EXTI interrupt abstraction feature complete

CMakeLists.txt

@@ -34,6 +34,9 @@ set(PROJECT_INCLUDE_DIRECTORIES
         SHAL/Include/Peripheral/Timer/Reg
         SHAL/Include/Peripheral/GPIO
         SHAL/Include/Peripheral/GPIO/Reg
+        SHAL/Include/Peripheral/UART
+        SHAL/Include/Peripheral/UART/Reg
+        SHAL/Include/Peripheral/EXT/
         ${CMAKE_CURRENT_SOURCE_DIR}/SHAL/Include
 )
 

Drivers/CMSIS/Device/ST/STM32F0xx/Include/system_stm32f0xx.h

@@ -47,11 +47,6 @@
   */
   /* This variable is updated in three ways:
       1) by calling CMSIS function SystemCoreClockUpdate()
-      3) by calling HAL API function HAL_RCC_GetHCLKFreq()
-      3) by calling HAL API function HAL_RCC_ClockConfig()
-         Note: If you use this function to configure the system clock; then there
-               is no need to call the 2 first functions listed above, since SystemCoreClock
-               variable is updated automatically.
   */
 extern uint32_t SystemCoreClock;          /*!< System Clock Frequency (Core Clock) */
 extern const uint8_t AHBPrescTable[16];   /*!< AHB prescalers table values */

SHAL/Include/Core/SHAL_CORE.h

@@ -13,20 +13,9 @@
 
 //Universal structs and defines ---------------------------
 
-struct SHAL_Peripheral {
-    void* registers;
-    unsigned long global_offset;
-};
 
-struct SHAL_Peripheral_Register {
-    volatile uint32_t* reg;
-    unsigned long offset;
-};
 
-struct SHAL_EXTIO_Register{
+
-    volatile uint32_t* EXT_ICR;
-    unsigned long mask;
-};
 
 //---------------------------------------------------------
 
@@ -55,7 +44,6 @@ struct SHAL_EXTIO_Register{
 #include "stm32f071xb.h"
 #elif defined(STM32F072xB)
 #include "stm32f072xb.h"
-#include "SHAL_TIM_REG_F072xB.h"
 #elif defined(STM32F078xx)
 #include "stm32f078xx.h"
 #elif defined(STM32F091xC)

SHAL/Include/Peripheral/EXT/SHAL_EXTI_CALLBACK.h

@@ -0,0 +1,41 @@
+/**
+  ******************************************************************************
+  * @file    SHAL_TIM.h
+  * @author  Luca Lizaranzu
+  * @brief   Callbacks for external interrupts
+  ******************************************************************************
+  */
+
+#ifndef SHAL_EXTI_CALLBACK_H
+#define SHAL_EXTI_CALLBACK_H
+
+#include "SHAL_CORE.h"
+#include "SHAL_GPIO_REG.h"
+
+#define DEFINE_EXTI_IRQ(EXTI_Channel)                           \
+extern "C" void EXTI##EXTI_Channel##_IRQHandler(void) {         \
+    if (EXTI->PR & (1 << EXTI_Channel)) {                   \
+        EXTI->PR |= (1 << EXTI_Channel); /*clear flag */    \
+        auto cb = EXTI_callbacks[EXTI_Channel];                 \
+        if (cb) cb();                                           \
+    };                                                          \
+};
+
+#define DEFINE_MULTI_EXTI_IRQ(EXTI_Channel_Min, EXTI_Channel_Max)                   \
+extern "C" void EXTI##EXTI_Channel_Min##_##EXTI_Channel_Max##_IRQHandler(void) {    \
+    for(uint8_t line = EXTI_Channel_Min; line <= EXTI_Channel_Max; line++){         \
+        if (EXTI->PR & (1 << line)) {                                   \
+            EXTI->PR |= (1 << line); /*clear flag */                    \
+            auto cb = EXTI_callbacks[line];                                         \
+            if (cb) cb();                                                           \
+        };                                                                          \
+    }                                                                               \
+};
+
+typedef void (*EXTICallback)(); //Typedef for callback function
+
+[[maybe_unused]] static EXTICallback EXTI_callbacks[NUM_EXTI_LINES] = {nullptr}; //Timer IRQ Callback table
+
+void registerEXTICallback(GPIO_Key key, EXTICallback callback);
+
+#endif //SHAL_EXTI_CALLBACK_H

SHAL/Include/Peripheral/GPIO/Reg/SHAL_GPIO_REG.h

@@ -0,0 +1,47 @@
+//
+// Created by Luca on 9/6/2025.
+//
+
+#ifndef SHAL_GPIO_REG_H
+#define SHAL_GPIO_REG_H
+
+#if defined(STM32F030x6)
+#include "stm32f030x6.h"
+#elif defined(STM32F030x8)
+#include "stm32f030x8.h"
+#elif defined(STM32F031x6)
+#include "stm32f031x6.h"
+#elif defined(STM32F038xx)
+#include "stm32f038xx.h"
+#elif defined(STM32F042x6)
+#include "stm32f042x6.h"
+#elif defined(STM32F048xx)
+#include "stm32f048xx.h"
+#elif defined(STM32F051x8)
+#include "stm32f051x8.h"
+#elif defined(STM32F058xx)
+#include "stm32f058xx.h"
+#elif defined(STM32F070x6)
+#include "stm32f070x6.h"
+#elif defined(STM32F070xB)
+#include "stm32f070xb.h"
+#elif defined(STM32F071xB)
+#include "stm32f071xb.h"
+#elif defined(STM32F072xB)
+#include "SHAL_GPIO_REG_F072xB.h"
+#elif defined(STM32F078xx)
+#include "stm32f078xx.h"
+#elif defined(STM32F091xC)
+  #include "stm32f091xc.h"
+#elif defined(STM32F098xx)
+  #include "stm32f098xx.h"
+#elif defined(STM32F030xC)
+  #include "stm32f030xc.h"
+#else
+ #error "Please select first the target STM32F0xx device used in your application (in stm32f0xx.h file)"
+#endif
+
+
+
+
+#endif //SHMINGO_HAL_SHAL_GPIO_REG_H

SHAL/Include/Peripheral/GPIO/Reg/SHAL_GPIO_REG_F072xB.h

@@ -2,16 +2,17 @@
 // Created by Luca on 8/29/2025.
 //
 
-#ifndef SHMINGO_HAL_SHAL_GPIO_REG_F072XB_H
+#ifndef SHAL_GPIO_REG_F072XB_H
-#define SHMINGO_HAL_SHAL_GPIO_REG_F072XB_H
+#define SHAL_GPIO_REG_F072XB_H
 
 #include <stm32f072xb.h>
 #include <cassert>
 
-#include "SHAL_CORE.h"
+#include "SHAL_GPIO_TYPES.h"
 
 #define AVAILABLE_PORTS 3
 #define PINS_PER_PORT 16
+#define NUM_EXTI_LINES 16
 
 #define AVAILABLE_GPIO \
     X(A0) X(A1) X(A2) X(A3) X(A4) X(A5) X(A6) X(A7) X(A8) X(A9) X(A10) X(A11) X(A12) X(A13) X(A14) X(A15) \
@@ -29,7 +30,8 @@ enum class GPIO_Key : uint8_t {
 };
 
 
-constexpr SHAL_Peripheral getGPIORegister(const GPIO_Key g){
+
+constexpr SHAL_GPIO_Peripheral getGPIORegister(const GPIO_Key g){
     switch(g) {
         case GPIO_Key::A0: return {GPIOA,0};
         case GPIO_Key::A1: return {GPIOA,1};
@@ -82,66 +84,66 @@ constexpr SHAL_Peripheral getGPIORegister(const GPIO_Key g){
         case GPIO_Key::INVALID:
         case GPIO_Key::NUM_GPIO:
             assert(false);
-            return SHAL_Peripheral(nullptr,0); //Unreachable
+            return SHAL_GPIO_Peripheral(nullptr,0); //Unreachable
     }
     __builtin_unreachable();
 }
 
 constexpr SHAL_EXTIO_Register getGPIOEXTICR(const GPIO_Key g){
     switch(g) {
-        case GPIO_Key::A0: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI0_PA};
+        case GPIO_Key::A0: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI0_PA,EXTI0_1_IRQn};
-        case GPIO_Key::A1: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI1_PA};
+        case GPIO_Key::A1: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI1_PA,EXTI0_1_IRQn};
-        case GPIO_Key::A2: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI2_PA};
+        case GPIO_Key::A2: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI2_PA,EXTI2_3_IRQn};
-        case GPIO_Key::A3: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI3_PA};
+        case GPIO_Key::A3: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI3_PA,EXTI2_3_IRQn};
-        case GPIO_Key::A4: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI4_PA};
+        case GPIO_Key::A4: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI4_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A5: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI5_PA};
+        case GPIO_Key::A5: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI5_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A6: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI6_PA};
+        case GPIO_Key::A6: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI6_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A7: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI7_PA};
+        case GPIO_Key::A7: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI7_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A8: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI8_PA};
+        case GPIO_Key::A8: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI8_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A9: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI9_PA};
+        case GPIO_Key::A9: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI9_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A10: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI10_PA};
+        case GPIO_Key::A10: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI10_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A11: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI11_PA};
+        case GPIO_Key::A11: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI11_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A12: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI12_PA};
+        case GPIO_Key::A12: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI12_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A13: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI13_PA};
+        case GPIO_Key::A13: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI13_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A14: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI14_PA};
+        case GPIO_Key::A14: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI14_PA,EXTI4_15_IRQn};
-        case GPIO_Key::A15: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI15_PA};
+        case GPIO_Key::A15: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI15_PA,EXTI4_15_IRQn};
-        case GPIO_Key::B0: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI0_PB};
+        case GPIO_Key::B0: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI0_PB,EXTI0_1_IRQn};
-        case GPIO_Key::B1: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI1_PB};
+        case GPIO_Key::B1: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI1_PB,EXTI0_1_IRQn};
-        case GPIO_Key::B2: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI2_PB};
+        case GPIO_Key::B2: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI2_PB,EXTI2_3_IRQn};
-        case GPIO_Key::B3: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI3_PB};
+        case GPIO_Key::B3: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI3_PB,EXTI2_3_IRQn};
-        case GPIO_Key::B4: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI4_PB};
+        case GPIO_Key::B4: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI4_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B5: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI5_PB};
+        case GPIO_Key::B5: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI5_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B6: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI6_PB};
+        case GPIO_Key::B6: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI6_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B7: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI7_PB};
+        case GPIO_Key::B7: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI7_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B8: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI8_PB};
+        case GPIO_Key::B8: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI8_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B9: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI9_PB};
+        case GPIO_Key::B9: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI9_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B10: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI10_PB};
+        case GPIO_Key::B10: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI10_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B11: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI11_PB};
+        case GPIO_Key::B11: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI11_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B12: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI12_PB};
+        case GPIO_Key::B12: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI12_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B13: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI13_PB};
+        case GPIO_Key::B13: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI13_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B14: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI14_PB};
+        case GPIO_Key::B14: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI14_PB,EXTI4_15_IRQn};
-        case GPIO_Key::B15: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI15_PB};
+        case GPIO_Key::B15: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI15_PB,EXTI4_15_IRQn};
-        case GPIO_Key::C0: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI0_PC};
+        case GPIO_Key::C0: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI0_PC,EXTI0_1_IRQn};
-        case GPIO_Key::C1: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI1_PC};
+        case GPIO_Key::C1: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI1_PC,EXTI0_1_IRQn};
-        case GPIO_Key::C2: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI2_PC};
+        case GPIO_Key::C2: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI2_PC,EXTI2_3_IRQn};
-        case GPIO_Key::C3: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI3_PC};
+        case GPIO_Key::C3: return {&SYSCFG->EXTICR[0],SYSCFG_EXTICR1_EXTI3_PC,EXTI2_3_IRQn};
-        case GPIO_Key::C4: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI4_PC};
+        case GPIO_Key::C4: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI4_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C5: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI5_PC};
+        case GPIO_Key::C5: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI5_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C6: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI6_PC};
+        case GPIO_Key::C6: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI6_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C7: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI7_PC};
+        case GPIO_Key::C7: return {&SYSCFG->EXTICR[1],SYSCFG_EXTICR2_EXTI7_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C8: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI8_PC};
+        case GPIO_Key::C8: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI8_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C9: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI9_PC};
+        case GPIO_Key::C9: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI9_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C10: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI10_PC};
+        case GPIO_Key::C10: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI10_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C11: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI11_PC};
+        case GPIO_Key::C11: return {&SYSCFG->EXTICR[2],SYSCFG_EXTICR3_EXTI11_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C12: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI12_PC};
+        case GPIO_Key::C12: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI12_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C13: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI13_PC};
+        case GPIO_Key::C13: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI13_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C14: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI14_PC};
+        case GPIO_Key::C14: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI14_PC,EXTI4_15_IRQn};
-        case GPIO_Key::C15: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI15_PC};
+        case GPIO_Key::C15: return {&SYSCFG->EXTICR[3],SYSCFG_EXTICR4_EXTI15_PC,EXTI4_15_IRQn};
 
         case GPIO_Key::INVALID:
         case GPIO_Key::NUM_GPIO:
             assert(false);
-            return SHAL_EXTIO_Register(nullptr,0); //Unreachable
+            return SHAL_EXTIO_Register(nullptr,0, EXTI4_15_IRQn); //Unreachable
     }
     __builtin_unreachable();
 }
@@ -207,7 +209,7 @@ constexpr SHAL_Peripheral_Register getGPIORCCEnable(const GPIO_Key g){
     __builtin_unreachable();
 }
 
-constexpr unsigned int getGPIOPortNumber(const GPIO_Key g){
+constexpr uint32_t getGPIOPortNumber(const GPIO_Key g){
     switch(g) {
         case GPIO_Key::A0:
         case GPIO_Key::A1:
@@ -268,4 +270,6 @@ constexpr unsigned int getGPIOPortNumber(const GPIO_Key g){
     __builtin_unreachable();
 }
 
+
+
 #endif //SHMINGO_HAL_SHAL_GPIO_REG_F072XB_H

SHAL/Include/Peripheral/GPIO/Reg/SHAL_GPIO_TYPES.h

@@ -0,0 +1,29 @@
+//
+// Created by Luca on 9/6/2025.
+//
+
+#ifndef SHAL_GPIO_TYPES_H
+#define SHAL_GPIO_TYPES_H
+
+#include "SHAL_CORE.h"
+
+
+struct SHAL_EXTIO_Register{
+    volatile uint32_t* EXT_ICR;
+    uint32_t mask;
+    IRQn_Type IRQN;
+};
+
+struct SHAL_GPIO_Peripheral {
+    GPIO_TypeDef * reg;
+    unsigned long global_offset;
+};
+
+struct SHAL_Peripheral_Register {
+    volatile uint32_t* reg;
+    unsigned long offset;
+};
+
+
+
+#endif //SHMINGO_HAL_SHAL_GPIO_TYPES_H

SHAL/Include/Peripheral/GPIO/SHAL_GPIO.h

@@ -2,13 +2,16 @@
 // Created by Luca on 8/29/2025.
 //
 
-#ifndef SHMINGO_HAL_SHAL_GPIO_H
+#ifndef SHAL_GPIO_H
-#define SHMINGO_HAL_SHAL_GPIO_H
+#define SHAL_GPIO_H
 
-#include "SHAL_CORE.h"
+#include "SHAL_GPIO_REG.h"
 
 #include <cassert>
-#include "SHAL_GPIO_REG_F072xB.h"
+
+#include "SHAL_EXTI_CALLBACK.h"
+
+
 
 enum class PinMode : uint8_t{
     INPUT_MODE,
@@ -17,15 +20,20 @@ enum class PinMode : uint8_t{
     ANALOG_MODE,
     INVALID
 };
-
 unsigned long getPinMode(PinMode mode);
 
+enum class TriggerMode : uint8_t{
+    RISING_EDGE,
+    FALLING_EDGE,
+    RISING_FALLING_EDGE
+};
+
 //Abstraction of GPIO registers
 class GPIO{
 
 public:
 
-    void toggle();
+    void toggle() volatile;
 
     //TODO replace stupid offset hack from APB
     void setHigh();
@@ -42,15 +50,21 @@ private:
 
 };
 
-
+//Init GPIO for normal use
 #define initGPIO(GPIO_KEY, PIN_MODE) GPIOManager::get(GPIO_KEY, PIN_MODE)
 
+//Init GPIO for use as an external interrupt
+#define useGPIOAsInterrupt(GPIO_KEY, Trigger_Mode, Callback) GPIOManager::getInterruptGPIO(GPIO_KEY, Trigger_Mode, Callback)
+
 //Manages instances of GPIO objects
 class GPIOManager{
 
 public:
 
     static GPIO& get(GPIO_Key, PinMode pinMode);
+
+    static void getInterruptGPIO(GPIO_Key key, TriggerMode mode, EXTICallback callback);
+
     GPIOManager() = delete;
 
 private:
@@ -59,4 +73,5 @@ inline static GPIO m_gpios[AVAILABLE_PORTS][PINS_PER_PORT] = {{}};
 
 };
 
+
 #endif //SHMINGO_HAL_SHAL_GPIO_H

SHAL/Include/Peripheral/Timer/Reg/SHAL_TIM_REG.h

@@ -0,0 +1,44 @@
+//
+// Created by Luca on 9/7/2025.
+//
+
+#ifndef SHMINGO_HAL_SHAL_TIM_REG_H
+#define SHMINGO_HAL_SHAL_TIM_REG_H
+
+#if defined(STM32F030x6)
+#include "stm32f030x6.h"
+#elif defined(STM32F030x8)
+#include "stm32f030x8.h"
+#elif defined(STM32F031x6)
+#include "stm32f031x6.h"
+#elif defined(STM32F038xx)
+#include "stm32f038xx.h"
+#elif defined(STM32F042x6)
+#include "stm32f042x6.h"
+#elif defined(STM32F048xx)
+#include "stm32f048xx.h"
+#elif defined(STM32F051x8)
+#include "stm32f051x8.h"
+#elif defined(STM32F058xx)
+#include "stm32f058xx.h"
+#elif defined(STM32F070x6)
+#include "stm32f070x6.h"
+#elif defined(STM32F070xB)
+#include "stm32f070xb.h"
+#elif defined(STM32F071xB)
+#include "stm32f071xb.h"
+#elif defined(STM32F072xB)
+#include "SHAL_TIM_REG_F072xB.h"
+#elif defined(STM32F078xx)
+#include "stm32f078xx.h"
+#elif defined(STM32F091xC)
+  #include "stm32f091xc.h"
+#elif defined(STM32F098xx)
+  #include "stm32f098xx.h"
+#elif defined(STM32F030xC)
+  #include "stm32f030xc.h"
+#else
+ #error "Please select first the target STM32F0xx device used in your application (in stm32f0xx.h file)"
+#endif
+
+#endif //SHMINGO_HAL_SHAL_TIM_REG_H

SHAL/Include/Peripheral/Timer/Reg/SHAL_TIM_REG_F072xB.h

@@ -13,6 +13,7 @@
 #include <stm32f072xb.h>
 
 #include "SHAL_CORE.h"
+#include "SHAL_TIM_TYPES.h"
 
 enum class Timer_Key : uint8_t { //For STM32F072
     S_TIM1,
@@ -30,7 +31,7 @@ enum class Timer_Key : uint8_t { //For STM32F072
 
 
 //Get TIMER_KEY peripheral struct including bus register, enable mask, TIMER_KEY mask
-constexpr SHAL_Peripheral_Register getTimerRCC(Timer_Key t) {
+constexpr TIM_RCC_Enable getTimerRCC(Timer_Key t) {
     switch(t) {
         case Timer_Key::S_TIM1:  return {&RCC->APB2ENR, RCC_APB2ENR_TIM1EN_Pos};
         case Timer_Key::S_TIM2:  return {&RCC->APB1ENR, RCC_APB1ENR_TIM2EN_Pos};

SHAL/Include/Peripheral/Timer/Reg/SHAL_TIM_TYPES.h

@@ -0,0 +1,15 @@
+//
+// Created by Luca on 9/7/2025.
+//
+
+#ifndef SHMINGO_HAL_SHAL_TIM_TYPES_H
+#define SHMINGO_HAL_SHAL_TIM_TYPES_H
+
+#include "SHAL_CORE.h"
+
+struct TIM_RCC_Enable{
+    volatile uint32_t* busEnableReg;
+    uint32_t offset;
+};
+
+#endif //SHMINGO_HAL_SHAL_TIM_TYPES_H

SHAL/Include/Peripheral/Timer/SHAL_TIM_CALLBACK.h

@@ -7,10 +7,11 @@
   ******************************************************************************
   */
 
-#ifndef SHMINGO_HAL_SHAL_TIM_CALLBACK_H
+#ifndef SHAL_TIM_CALLBACK_H
-#define SHMINGO_HAL_SHAL_TIM_CALLBACK_H
+#define SHAL_TIM_CALLBACK_H
 
-#include "SHAL/Include/Core/SHAL_CORE.h"
+#include "SHAL_CORE.h"
+#include "SHAL_TIM_REG.h"
 
 #define DEFINE_TIMER_IRQ(key, irq_handler)                \
 extern "C" void irq_handler(void) {                       \

SHAL/Include/Peripheral/UART/Reg/SHAL_UART_REG.h

@@ -0,0 +1,50 @@
+//
+// Created by Luca on 9/7/2025.
+//
+
+#ifndef SHAL_UART_REG_H
+#define SHAL_UART_REG_H
+
+//
+// Created by Luca on 9/6/2025.
+//
+
+
+#if defined(STM32F030x6)
+#include "stm32f030x6.h"
+#elif defined(STM32F030x8)
+#include "stm32f030x8.h"
+#elif defined(STM32F031x6)
+#include "stm32f031x6.h"
+#elif defined(STM32F038xx)
+#include "stm32f038xx.h"
+#elif defined(STM32F042x6)
+#include "stm32f042x6.h"
+#elif defined(STM32F048xx)
+#include "stm32f048xx.h"
+#elif defined(STM32F051x8)
+#include "stm32f051x8.h"
+#elif defined(STM32F058xx)
+#include "stm32f058xx.h"
+#elif defined(STM32F070x6)
+#include "stm32f070x6.h"
+#elif defined(STM32F070xB)
+#include "stm32f070xb.h"
+#elif defined(STM32F071xB)
+#include "stm32f071xb.h"
+#elif defined(STM32F072xB)
+#include "SHAL_UART_REG_F072xB.h"
+#elif defined(STM32F078xx)
+#include "stm32f078xx.h"
+#elif defined(STM32F091xC)
+  #include "stm32f091xc.h"
+#elif defined(STM32F098xx)
+  #include "stm32f098xx.h"
+#elif defined(STM32F030xC)
+  #include "stm32f030xc.h"
+#else
+ #error "Please select first the target STM32F0xx device used in your application (in stm32f0xx.h file)"
+#endif
+
+
+#endif //SHMINGO_HAL_SHAL_UART_REG_H

SHAL/Include/Peripheral/UART/Reg/SHAL_UART_REG_F072xB.h

@@ -0,0 +1,118 @@
+//
+// Created by Luca on 9/7/2025.
+//
+
+#ifndef SHAL_UART_REG_F072XB_H
+#define SHAL_UART_REG_F072XB_H
+
+#include <stm32f072xb.h>
+#include <cassert>
+
+#include "SHAL_UART_TYPES.h"
+
+#define NUM_USART_LINES 4
+
+//Valid usart Tx and Rx pairings for STM32F072
+enum class UART_Pair : uint8_t{
+    //UART1
+    Tx1A9_Rx1A10,
+    Tx1B6_Rx1B7,
+
+    //UART2
+    Tx2A2_Rx2A3,
+    Tx2A14_Rx2A15,
+
+    //UART3
+    Tx3B10_Rx3B11,
+    Tx3C4_Rx3C5,
+    Tx3C10_Rx3C11,
+
+    //UART4
+    Tx4A0_Rx4A1,
+    Tx4C10_Rx4C11,
+
+    NUM_PAIRS,
+    INVALID
+};
+
+
+constexpr SHAL_UART_Pair getUARTPair(const UART_Pair pair){
+    switch(pair){
+        case UART_Pair::Tx1A9_Rx1A10: return {USART1,GPIO_Key::A9,GPIO_Key::A10,AF_Mask::AF1,AF_Mask::AF1};
+        case UART_Pair::Tx1B6_Rx1B7: return {USART1,GPIO_Key::B6,GPIO_Key::B7,AF_Mask::AF0,AF_Mask::AF0};
+        case UART_Pair::Tx2A2_Rx2A3: return {USART2,GPIO_Key::A2,GPIO_Key::A3,AF_Mask::AF1,AF_Mask::AF1};
+        case UART_Pair::Tx2A14_Rx2A15: return {USART2,GPIO_Key::A14,GPIO_Key::A15,AF_Mask::AF1,AF_Mask::AF1};
+        case UART_Pair::Tx3B10_Rx3B11: return {USART3,GPIO_Key::B10,GPIO_Key::B11,AF_Mask::AF4,AF_Mask::AF4};
+        case UART_Pair::Tx3C4_Rx3C5: return {USART3,GPIO_Key::C4,GPIO_Key::C5,AF_Mask::AF1,AF_Mask::AF1};
+        case UART_Pair::Tx3C10_Rx3C11: return {USART3,GPIO_Key::C10,GPIO_Key::C11,AF_Mask::AF1,AF_Mask::AF1};
+        case UART_Pair::Tx4A0_Rx4A1: return {USART4,GPIO_Key::A0,GPIO_Key::A1,AF_Mask::AF4,AF_Mask::AF4};
+        case UART_Pair::Tx4C10_Rx4C11: return {USART4,GPIO_Key::C10,GPIO_Key::C11,AF_Mask::AF0,AF_Mask::AF0};
+        case UART_Pair::NUM_PAIRS:
+        case UART_Pair::INVALID:
+            assert(false);
+            return {nullptr,GPIO_Key::INVALID,GPIO_Key::INVALID,AF_Mask::AF0,AF_Mask::AF0};
+    }
+    __builtin_unreachable();
+}
+
+constexpr uint8_t getUARTChannel(const UART_Pair pair){
+    switch(pair){
+        case UART_Pair::Tx1A9_Rx1A10:
+        case UART_Pair::Tx1B6_Rx1B7:
+            return 0;
+        case UART_Pair::Tx2A2_Rx2A3:
+        case UART_Pair::Tx2A14_Rx2A15:
+            return 1;
+        case UART_Pair::Tx3B10_Rx3B11:
+        case UART_Pair::Tx3C4_Rx3C5:
+        case UART_Pair::Tx3C10_Rx3C11:
+            return 2;
+        case UART_Pair::Tx4A0_Rx4A1:
+        case UART_Pair::Tx4C10_Rx4C11:
+            return 3;
+        case UART_Pair::NUM_PAIRS:
+        case UART_Pair::INVALID:
+            assert(false);
+            return 0;
+    }
+    __builtin_unreachable();
+}
+
+constexpr SHAL_UART_ENABLE_REG getUARTEnableReg(const UART_Pair pair){
+    switch(pair){
+        case UART_Pair::Tx1A9_Rx1A10:
+        case UART_Pair::Tx1B6_Rx1B7:
+            return {&RCC->APB2ENR,RCC_APB2ENR_USART1EN};
+        case UART_Pair::Tx2A2_Rx2A3:
+        case UART_Pair::Tx2A14_Rx2A15:
+            return {&RCC->APB1ENR,RCC_APB1ENR_USART2EN};
+        case UART_Pair::Tx3B10_Rx3B11:
+        case UART_Pair::Tx3C4_Rx3C5:
+        case UART_Pair::Tx3C10_Rx3C11:
+            return {&RCC->APB1ENR,RCC_APB1ENR_USART3EN};
+        case UART_Pair::Tx4A0_Rx4A1:
+        case UART_Pair::Tx4C10_Rx4C11:
+            return {&RCC->APB1ENR,RCC_APB1ENR_USART4EN};
+        case UART_Pair::NUM_PAIRS:
+        case UART_Pair::INVALID:
+            assert(false);
+            return {nullptr, 0};
+    }
+    __builtin_unreachable();
+}
+
+constexpr uint32_t getAFMask(const AF_Mask mask){
+    switch(mask){
+        case AF_Mask::AF0: return 0x00;
+        case AF_Mask::AF1: return 0x01;
+        case AF_Mask::AF2: return 0x02;
+        case AF_Mask::AF3: return 0x03;
+        case AF_Mask::AF4: return 0x04;
+        case AF_Mask::AF5: return 0x05;
+        case AF_Mask::AF6: return 0x06;
+        case AF_Mask::AF7: return 0x07;
+    }
+    __builtin_unreachable();
+}
+
+#endif //SHMINGO_HAL_SHAL_UART_REG_F072XB_H

SHAL/Include/Peripheral/UART/Reg/SHAL_UART_TYPES.h

@@ -0,0 +1,37 @@
+//
+// Created by Luca on 9/7/2025.
+//
+
+#ifndef SHAL_UART_TYPES_H
+#define SHAL_UART_TYPES_H
+
+#include "SHAL_CORE.h"
+#include "SHAL_GPIO_REG.h"
+
+enum class AF_Mask : uint8_t{
+    AF0,
+    AF1,
+    AF2,
+    AF3,
+    AF4,
+    AF5,
+    AF6,
+    AF7
+};
+
+//Represents a pair of pins usable for USART Tx + Rx in combination, and their alternate function mapping
+struct SHAL_UART_Pair{
+
+    USART_TypeDef* USARTReg;
+    GPIO_Key TxKey;
+    GPIO_Key RxKey;
+    AF_Mask TxMask;
+    AF_Mask RxMask;
+};
+
+struct SHAL_UART_ENABLE_REG{
+    volatile uint32_t* reg;
+    uint32_t mask;
+};
+
+#endif //SHMINGO_HAL_SHAL_UART_TYPES_H

SHAL/Include/Peripheral/UART/SHAL_UART.h

@@ -0,0 +1,57 @@
+/**
+  ******************************************************************************
+  * @file    SHAL_TIM.h
+  * @author  Luca Lizaranzu
+  * @brief   Relating to UART and USART object abstractions
+  ******************************************************************************
+  */
+
+#ifndef SHMINGO_HAL_SHAL_UART_H
+#define SHMINGO_HAL_SHAL_UART_H
+
+#include "SHAL_UART_REG.h"
+
+class UART{
+
+    friend class UARTManager;
+public:
+
+    //begins Tx and Usart TODO either modify this function or add a new one that supports Rx
+    void begin(uint32_t baudRate) volatile;
+
+    //Sends a string
+    void sendString(const char* s) volatile;
+
+    //Sends a char
+    void sendChar(char c) volatile;
+
+private:
+
+    UART() = default; //Initializer for array
+
+    //Creates a UART based on a pair of two valid U(S)ART pins
+    explicit UART(UART_Pair pair);
+
+    UART_Pair m_UARTPair = UART_Pair::INVALID;
+
+};
+
+
+#define getUART(uart_pair) UARTManager::get(uart_pair)
+
+class UARTManager{
+
+public:
+
+    static UART& get(UART_Pair pair);
+
+
+    UARTManager() = delete;
+
+private:
+
+    inline static UART m_UARTs[NUM_USART_LINES] = {};
+
+};
+
+#endif //SHMINGO_HAL_SHAL_UART_H

SHAL/Include/SHAL.h

@@ -10,5 +10,6 @@
 
 #include "SHAL_TIM.h"
 #include "SHAL_GPIO.h"
+#include "SHAL_UART.h"
 
 #endif

SHAL/Src/EXT/SHAL_EXTI_CALLBACK.cpp

@@ -0,0 +1,40 @@
+//
+// Created by Luca on 9/3/2025.
+//
+
+#include "SHAL_EXTI_CALLBACK.h"
+
+#if defined(STM32F030x6)
+#elif defined(STM32F030x8)
+#elif defined(STM32F031x6)
+#elif defined(STM32F038xx)
+#elif defined(STM32F042x6)
+#elif defined(STM32F048xx)
+#elif defined(STM32F051x8)
+#elif defined(STM32F058xx)
+#elif defined(STM32F070x6)
+#elif defined(STM32F070xB)
+#elif defined(STM32F071xB)
+#elif defined(STM32F072xB)
+
+DEFINE_MULTI_EXTI_IRQ(0,1);
+DEFINE_MULTI_EXTI_IRQ(2,3);
+DEFINE_MULTI_EXTI_IRQ(4,15);
+
+#elif defined(STM32F078xx)
+#include "stm32f078xx.h"
+#elif defined(STM32F091xC)
+  #include "stm32f091xc.h"
+#elif defined(STM32F098xx)
+  #include "stm32f098xx.h"
+#elif defined(STM32F030xC)
+  #include "stm32f030xc.h"
+#else
+ #error "Please select first the target STM32F0xx device used in your application (in stm32f0xx.h file)"
+#endif
+
+
+//Link function to EXTI line
+void registerEXTICallback(GPIO_Key key, EXTICallback callback){
+    EXTI_callbacks[getGPIORegister(key).global_offset] = callback;
+}

SHAL/Src/Peripheral/GPIO/SHAL_GPIO.cpp

@@ -3,7 +3,7 @@
 //
 
 #include "SHAL_GPIO.h"
-
+#include "SHAL_EXTI_CALLBACK.h"
 
 unsigned long getPinMode(PinMode mode){
     switch(mode){
@@ -31,9 +31,9 @@ GPIO::GPIO() : m_GPIO_KEY(GPIO_Key::INVALID){
 
 GPIO::GPIO(GPIO_Key key, PinMode pinMode) : m_GPIO_KEY(key) {
 
-    SHAL_Peripheral gpioPeripheral = getGPIORegister(key);
+    SHAL_GPIO_Peripheral gpioPeripheral = getGPIORegister(key);
 
-    auto gpioRegister = static_cast<GPIO_TypeDef*>(gpioPeripheral.registers);
+    auto gpioRegister = gpioPeripheral.reg;
     unsigned long registerOffset = gpioPeripheral.global_offset;
 
     volatile unsigned long* gpioEnable = getGPIORCCEnable(key).reg;
@@ -47,17 +47,17 @@ GPIO::GPIO(GPIO_Key key, PinMode pinMode) : m_GPIO_KEY(key) {
 
 void GPIO::setLow() {
     auto gpioPeripheral = getGPIORegister(m_GPIO_KEY);
-    static_cast<GPIO_TypeDef*>(gpioPeripheral.registers)->ODR &= ~(1 << gpioPeripheral.global_offset);
+    gpioPeripheral.reg->ODR &= ~(1 << gpioPeripheral.global_offset);
 }
 
 void GPIO::setHigh() {
     auto gpioPeripheral = getGPIORegister(m_GPIO_KEY);
-    static_cast<GPIO_TypeDef*>(gpioPeripheral.registers)->ODR |= (1 << gpioPeripheral.global_offset);
+    gpioPeripheral.reg->ODR |= (1 << gpioPeripheral.global_offset);
 }
 
-void GPIO::toggle() {
+void GPIO::toggle() volatile {
-    auto gpioPeripheral = getGPIORegister(m_GPIO_KEY);
+    SHAL_GPIO_Peripheral gpioPeripheral = getGPIORegister(m_GPIO_KEY);
-    static_cast<GPIO_TypeDef*>(gpioPeripheral.registers)->ODR ^= (1 << gpioPeripheral.global_offset);
+    gpioPeripheral.reg->ODR ^= (1 << gpioPeripheral.global_offset);
 }
 
 
@@ -73,3 +73,46 @@ GPIO& GPIOManager::get(GPIO_Key key, PinMode pinMode) {
 
     return m_gpios[gpioPort][gpioPin];
 }
+
+void GPIOManager::getInterruptGPIO(GPIO_Key key, TriggerMode triggerMode, EXTICallback callback) {
+
+    uint32_t gpioPort = getGPIOPortNumber(key);
+    uint32_t gpioPin = getGPIORegister(key).global_offset; //Use existing structs to get offset
+
+    if (m_gpios[gpioPort][gpioPin].m_GPIO_KEY == GPIO_Key::INVALID){
+        m_gpios[gpioPort][gpioPin] = GPIO(key,PinMode::INPUT_MODE); //Hardcode input mode for interrupt
+    }
+
+    RCC->APB2ENR |= RCC_APB2ENR_SYSCFGCOMPEN; //Enable EXT, TODO check if this is different across STM32 models
+    NVIC_EnableIRQ(getGPIOEXTICR(key).IRQN); //Enable IRQN for pin
+    EXTI->IMR |= (1 << gpioPin); //Enable correct EXTI line
+
+    SHAL_EXTIO_Register EXTILineEnable = getGPIOEXTICR(key);
+    *EXTILineEnable.EXT_ICR |= EXTILineEnable.mask; //Set bits to enable correct port on correct line TODO Find way to clear bits before
+
+
+    uint32_t rising_mask = 0x00;
+    uint32_t falling_mask = 0x00;
+
+    //Set rising and falling edge triggers based on pin offset (enabled EXTI line)
+    switch(triggerMode){
+        case TriggerMode::RISING_EDGE:
+            rising_mask = 1 << gpioPin;
+            break;
+        case TriggerMode::FALLING_EDGE:
+            falling_mask = 1 << gpioPin;
+            break;
+        case TriggerMode::RISING_FALLING_EDGE:
+            falling_mask = 1 << gpioPin;
+            falling_mask = 1 << gpioPin;
+    }
+
+    //Set triggers
+    EXTI->RTSR |= rising_mask;
+    EXTI->FTSR |= falling_mask;
+
+    //Set callback
+    registerEXTICallback(key,callback);
+
+    __enable_irq(); //Enable IRQ just in case
+}

SHAL/Src/Peripheral/Timer/SHAL_TIM.cpp

@@ -6,8 +6,8 @@
 #include <cassert>
 
 Timer::Timer(Timer_Key t) : TIMER_KEY(t){
-    SHAL_Peripheral_Register rcc = getTimerRCC(TIMER_KEY);
+    TIM_RCC_Enable rcc = getTimerRCC(TIMER_KEY);
-    *rcc.reg |= (1 << rcc.offset);
+    *rcc.busEnableReg |= (1 << rcc.offset);
 }
 
 Timer::Timer() : TIMER_KEY(Timer_Key::S_TIM_INVALID){

SHAL/Src/Peripheral/UART/SHAL_UART.cpp

@@ -0,0 +1,82 @@
+/**
+  ******************************************************************************
+  * @file    SHAL_TIM.h
+  * @author  Luca Lizaranzu
+  * @brief   Related to USART and UART abstractions
+  ******************************************************************************
+  */
+
+
+#include "SHAL_UART.h"
+#include "SHAL_GPIO.h"
+
+UART::UART(const UART_Pair pair) : m_UARTPair(pair){
+    SHAL_UART_Pair uart_pair = getUARTPair(pair); //Get the UART_PAIR information to be initialized
+
+    //Get the GPIO pins for this UART setup
+    GPIO_Key Tx_Key = uart_pair.TxKey; //Tx pin
+    GPIO_Key Rx_Key = uart_pair.RxKey; //Rx pin
+
+    uint8_t Tx_Pin = getGPIORegister(Tx_Key).global_offset;
+    uint8_t Rx_Pin = getGPIORegister(Rx_Key).global_offset;
+
+    initGPIO(Tx_Key,PinMode::ALTERNATE_FUNCTION_MODE); //Initialize Tx GPIO with alternate function (initializes GPIO port as well)
+    initGPIO(Rx_Key,PinMode::ALTERNATE_FUNCTION_MODE); //Initialize Rx GPIO with alternate function
+
+    //Determine which AFR register (high or low) to write depending on pin
+    uint8_t TxAFR = Tx_Pin < 8 ? 0 : 1; //Use AFR[0] if pin < 8, AFR[1] if pin >= 8
+    uint8_t RxAFR = Rx_Pin < 8 ? 0 : 1;
+
+    /*Apply Alternate Function masks to the AFR registers for each GPIO to enable alternate functions
+     * The AFR register for GPIO_Typedef* is actually two registers - a low reg and high reg.
+     * The low reg handles pins 0-7, and the high reg handles 8-15.
+     * Each pin gets 4 bits in the register for AFR0 - AFR7. Hence 8 * 4 = 32 bits.
+     * Each AFR is a different function, look at the DATASHEET (not reference manual) to find these alternate function mappings
+     */
+    getGPIORegister(Tx_Key).reg->AFR[TxAFR] |= getAFMask(uart_pair.TxMask) << (4 * (Tx_Pin % 8));
+    getGPIORegister(Rx_Key).reg->AFR[RxAFR] |= getAFMask(uart_pair.RxMask) << (4 * (Rx_Pin % 8));
+
+    SHAL_UART_ENABLE_REG pairUARTEnable = getUARTEnableReg(pair); //Register and mask to enable the UART channel
+
+    *pairUARTEnable.reg |= pairUARTEnable.mask; //Enable UART line
+}
+
+void UART::begin(uint32_t baudRate) volatile {
+
+    USART_TypeDef* usart = getUARTPair(m_UARTPair).USARTReg;
+
+    usart->CR1 &= ~USART_CR1_UE; //Disable USART
+
+    usart->CR1 = 0; //Clear USART config
+
+    usart->CR1 = USART_CR1_TE | USART_CR1_RE; //Tx enable and Rx Enable
+
+    usart->BRR = 8000000 / baudRate; //MAKE SURE ANY FUNCTION THAT CHANGES CLOCK UPDATES THIS!
+
+    usart->CR1 |= USART_CR1_UE;
+
+}
+
+void UART::sendString(const char *s) volatile {
+    while (*s) sendChar(*s++); //Send chars while we haven't reached end of s
+}
+
+void UART::sendChar(char c) volatile {
+
+    USART_TypeDef* usart = getUARTPair(m_UARTPair).USARTReg;
+
+    while(!(usart->ISR & USART_ISR_TXE)); //Wait for usart to finish what it's doing
+
+    usart->TDR = c; //Send character
+}
+
+
+
+UART& UARTManager::get(UART_Pair pair) {
+
+    //Reassign if pair doesn't match
+    if(m_UARTs[getUARTChannel(pair)].m_UARTPair != pair) {
+        m_UARTs[getUARTChannel(pair)] = UART(pair);
+    }
+    return m_UARTs[getUARTChannel(pair)];
+}

SHAL/Src/System/system_stm32f0xx.c

@@ -91,11 +91,6 @@
   */
   /* This variable is updated in three ways:
       1) by calling CMSIS function SystemCoreClockUpdate()
-      2) by calling HAL API function HAL_RCC_GetHCLKFreq()
-      3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency
-         Note: If you use this function to configure the system clock; then there
-               is no need to call the 2 first functions listed above, since SystemCoreClock
-               variable is updated automatically.
   */
 uint32_t SystemCoreClock = 8000000;
 

SHAL/Src/main.cpp

@@ -2,14 +2,12 @@
 #include "stm32f0xx.h"
 
 
-GPIO* blueLED = nullptr;
+volatile GPIO* blueLED = nullptr;
-GPIO* greenLED = nullptr;
+volatile GPIO* greenLED = nullptr;
+volatile UART* uart2;
 
-extern "C" void EXTI0_1_IRQHandler(void) {
+void c3Interrupt(){
-    if (EXTI->PR & (1 << 0)) {   //Check pending flag
-        EXTI->PR |= (1 << 0);    //Clear it by writing 1
     greenLED->toggle();
-    }
 }
 
 void tim2Handler(){
@@ -17,7 +15,12 @@ void tim2Handler(){
 }
 
 int main() {
-    RCC->AHBENR |= RCC_AHBENR_GPIOBEN;
+
+    uart2 = &getUART(UART_Pair::Tx2A2_Rx2A3);
+
+    uart2->begin(115200);
+
+    useGPIOAsInterrupt(GPIO_Key::C3,TriggerMode::RISING_EDGE,c3Interrupt);
 
     Timer timer2 = getTimer(Timer_Key::S_TIM2);
 
@@ -29,18 +32,6 @@ int main() {
     timer2.setCallbackFunc(tim2Handler);
     timer2.start();
 
-    RCC->APB2ENR |= RCC_APB2ENR_SYSCFGCOMPEN; //Enable SYSCFG clock (needed for EXTI)
-
-    SYSCFG->EXTICR[0] &= ~SYSCFG_EXTICR1_EXTI0; //Clear EXTI0 mapping
-    SYSCFG->EXTICR[0] |= SYSCFG_EXTICR1_EXTI0_PB; //Map PA0 -> EXTI0
-
-    EXTI->IMR |= (1 << 0);   //Unmask EXTI0
-    EXTI->RTSR |= (1 << 0);  //Trigger on rising edge
-
-    NVIC_EnableIRQ(EXTI0_1_IRQn); //EXTI lines 0 and 1 share an IRQ vector
-
-    __enable_irq();
-
     while (true) {
     	__WFI();
     }