diff --git a/main/drivers/char_lcd.cpp b/main/drivers/char_lcd.cpp
index af0fa4b..7f3b0e3 100644
--- a/main/drivers/char_lcd.cpp
+++ b/main/drivers/char_lcd.cpp
@@ -1,10 +1,6 @@
 #include "char_lcd.h"
 
-#define CHAR_LCD_I2C_NUM I2C_NUM_0
-
-#define LCD_ADDR 0x27
-#define LCD_COLS 20
-#define LCD_ROWS 4
+i2c_lcd_pcf8574_handle_t lcd;
 
 static const char *TAG = "char_lcd";
 
diff --git a/main/drivers/char_lcd.h b/main/drivers/char_lcd.h
index d4003dc..dd7eeb0 100644
--- a/main/drivers/char_lcd.h
+++ b/main/drivers/char_lcd.h
@@ -2,6 +2,7 @@
 #define CHAR_LCD_H
 
 #include "i2c_lcd_pcf8574.h"
+#include <esp_log.h>
 
 #define CHAR_LCD_I2C_NUM I2C_NUM_0
 
@@ -9,9 +10,7 @@
 #define LCD_COLS 20
 #define LCD_ROWS 4
 
-i2c_lcd_pcf8574_handle_t lcd;
-
-static const char *CHAR_LCD_TAG = "char_lcd";
+extern i2c_lcd_pcf8574_handle_t lcd;
 
 void init_char_lcd(void);
 
diff --git a/main/drivers/game_timer.cpp b/main/drivers/game_timer.cpp
index 67b5590..027afb0 100644
--- a/main/drivers/game_timer.cpp
+++ b/main/drivers/game_timer.cpp
@@ -34,19 +34,19 @@ void stop_module_timer(void) {
 }
 
 void set_game_time(uint32_t new_time) {
-    time_left = new_time;
+    game_time_left = new_time;
 }
 
 uint32_t get_game_time() {
-    return time_left;
+    return game_time_left;
 }
 
 void set_module_time(uint32_t new_time) {
-    time_left = new_time;
+    module_time_left = new_time;
 }
 
 uint32_t get_module_time() {
-    return time_left;
+    return module_time_left;
 }
 
 static void game_timer_task(void *arg)
diff --git a/main/drivers/game_timer.h b/main/drivers/game_timer.h
index a5eb25d..5729772 100644
--- a/main/drivers/game_timer.h
+++ b/main/drivers/game_timer.h
@@ -2,7 +2,7 @@
 #define GAME_TIMER_H
 
 #include "freertos/FreeRTOS.h"
-#include "sseg.hpp"
+#include "sseg.h"
 
 /// Initializes the game and module timers.
 void init_game_module_timer(void);
diff --git a/main/drivers/leds.cpp b/main/drivers/leds.cpp
index b0bc4cb..1709dc0 100644
--- a/main/drivers/leds.cpp
+++ b/main/drivers/leds.cpp
@@ -1,5 +1,7 @@
 #include "leds.h"
 
+
+
 #define PIXEL_COUNT 21
 #define NEOPIXEL_PIN GPIO_NUM_7
 
diff --git a/main/drivers/sd.cpp b/main/drivers/sd.cpp
index 2e51882..806c885 100644
--- a/main/drivers/sd.cpp
+++ b/main/drivers/sd.cpp
@@ -1,5 +1,10 @@
 #include "sd.h"
 
+sdmmc_card_t *card;
+
+static const char* mount_point = MOUNT_POINT;
+static const char* TAG = "sd";
+
 void init_sd() {
     esp_err_t ret;
 
@@ -13,14 +18,14 @@ void init_sd() {
         .disk_status_check_enable = false,
     };
 
-    ESP_LOGI(SD_TAG, "Initializing SD card");
+    ESP_LOGI(TAG, "Initializing SD card");
 
     // Use settings defined above to initialize SD card and mount FAT filesystem.
     // Note: esp_vfs_fat_sdmmc/sdspi_mount is all-in-one convenience functions.
     // Please check its source code and implement error recovery when developing
     // production applications.
 
-    ESP_LOGI(SD_TAG, "Using SDMMC peripheral");
+    ESP_LOGI(TAG, "Using SDMMC peripheral");
     sdmmc_host_t host = SDMMC_HOST_DEFAULT();
 
     // This initializes the slot without card detect (CD) and write protect (WP) signals.
@@ -44,20 +49,20 @@ void init_sd() {
     // connected on the bus. This is for debug / example purpose only.
     slot_config.flags |= SDMMC_SLOT_FLAG_INTERNAL_PULLUP;
 
-    ESP_LOGI(SD_TAG, "Mounting filesystem");
+    ESP_LOGI(TAG, "Mounting filesystem");
     ret = esp_vfs_fat_sdmmc_mount(mount_point, &host, &slot_config, &mount_config, &card);
 
     if (ret != ESP_OK) {
         if (ret == ESP_FAIL) {
-            ESP_LOGE(SD_TAG, "Failed to mount filesystem. "
+            ESP_LOGE(TAG, "Failed to mount filesystem. "
                      "If you want the card to be formatted, set the EXAMPLE_FORMAT_IF_MOUNT_FAILED menuconfig option.");
         } else {
-            ESP_LOGE(SD_TAG, "Failed to initialize the card (%s). "
+            ESP_LOGE(TAG, "Failed to initialize the card (%s). "
                      "Make sure SD card lines have pull-up resistors in place.", esp_err_to_name(ret));
         }
         return;
     }
-    ESP_LOGI(SD_TAG, "Filesystem mounted");
+    ESP_LOGI(TAG, "Filesystem mounted");
 
     // Card has been initialized, print its properties
     sdmmc_card_print_info(stdout, card);
@@ -65,5 +70,5 @@ void init_sd() {
 
 void deinit_sd() {
     esp_vfs_fat_sdcard_unmount(mount_point, card);
-    ESP_LOGI(SD_TAG, "Card unmounted");
+    ESP_LOGI(TAG, "Card unmounted");
 }
diff --git a/main/drivers/sd.h b/main/drivers/sd.h
index 8ddb57d..35b38d5 100644
--- a/main/drivers/sd.h
+++ b/main/drivers/sd.h
@@ -10,9 +10,7 @@
 
 #define MOUNT_POINT "/sdcard"
 
-const char mount_point[] = MOUNT_POINT;
-
-sdmmc_card_t *card;
+extern sdmmc_card_t *card;
 
 #define SD_PIN_CLK GPIO_NUM_48
 #define SD_PIN_CMD GPIO_NUM_45
diff --git a/main/drivers/speaker.h b/main/drivers/speaker.h
index 8c3b1c3..47decb1 100644
--- a/main/drivers/speaker.h
+++ b/main/drivers/speaker.h
@@ -9,7 +9,7 @@
 #include "driver/gpio.h"
 #include "esp_check.h"
 #include "sdkconfig.h"
-#include "sd.hpp"
+#include "sd.h"
 
 #define SPEAKER_PIN_BCLK  GPIO_NUM_46
 #define SPEAKER_PIN_WS    GPIO_NUM_9
@@ -17,12 +17,8 @@
 #define SAMPLE_RATE 44100
 #define AUDIO_BUFFER 2048
 
-static i2s_chan_handle_t tx_chan;
-
-static const char *SPEAKER_TAG = "speaker_driver";
-
 esp_err_t play_raw(const char *fp);
-void init_speaker(void)
+void init_speaker(void);
 void play_example();
 
 #endif /* SPEAKER_H */
\ No newline at end of file
diff --git a/main/drivers/sseg.cpp b/main/drivers/sseg.cpp
index 3f11807..64fc154 100644
--- a/main/drivers/sseg.cpp
+++ b/main/drivers/sseg.cpp
@@ -1,5 +1,7 @@
 #include "sseg.h"
 
+TM1640* sseg = nullptr;
+
 static const char *TAG = "sseg_driver";
 
 void init_sseg() {
diff --git a/main/drivers/sseg.h b/main/drivers/sseg.h
index c4e9c39..53afd78 100644
--- a/main/drivers/sseg.h
+++ b/main/drivers/sseg.h
@@ -7,7 +7,7 @@
 #define SSEG_PIN_DATA GPIO_NUM_10
 #define SSEG_PIN_CLK  GPIO_NUM_11
 
-TM1640* sseg = nullptr;
+extern TM1640* sseg;
 
 /// Initializes the seven segment driver
 void init_sseg();
diff --git a/main/main.cpp b/main/main.cpp
index 73d0aa4..9c7cc03 100755
--- a/main/main.cpp
+++ b/main/main.cpp
@@ -7,10 +7,10 @@
 #include "drivers/tft.hpp"
 #include "drivers/wires.h"
 #include "drivers/bottom_half.h"
-#include "drivers/sd.hpp"
-#include "drivers/game_timer.hpp"
-#include "drivers/speaker.hpp"
-#include "drivers/char_lcd.hpp"
+#include "drivers/sd.h"
+#include "drivers/game_timer.h"
+#include "drivers/speaker.h"
+#include "drivers/char_lcd.h"
 #include "esp_rom_gpio.h"
 
 #include "steps/step0.hpp"
@@ -25,7 +25,6 @@
 #define WIRES_REG_WIRES
 
 static const char *TAG = "main";
-static void relay_task(void *arg);
 
 extern "C" void app_main(void) {
     printf("app_main\n");
@@ -34,7 +33,7 @@ extern "C" void app_main(void) {
     init_tft();
     init_speaker();
     init_sseg();
-    init_game_timer();
+    init_game_module_timer();
     init_wires();
 
     init_bottom_half();
@@ -42,7 +41,7 @@ extern "C" void app_main(void) {
 
     step0();
     set_game_time(30000);
-    start_timer();
+    start_game_timer();
     step1();
     step2();
     step3();
@@ -50,7 +49,7 @@ extern "C" void app_main(void) {
     step5();
     step6();
 
-    stop_timer();
+    stop_game_timer();
     ESP_LOGI(TAG, "Bomb has been diffused. Counter-Terrorists win.");
     ESP_ERROR_CHECK_WITHOUT_ABORT(play_raw("/sdcard/diffused.pcm"));
 
diff --git a/main/steps/setup_wires.hpp b/main/steps/setup_wires.hpp
index e215431..7cb5a95 100644
--- a/main/steps/setup_wires.hpp
+++ b/main/steps/setup_wires.hpp
@@ -2,7 +2,7 @@
 #define SETUP_WIRES_HPP
 
 #include "../drivers/bottom_half.h"
-#include "../drivers/char_lcd.hpp"
+#include "../drivers/char_lcd.h"
 #include "wires_puzzle.h"
 #include <esp_log.h>
 
diff --git a/main/steps/step0.hpp b/main/steps/step0.hpp
index 8ac1e9d..c64fee8 100644
--- a/main/steps/step0.hpp
+++ b/main/steps/step0.hpp
@@ -2,7 +2,7 @@
 #define STEP_0_HPP
 
 #include "../drivers/bottom_half.h"
-#include "../drivers/char_lcd.hpp"
+#include "../drivers/char_lcd.h"
 #include "../drivers/wires.h"
 #include "setup_wires.hpp"