models/index.ts
@@ -11,3 +11,4 @@ export * from './hardware-module-info';
 export * from './save-user-configuration-data';
 export * from './udev-rules-info';
 export * from './update-firmware-data';
+export * from './halves-info';
diff --git a/packages/uhk-usb/src/uhk-hid-device.ts b/packages/uhk-usb/src/uhk-hid-device.ts
index bf24a248..c7e493c7 100644
--- a/packages/uhk-usb/src/uhk-hid-device.ts
+++ b/packages/uhk-usb/src/uhk-hid-device.ts
@@ -2,7 +2,7 @@ import { Device, devices, HID } from 'node-hid';
 import { pathExists } from 'fs-extra';
 import * as path from 'path';
 import { platform } from 'os';
-import { CommandLineArgs, DeviceConnectionState, isEqualArray, LogService, UdevRulesInfo } from 'uhk-common';
+import { CommandLineArgs, DeviceConnectionState, HalvesInfo, isEqualArray, LogService, UdevRulesInfo } from 'uhk-common';
 
 import {
     ConfigBufferId,
@@ -89,7 +89,8 @@ export class UhkHidDevice {
             connected: false,
             zeroInterfaceAvailable: false,
             hasPermission: this.hasPermission(),
-            udevRulesInfo: await this.getUdevInfoAsync()
+            udevRulesInfo: await this.getUdevInfoAsync(),
+            halvesInfo: { areHalvesMerged: true, isLeftHalfConnected: true }
         };
 
         for (const dev of devs) {
@@ -105,6 +106,12 @@ export class UhkHidDevice {
             }
         }
 
+        if (result.connected && result.hasPermission && result.zeroInterfaceAvailable) {
+            result.halvesInfo = await this.getHalvesStates();
+        } else if (!result.connected) {
+            this._device = undefined;
+        }
+
         return result;
     }
 
@@ -253,6 +260,15 @@ export class UhkHidDevice {
         await this.write(transfer);
     }
 
+    async getHalvesStates(): Promise<HalvesInfo> {
+        const buffer = await this.write(Buffer.from([UsbCommand.GetDeviceState]));
+
+        return {
+            areHalvesMerged: buffer[2] !== 0,
+            isLeftHalfConnected: buffer[3] !== 0
+        };
+    }
+
     /**
      * Return the stored version of HID device. If not exist try to initialize.
      * @returns {HID}
diff --git a/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.html b/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.html
index 7ff7f5d0..693e2235 100644
--- a/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.html
+++ b/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.html
@@ -1,7 +1,7 @@
 <svg-keyboard *ngFor="let layer of layers; let index = index; trackBy: trackKeyboard"
               [@layerState]="layerAnimationState[index]"
               [moduleConfig]="layer.modules"
-              [halvesSplit]="halvesSplit"
+              [halvesInfo]="halvesInfo"
               [capturingEnabled]="capturingEnabled"
               [selectedKey]="selectedKey"
               [selected]="selectedKey?.layerId === index"
diff --git a/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.scss b/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.scss
index 5250ea1c..a0404c4e 100644
--- a/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.scss
+++ b/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.scss
@@ -1,5 +1,5 @@
 svg-keyboard {
-    width: 95%;
+    width: 99%;
     max-width: 1400px;
     position: absolute;
     left: 0;
diff --git a/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.ts b/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.ts
index eb55b3a8..3d07a124 100644
--- a/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.ts
+++ b/packages/uhk-web/src/app/components/keyboard/slider/keyboard-slider.component.ts
@@ -1,6 +1,6 @@
 import { ChangeDetectionStrategy, Component, EventEmitter, Input, OnChanges, Output, SimpleChanges } from '@angular/core';
 import { animate, keyframes, state, style, transition, trigger } from '@angular/animations';
-import { Layer } from 'uhk-common';
+import { HalvesInfo, Layer } from 'uhk-common';
 
 import { KeyboardLayout } from '../../../keyboard/keyboard-layout.enum';
 import {
@@ -83,7 +83,7 @@ export class KeyboardSliderComponent implements OnChanges {
     @Input() layers: Layer[];
     @Input() currentLayer: number;
     @Input() capturingEnabled: boolean;
-    @Input() halvesSplit: boolean;
+    @Input() halvesInfo: HalvesInfo;
     @Input() selectedKey: { layerId: number, moduleId: number, keyId: number };
     @Input() keyboardLayout = KeyboardLayout.ANSI;
     @Input() description: string;
diff --git a/packages/uhk-web/src/app/components/keymap/edit/keymap-edit.component.html b/packages/uhk-web/src/app/components/keymap/edit/keymap-edit.component.html
index dec91343..932e8cef 100644
--- a/packages/uhk-web/src/app/components/keymap/edit/keymap-edit.component.html
+++ b/packages/uhk-web/src/app/components/keymap/edit/keymap-edit.component.html
@@ -3,7 +3,7 @@
                    [deletable]="deletable$ | async"
                    (downloadClick)="downloadKeymap()"></keymap-header>
     <svg-keyboard-wrap [keymap]="keymap"
-                       [halvesSplit]="keyboardSplit"
+                       [halvesInfo]="halvesInfo$ | async"
                        [keyboardLayout]="keyboardLayout$ | async"
                        [allowLayerDoubleTap]="allowLayerDoubleTap$ | async"
                        [lastEditedKey]="lastEditedKey$ | async"
diff --git a/packages/uhk-web/src/app/components/keymap/edit/keymap-edit.component.ts b/packages/uhk-web/src/app/components/keymap/edit/keymap-edit.component.ts
index 92605d26..5a2e79be 100644
--- a/packages/uhk-web/src/app/components/keymap/edit/keymap-edit.component.ts
+++ b/packages/uhk-web/src/app/components/keymap/edit/keymap-edit.component.ts
@@ -1,7 +1,7 @@
-import { ChangeDetectionStrategy, ChangeDetectorRef, Component, HostListener, OnDestroy } from '@angular/core';
+import { ChangeDetectionStrategy, ChangeDetectorRef, Component, OnDestroy } from '@angular/core';
 import { ActivatedRoute } from '@angular/router';
 import { Store } from '@ngrx/store';
-import { Keymap } from 'uhk-common';
+import { HalvesInfo, Keymap } from 'uhk-common';
 
 import { Observable, Subscription } from 'rxjs';
 import { combineLatest, first, map, pluck, switchMap } from 'rxjs/operators';
@@ -15,7 +15,8 @@ import {
     layerDoubleTapSupported,
     AppState,
     getKeyboardLayout,
-    lastEditedKey
+    lastEditedKey,
+    getHalvesInfo
 } from '../../../store';
 import { KeyboardLayout } from '../../../keyboard/keyboard-layout.enum';
 import { EditDescriptionAction, SelectKeymapAction } from '../../../store/actions/keymap';
@@ -33,13 +34,12 @@ import { LastEditedKey } from '../../../models';
 })
 export class KeymapEditComponent implements OnDestroy {
 
-    keyboardSplit: boolean;
-
     deletable$: Observable<boolean>;
     keymap$: Observable<Keymap>;
     keyboardLayout$: Observable<KeyboardLayout>;
     allowLayerDoubleTap$: Observable<boolean>;
     lastEditedKey$: Observable<LastEditedKey>;
+    halvesInfo$: Observable<HalvesInfo>;
     keymap: Keymap;
 
     private routeSubscription: Subscription;
@@ -67,6 +67,7 @@ export class KeymapEditComponent implements OnDestroy {
         this.keyboardLayout$ = store.select(getKeyboardLayout);
         this.allowLayerDoubleTap$ = store.select(layerDoubleTapSupported);
         this.lastEditedKey$ = store.select(lastEditedKey);
+        this.halvesInfo$ = store.select(getHalvesInfo);
     }
 
     ngOnDestroy(): void {
@@ -94,11 +95,6 @@ export class KeymapEditComponent implements OnDestroy {
             });
     }
 
-    @HostListener('window:keydown.alt.s', ['$event'])
-    toggleKeyboardSplit() {
-        this.keyboardSplit = !this.keyboardSplit;
-    }
-
     descriptionChanged(event: ChangeKeymapDescription): void {
         this.store.dispatch(new EditDescriptionAction(event));
     }
diff --git a/packages/uhk-web/src/app/components/svg/keyboard/svg-keyboard.component.html b/packages/uhk-web/src/app/components/svg/keyboard/svg-keyboard.component.html
index e74f8497..ee3c6ad2 100644
--- a/packages/uhk-web/src/app/components/svg/keyboard/svg-keyboard.component.html
+++ b/packages/uhk-web/src/app/components/svg/keyboard/svg-keyboard.component.html
@@ -11,6 +11,7 @@
            [keyActions]="moduleConfig[i].keyActions"
            [selectedKey]="selectedKey"
            [@split]="moduleAnimationStates[i]"
+           [@fadeKeyboard]="moduleVisibilityAnimationStates[i]"
            [selected]="selectedKey?.moduleId === i"
            [lastEdited]="lastEditedKey?.moduleId === i"
            [lastEditedKeyId]="lastEditedKey?.key"
diff --git a/packages/uhk-web/src/app/components/svg/keyboard/svg-keyboard.component.ts b/packages/uhk-web/src/app/components/svg/keyboard/svg-keyboard.component.ts
index 1bae72dd..784b3975 100644
--- a/packages/uhk-web/src/app/components/svg/keyboard/svg-keyboard.component.ts
+++ b/packages/uhk-web/src/app/components/svg/keyboard/svg-keyboard.component.ts
@@ -1,7 +1,7 @@
 import { Component, EventEmitter, Input, Output, SimpleChanges, ChangeDetectionStrategy } from '@angular/core';
 import { animate, state, trigger, style, transition } from '@angular/animations';
 import { DomSanitizer, SafeStyle } from '@angular/platform-browser';
-import { Module } from 'uhk-common';
+import { HalvesInfo, Module } from 'uhk-common';
 
 import { SvgModule } from '../module';
 import { SvgModuleProviderService } from '../../../services/svg-module-provider.service';
@@ -23,13 +23,23 @@ import { LastEditedKey } from '../../../models';
     animations: [
         trigger('split', [
             state('rotateLeft', style({
-                transform: 'translate(-3%, 15%) rotate(4deg) scale(0.92, 0.92)'
+                transform: 'translate(2%, 30%) rotate(10.8deg) scale(0.80, 0.80)'
             })),
             state('rotateRight', style({
-                transform: 'translate(3%, 15%) rotate(-4deg) scale(0.92, 0.92)'
+                transform: 'translate(-2%, 30.7%) rotate(-10deg) scale(0.80, 0.80)'
             })),
             transition('* <=> *', animate(500))
         ]),
+        trigger('fadeKeyboard', [
+            state('visible', style({
+                opacity: 1
+            })),
+            state('invisible', style({
+                opacity: 0
+            })),
+            transition('visible => invisible', animate(500)),
+            transition('invisible => visible', animate(500))
+        ]),
         trigger('fadeSeparator', [
             state('visible', style({
                 opacity: 1
@@ -37,8 +47,8 @@ import { LastEditedKey } from '../../../models';
             state('invisible', style({
                 opacity: 0
             })),
-            transition('visible => invisible', animate(500)),
-            transition('invisible => visible', animate(1500))
+            transition('visible => invisible', animate('200ms')),
+            transition('invisible => visible', animate('200ms 500ms'))
         ])
     ]
 })
@@ -47,7 +57,7 @@ export class SvgKeyboardComponent {
     @Input() capturingEnabled: boolean;
     @Input() selectedKey: { layerId: number, moduleId: number, keyId: number };
     @Input() selected: boolean;
-    @Input() halvesSplit: boolean;
+    @Input() halvesInfo: HalvesInfo;
     @Input() keyboardLayout = KeyboardLayout.ANSI;
     @Input() description: string;
     @Input() showDescription = false;
@@ -60,6 +70,7 @@ export class SvgKeyboardComponent {
     modules: SvgModule[];
     viewBox: string;
     moduleAnimationStates: string[];
+    moduleVisibilityAnimationStates: string[];
     separator: SvgSeparator;
     separatorStyle: SafeStyle;
     separatorAnimation = 'visible';
@@ -68,7 +79,6 @@ export class SvgKeyboardComponent {
                 private sanitizer: DomSanitizer) {
         this.modules = [];
         this.viewBox = '-520 582 1100 470';
-        this.halvesSplit = false;
         this.moduleAnimationStates = [];
     }
 
@@ -77,7 +87,7 @@ export class SvgKeyboardComponent {
     }
 
     ngOnChanges(changes: SimpleChanges) {
-        if (changes.halvesSplit) {
+        if (changes.halvesInfo) {
             this.updateModuleAnimationStates();
         }
 
@@ -110,12 +120,19 @@ export class SvgKeyboardComponent {
     }
 
     private updateModuleAnimationStates() {
-        if (this.halvesSplit) {
-            this.moduleAnimationStates = ['rotateRight', 'rotateLeft'];
-            this.separatorAnimation = 'invisible';
-        } else {
+        if (this.halvesInfo.areHalvesMerged) {
             this.moduleAnimationStates = [];
             this.separatorAnimation = 'visible';
+        } else {
+            this.moduleAnimationStates = ['rotateRight', 'rotateLeft'];
+            this.separatorAnimation = 'invisible';
+        }
+
+        if (this.halvesInfo.isLeftHalfConnected) {
+            this.moduleVisibilityAnimationStates = ['visible', 'visible'];
+        } else {
+            this.moduleVisibilityAnimationStates = ['visible', 'invisible'];
+
         }
     }
 
diff --git a/packages/uhk-web/src/app/components/svg/wrap/svg-keyboard-wrap.component.html b/packages/uhk-web/src/app/components/svg/wrap/svg-keyboard-wrap.component.html
index 95824550..a322e868 100644
--- a/packages/uhk-web/src/app/components/svg/wrap/svg-keyboard-wrap.component.html
+++ b/packages/uhk-web/src/app/components/svg/wrap/svg-keyboard-wrap.component.html
@@ -4,7 +4,7 @@
                      [currentLayer]="currentLayer"
                      [capturingEnabled]="popoverEnabled"
                      [selectedKey]="selectedKey"
-                     [halvesSplit]="halvesSplit"
+                     [halvesInfo]="halvesInfo"
                      [keyboardLayout]="keyboardLayout"
                      [description]="keymap.description"
                      [lastEditedKey]="lastEditedKey"
diff --git a/packages/uhk-web/src/app/components/svg/wrap/svg-keyboard-wrap.component.ts b/packages/uhk-web/src/app/components/svg/wrap/svg-keyboard-wrap.component.ts
index 3186cedb..b0527638 100644
--- a/packages/uhk-web/src/app/components/svg/wrap/svg-keyboard-wrap.component.ts
+++ b/packages/uhk-web/src/app/components/svg/wrap/svg-keyboard-wrap.component.ts
@@ -20,6 +20,7 @@ import { Store } from '@ngrx/store';
 import {
     camelCaseToSentence,
     capitalizeFirstLetter,
+    HalvesInfo,
     KeyAction,
     Keymap,
     KeystrokeAction,
@@ -65,7 +66,7 @@ export class SvgKeyboardWrapComponent implements OnInit, OnChanges {
     @Input() keymap: Keymap;
     @Input() popoverEnabled: boolean = true;
     @Input() tooltipEnabled: boolean = false;
-    @Input() halvesSplit: boolean;
+    @Input() halvesInfo: HalvesInfo;
     @Input() keyboardLayout: KeyboardLayout.ANSI;
     @Input() allowLayerDoubleTap: boolean;
     @Input() lastEditedKey: LastEditedKey;
diff --git a/packages/uhk-web/src/app/store/effects/device.ts b/packages/uhk-web/src/app/store/effects/device.ts
index 8cc38729..3fc618d0 100644
--- a/packages/uhk-web/src/app/store/effects/device.ts
+++ b/packages/uhk-web/src/app/store/effects/device.ts
@@ -3,7 +3,7 @@ import { Router } from '@angular/router';
 import { Action, Store } from '@ngrx/store';
 import { Actions, Effect, ofType } from '@ngrx/effects';
 import { EMPTY, Observable, of, timer } from 'rxjs';
-import { map, mergeMap, switchMap, tap, withLatestFrom } from 'rxjs/operators';
+import { distinctUntilChanged, map, mergeMap, switchMap, tap, withLatestFrom } from 'rxjs/operators';
 
 import {
     FirmwareUpgradeIpcResponse,
@@ -73,6 +73,14 @@ export class DeviceEffects {
 
                 return this.router.navigate(['/detection']);
             }),
+            distinctUntilChanged((
+                [prevAction, prevRoute, prevConnected],
+                [currAction, currRoute, currConnected]) => {
+
+                return prevConnected === currConnected &&
+                    prevAction.payload.hasPermission === currAction.payload.hasPermission &&
+                    prevAction.payload.zeroInterfaceAvailable === currAction.payload.zeroInterfaceAvailable;
+            }),
             switchMap(([action, route, connected]) => {
                 const payload = action.payload;
 
diff --git a/packages/uhk-web/src/app/store/index.ts b/packages/uhk-web/src/app/store/index.ts
index fc8ed8a6..d0704c9e 100644
--- a/packages/uhk-web/src/app/store/index.ts
+++ b/packages/uhk-web/src/app/store/index.ts
@@ -110,6 +110,7 @@ export const bootloaderActive = createSelector(deviceState, fromDevice.bootloade
 export const firmwareUpgradeFailed = createSelector(deviceState, fromDevice.firmwareUpgradeFailed);
 export const firmwareUpgradeSuccess = createSelector(deviceState, fromDevice.firmwareUpgradeSuccess);
 export const getUpdateUdevRules = createSelector(deviceState, fromDevice.updateUdevRules);
+export const getHalvesInfo = createSelector(deviceState, fromDevice.halvesInfo);
 
 export const getPrivilegePageState = createSelector(appState, getUpdateUdevRules, (app, updateUdevRules): PrivilagePageSate => {
     const permissionSetupFailed = !!app.permissionError;
diff --git a/packages/uhk-web/src/app/store/reducers/device.ts b/packages/uhk-web/src/app/store/reducers/device.ts
index ca92d42b..d7994363 100644
--- a/packages/uhk-web/src/app/store/reducers/device.ts
+++ b/packages/uhk-web/src/app/store/reducers/device.ts
@@ -1,5 +1,5 @@
 import { Action } from '@ngrx/store';
-import { HardwareModules, UdevRulesInfo } from 'uhk-common';
+import { HardwareModules, UdevRulesInfo, HalvesInfo } from 'uhk-common';
 
 import * as Device from '../actions/device';
 import * as App from '../actions/app';
@@ -24,6 +24,7 @@ export interface State {
     log: Array<XtermLog>;
     restoringUserConfiguration: boolean;
     hasBackupUserConfiguration: boolean;
+    halvesInfo: HalvesInfo;
 }
 
 export const initialState: State = {
@@ -47,7 +48,8 @@ export const initialState: State = {
     },
     log: [{ message: '', cssClass: XtermCssClass.standard }],
     restoringUserConfiguration: false,
-    hasBackupUserConfiguration: false
+    hasBackupUserConfiguration: false,
+    halvesInfo: { isLeftHalfConnected: true, areHalvesMerged: true }
 };
 
 export function reducer(state = initialState, action: Action): State {
@@ -60,7 +62,8 @@ export function reducer(state = initialState, action: Action): State {
                 hasPermission: data.hasPermission,
                 zeroInterfaceAvailable: data.zeroInterfaceAvailable,
                 bootloaderActive: data.bootloaderActive,
-                udevRuleInfo: data.udevRulesInfo
+                udevRuleInfo: data.udevRulesInfo,
+                halvesInfo: data.halvesInfo
             };
         }
 
@@ -249,3 +252,4 @@ export const bootloaderActive = (state: State) => state.bootloaderActive;
 export const firmwareUpgradeFailed = (state: State) => state.firmwareUpdateFailed;
 export const firmwareUpgradeSuccess = (state: State) => state.firmwareUpdateSuccess;
 export const updateUdevRules = (state: State) => state.udevRuleInfo === UdevRulesInfo.Different;
+export const halvesInfo = (state: State) => state.halvesInfo;