diff --git a/Drivers/CMSIS/Device/ST/STM32F0xx/Include/stm32f072xb.h b/Drivers/CMSIS/Device/ST/STM32F0xx/Include/stm32f072xb.h
index 849bade..6fb73b2 100644
--- a/Drivers/CMSIS/Device/ST/STM32F0xx/Include/stm32f072xb.h
+++ b/Drivers/CMSIS/Device/ST/STM32F0xx/Include/stm32f072xb.h
@@ -7875,7 +7875,7 @@ typedef struct
 #define RCC_AHBENR_GPIOEEN                       RCC_AHBENR_GPIOEEN_Msk        /*!< GPIOE clock enable */
 #define RCC_AHBENR_GPIOFEN_Pos                   (22U)
 #define RCC_AHBENR_GPIOFEN_Msk                   (0x1UL << RCC_AHBENR_GPIOFEN_Pos) /*!< 0x00400000 */
-#define RCC_AHBENR_GPIOFEN                       RCC_AHBENR_GPIOFEN_Msk        /*!< GPIOF clock enable */
+#define RCC_AHBENR_GPIOFEN                       RCC_AHBENR_GPIOFEN_Msk        /*!< GPIOF clock enable */RCC_AHBENR_GPIOAEN
 #define RCC_AHBENR_TSCEN_Pos                     (24U)
 #define RCC_AHBENR_TSCEN_Msk                     (0x1UL << RCC_AHBENR_TSCEN_Pos) /*!< 0x01000000 */
 #define RCC_AHBENR_TSCEN                         RCC_AHBENR_TSCEN_Msk          /*!< TS controller clock enable */
diff --git a/SHAL/Include/Peripheral/GPIO/SHAL_GPIO.h b/SHAL/Include/Peripheral/GPIO/SHAL_GPIO.h
index 29d0a62..eb5130f 100644
--- a/SHAL/Include/Peripheral/GPIO/SHAL_GPIO.h
+++ b/SHAL/Include/Peripheral/GPIO/SHAL_GPIO.h
@@ -18,19 +18,7 @@ enum class PinMode {
     INVALID
 };
 
-unsigned long getPinMode(PinMode mode){
-    switch(mode){
-        case PinMode::INPUT_MODE:
-            return 0b00;
-        case PinMode::OUTPUT_MODE:
-            return 0b01;
-        case PinMode::ALTERNATE_FUNCTION_MODE:
-            return 0b10;
-        case PinMode::ANALOG_MODE:
-            return 0b11;
-    }
-}
-
+unsigned long getPinMode(PinMode mode);
 
 //Abstraction of GPIO registers
 class GPIO{
@@ -65,12 +53,12 @@ class GPIOManager{
 
 public:
 
-    static GPIO& get(GPIO_Key, PinMode pinMode);
+    static GPIO* get(GPIO_Key, PinMode pinMode);
     GPIOManager() = delete;
 
 private:
 
-inline static GPIO m_gpios[AVAILABLE_PORTS][PINS_PER_PORT] = {};
+inline static GPIO* m_gpios[AVAILABLE_PORTS][PINS_PER_PORT] = {{nullptr}};
 
 };
 
diff --git a/SHAL/Src/Peripheral/GPIO/SHAL_GPIO.cpp b/SHAL/Src/Peripheral/GPIO/SHAL_GPIO.cpp
index c5c992a..9d1c3b6 100644
--- a/SHAL/Src/Peripheral/GPIO/SHAL_GPIO.cpp
+++ b/SHAL/Src/Peripheral/GPIO/SHAL_GPIO.cpp
@@ -4,6 +4,27 @@
 
 #include "SHAL_GPIO.h"
 
+
+unsigned long getPinMode(PinMode mode){
+    switch(mode){
+        case PinMode::INPUT_MODE:
+            return 0b00;
+        case PinMode::OUTPUT_MODE:
+            return 0b01;
+        case PinMode::ALTERNATE_FUNCTION_MODE:
+            return 0b10;
+        case PinMode::ANALOG_MODE:
+            return 0b11;
+        case PinMode::INVALID:
+            assert(false);
+            return 0;
+    }
+    __builtin_unreachable();
+}
+
+
+
+
 GPIO::GPIO(){
     //Do not initialize anything
 }
@@ -15,9 +36,10 @@ GPIO::GPIO(GPIO_Key key, PinMode pinMode) : m_GPIO_KEY(key),
     volatile unsigned long* gpioEnable = getGPIORCCEnable(key).reg;
     unsigned long gpioOffset = getGPIORCCEnable(key).offset;
 
-    *gpioEnable |= (1 << gpioOffset);
+    *gpioEnable |= (1 << gpioOffset); //Set enable flag
 
-    p_GPIORegister->MODER |= (getPinMode(pinMode) << (2 * m_offset));
+    p_GPIORegister->MODER &= ~(0b11 << (2 * m_offset)); //Clear any previous mode
+    p_GPIORegister->MODER |= (getPinMode(pinMode) << (2 * m_offset)); //Set mode based on pinmode bit structure
 }
 
 void GPIO::setLow() {
@@ -35,15 +57,15 @@ void GPIO::toggle() {
 
 
 
-GPIO &GPIOManager::get(GPIO_Key key, PinMode pinMode) {
+GPIO* GPIOManager::get(GPIO_Key key, PinMode pinMode) {
 
     unsigned int gpioPort = getGPIOPortNumber(key);
     unsigned long gpioPin = getGPIORegister(key).global_offset; //Use existing structs to get offset
 
-    GPIO curr = m_gpios[gpioPort][gpioPin];
+    GPIO curr = *m_gpios[gpioPort][gpioPin];
 
     if(curr.m_GPIO_KEY == GPIO_Key::INVALID || curr.m_pinMode != pinMode){
-        m_gpios[gpioPort][gpioPin] = GPIO(key,pinMode);
+        *m_gpios[gpioPort][gpioPin] = GPIO(key,pinMode);
     }
 
     return m_gpios[gpioPort][gpioPin];
diff --git a/SHAL/Src/main.cpp b/SHAL/Src/main.cpp
index 43a2e66..1ab354f 100644
--- a/SHAL/Src/main.cpp
+++ b/SHAL/Src/main.cpp
@@ -1,23 +1,28 @@
 #include "SHAL.h"
 #include "stm32f0xx.h"
 
+GPIO* blueLED;
+GPIO* greenLED;
+
 extern "C" void EXTI0_1_IRQHandler(void) {
     if (EXTI->PR & (1 << 0)) {   //Check pending flag
         EXTI->PR |= (1 << 0);    //Clear it by writing 1
-        GPIOA->ODR ^= (1 << 5);
+        blueLED->toggle();
     }
 }
 
 void tim2Handler(){
-    GPIOA->ODR ^= (1 << 4);
+    greenLED->toggle();
 }
 
 int main() {
-    RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
     RCC->AHBENR |= RCC_AHBENR_GPIOBEN;
 
     Timer timer2 = getTimer(Timer_Key::S_TIM2);
 
+    blueLED = initGPIO(GPIO_Key::A4, PinMode::OUTPUT_MODE);
+    greenLED = initGPIO(GPIO_Key::A5, PinMode::OUTPUT_MODE);
+
     timer2.setPrescaler(8000 - 1);
     timer2.setARR(1500 - 1);
     timer2.setCallbackFunc(tim2Handler);
@@ -26,12 +31,6 @@ int main() {
 
     RCC->APB2ENR |= RCC_APB2ENR_SYSCFGEN; //Enable SYSCFG clock (needed for EXTI)
 
-    GPIOA->MODER &= ~(0b11 << (4 * 2));
-    GPIOA->MODER |= (0b1 << (4 * 2));
-
-    GPIOA->MODER &= ~(0x3 << (5 * 2));
-    GPIOA->MODER |=  (0x1 << (5 * 2));
-
     GPIOB->MODER &= ~(0x3 << (0 * 2));
     GPIOB->MODER |=  (0x0 << (0 * 2));