diff --git a/App/app/breakout.c b/App/app/breakout.c
index 3019745c..3e1ff4e9 100644
--- a/App/app/breakout.c
+++ b/App/app/breakout.c
@@ -23,7 +23,7 @@
 static uint32_t randSeed = 1;
 static uint8_t blockAnim = 0;
 
-bool isInitialized = false;
+static bool isInitialized = false;
 bool isPaused = false;
 bool isBeep = false;
 
@@ -36,7 +36,7 @@ int16_t ballCount = BALL_NUMBER;
 
 char str[12];
 
-KeyboardState kbd = {KEY_INVALID, KEY_INVALID, 0};
+static KeyboardState kbd = {KEY_INVALID, KEY_INVALID, 0};
 
 Brick brick[BRICK_NUMBER];
 Racket racket;
@@ -403,7 +403,7 @@ static void OnKeyDown(uint8_t key)
 
 
 // Key 
-KEY_Code_t GetKey()
+static KEY_Code_t GetKey()
 {
     KEY_Code_t btn = KEYBOARD_Poll();
     if (btn == KEY_INVALID && GPIO_IsPttPressed())
@@ -414,7 +414,7 @@ KEY_Code_t GetKey()
 }
 
 // HandleUserInput 
-bool HandleUserInput()
+static bool HandleUserInput()
 {
     // Store previous key state
     kbd.prev = kbd.current;
diff --git a/App/app/breakout.h b/App/app/breakout.h
index 357d173d..afea94c1 100644
--- a/App/app/breakout.h
+++ b/App/app/breakout.h
@@ -14,6 +14,10 @@
  *     limitations under the License.
  */
 
+#pragma once
+
+#include "keyboard_state.h"
+
 #include "../bitmaps.h"
 #include "../board.h"
 #include "py32f0xx.h"
@@ -66,13 +70,6 @@ typedef struct {
     int8_t dy;  // move y
 } Ball;
 
-typedef struct KeyboardState
-{
-    KEY_Code_t current;
-    KEY_Code_t prev;
-    uint8_t counter;
-} KeyboardState;
-
 void initWall(void);
 void drawWall(void);
 void initRacket(void);
diff --git a/App/app/keyboard_state.h b/App/app/keyboard_state.h
new file mode 100644
index 00000000..d14314fe
--- /dev/null
+++ b/App/app/keyboard_state.h
@@ -0,0 +1,24 @@
+/* Copyright 2025 Armel F4HWN
+ * https://github.com/armel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *     Unless required by applicable law or agreed to in writing, software
+ *     distributed under the License is distributed on an "AS IS" BASIS,
+ *     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *     See the License for the specific language governing permissions and
+ *     limitations under the License.
+ */
+
+#pragma once
+#include "../driver/keyboard.h"
+
+typedef struct {
+    KEY_Code_t current;
+    KEY_Code_t prev;
+    uint8_t    counter;
+} KeyboardState;
diff --git a/App/app/spectrum.c b/App/app/spectrum.c
index f681c5ac..65ba368f 100644
--- a/App/app/spectrum.c
+++ b/App/app/spectrum.c
@@ -50,7 +50,7 @@ const uint16_t RSSI_MAX_VALUE = 65535;
 static uint32_t initialFreq;
 static char String[32];
 
-bool isInitialized = false;
+static bool isInitialized = false;
 bool isListening = true;
 bool monitorMode = false;
 bool redrawStatus = true;
@@ -64,7 +64,7 @@ State currentState = SPECTRUM, previousState = SPECTRUM;
 
 PeakInfo peak;
 ScanInfo scanInfo;
-KeyboardState kbd = {KEY_INVALID, KEY_INVALID, 0};
+static KeyboardState kbd = {KEY_INVALID, KEY_INVALID, 0};
 
 #ifdef ENABLE_SCAN_RANGES
 static uint16_t blacklistFreqs[15];
@@ -268,7 +268,7 @@ static void GUI_DisplaySmallest(const char *pString, uint8_t x, uint8_t y,
 
 // Utility functions
 
-KEY_Code_t GetKey()
+static KEY_Code_t GetKey()
 {
     KEY_Code_t btn = KEYBOARD_Poll();
     if (btn == KEY_INVALID && GPIO_IsPttPressed())
@@ -1495,7 +1495,7 @@ static void Render()
     ST7565_BlitFullScreen();
 }
 
-bool HandleUserInput()
+static bool HandleUserInput()
 {
     kbd.prev = kbd.current;
     kbd.current = GetKey();
diff --git a/App/app/spectrum.h b/App/app/spectrum.h
index b7862a9b..a0e81451 100644
--- a/App/app/spectrum.h
+++ b/App/app/spectrum.h
@@ -17,6 +17,10 @@
 #ifndef SPECTRUM_H
 #define SPECTRUM_H
 
+#pragma once
+
+#include "keyboard_state.h"
+
 #include "../bitmaps.h"
 #include "../board.h"
 #include "py32f0xx.h"
@@ -156,13 +160,6 @@ typedef struct SpectrumSettings
     bool backlightState;
 } SpectrumSettings;
 
-typedef struct KeyboardState
-{
-    KEY_Code_t current;
-    KEY_Code_t prev;
-    uint8_t counter;
-} KeyboardState;
-
 typedef struct ScanInfo
 {
     uint16_t rssi, rssiMin, rssiMax;
diff --git a/App/driver/bk4829.c b/App/driver/bk4829.c
index 4cbca2e3..4a84de02 100644
--- a/App/driver/bk4829.c
+++ b/App/driver/bk4829.c
@@ -38,8 +38,8 @@
 
 static const uint16_t FSK_RogerTable[7] = {0xF1A2, 0x7446, 0x61A4, 0x6544, 0x4E8A, 0xE044, 0xEA84};
 
-static const uint8_t DTMF_TONE1_GAIN = 65;
-static const uint8_t DTMF_TONE2_GAIN = 93;
+//static const uint8_t DTMF_TONE1_GAIN = 65;
+//static const uint8_t DTMF_TONE2_GAIN = 93;
 
 static uint16_t gBK4819_GpioOutState;