diff --git a/Core/Inc/main.h b/Core/Inc/main.h
index 2d59677..a50506d 100644
--- a/Core/Inc/main.h
+++ b/Core/Inc/main.h
@@ -57,6 +57,9 @@ void Error_Handler(void);
 /* USER CODE END EFP */
 
 /* Private defines -----------------------------------------------------------*/
+#define BUT_BLUE_Pin GPIO_PIN_0
+#define BUT_BLUE_GPIO_Port GPIOA
+#define BUT_BLUE_EXTI_IRQn EXTI0_IRQn
 #define LED_GREEN_Pin GPIO_PIN_12
 #define LED_GREEN_GPIO_Port GPIOD
 
diff --git a/Core/Inc/stm32f4xx_it.h b/Core/Inc/stm32f4xx_it.h
index 1d9c427..2d849f8 100644
--- a/Core/Inc/stm32f4xx_it.h
+++ b/Core/Inc/stm32f4xx_it.h
@@ -53,6 +53,7 @@ void BusFault_Handler(void);
 void UsageFault_Handler(void);
 void DebugMon_Handler(void);
 void SysTick_Handler(void);
+void EXTI0_IRQHandler(void);
 void OTG_FS_IRQHandler(void);
 /* USER CODE BEGIN EFP */
 
diff --git a/Core/Src/gpio.c b/Core/Src/gpio.c
index 5fdaabd..6bcc006 100644
--- a/Core/Src/gpio.c
+++ b/Core/Src/gpio.c
@@ -53,6 +53,12 @@ void MX_GPIO_Init(void)
   /*Configure GPIO pin Output Level */
   HAL_GPIO_WritePin(LED_GREEN_GPIO_Port, LED_GREEN_Pin, GPIO_PIN_RESET);
 
+  /*Configure GPIO pin : PtPin */
+  GPIO_InitStruct.Pin = BUT_BLUE_Pin;
+  GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
+  GPIO_InitStruct.Pull = GPIO_NOPULL;
+  HAL_GPIO_Init(BUT_BLUE_GPIO_Port, &GPIO_InitStruct);
+
   /*Configure GPIO pin : PtPin */
   GPIO_InitStruct.Pin = LED_GREEN_Pin;
   GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
@@ -60,6 +66,10 @@ void MX_GPIO_Init(void)
   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
   HAL_GPIO_Init(LED_GREEN_GPIO_Port, &GPIO_InitStruct);
 
+  /* EXTI interrupt init*/
+  HAL_NVIC_SetPriority(EXTI0_IRQn, 5, 0);
+  HAL_NVIC_EnableIRQ(EXTI0_IRQn);
+
 }
 
 /* USER CODE BEGIN 2 */
diff --git a/Core/Src/stm32f4xx_it.c b/Core/Src/stm32f4xx_it.c
index 0ed7977..76611a5 100644
--- a/Core/Src/stm32f4xx_it.c
+++ b/Core/Src/stm32f4xx_it.c
@@ -182,6 +182,20 @@ void SysTick_Handler(void)
 /* please refer to the startup file (startup_stm32f4xx.s).                    */
 /******************************************************************************/
 
+/**
+  * @brief This function handles EXTI line0 interrupt.
+  */
+void EXTI0_IRQHandler(void)
+{
+  /* USER CODE BEGIN EXTI0_IRQn 0 */
+
+  /* USER CODE END EXTI0_IRQn 0 */
+  HAL_GPIO_EXTI_IRQHandler(BUT_BLUE_Pin);
+  /* USER CODE BEGIN EXTI0_IRQn 1 */
+
+  /* USER CODE END EXTI0_IRQn 1 */
+}
+
 /**
   * @brief This function handles USB On The Go FS global interrupt.
   */
diff --git a/raw407cxx.ioc b/raw407cxx.ioc
index 6c89df8..ac40714 100644
--- a/raw407cxx.ioc
+++ b/raw407cxx.ioc
@@ -7,6 +7,7 @@ FREERTOS.Tasks01=defaultTask,24,128,StartDefaultTask,Default,NULL,Dynamic,NULL,N
 FREERTOS.configENABLE_FPU=1
 FREERTOS.configUSE_NEWLIB_REENTRANT=1
 File.Version=6
+GPIO.groupedBy=Group By Peripherals
 KeepUserPlacement=false
 Mcu.CPN=STM32F407VGT6
 Mcu.Family=STM32F4
@@ -21,16 +22,17 @@ Mcu.Name=STM32F407V(E-G)Tx
 Mcu.Package=LQFP100
 Mcu.Pin0=PC14-OSC32_IN
 Mcu.Pin1=PC15-OSC32_OUT
-Mcu.Pin10=VP_USB_DEVICE_VS_USB_DEVICE_CDC_FS
+Mcu.Pin10=VP_FREERTOS_VS_CMSIS_V2
+Mcu.Pin11=VP_USB_DEVICE_VS_USB_DEVICE_CDC_FS
 Mcu.Pin2=PH0-OSC_IN
 Mcu.Pin3=PH1-OSC_OUT
-Mcu.Pin4=PA4
-Mcu.Pin5=PA5
-Mcu.Pin6=PD12
-Mcu.Pin7=PA11
-Mcu.Pin8=PA12
-Mcu.Pin9=VP_FREERTOS_VS_CMSIS_V2
-Mcu.PinsNb=11
+Mcu.Pin4=PA0-WKUP
+Mcu.Pin5=PA4
+Mcu.Pin6=PA5
+Mcu.Pin7=PD12
+Mcu.Pin8=PA11
+Mcu.Pin9=PA12
+Mcu.PinsNb=12
 Mcu.ThirdPartyNb=0
 Mcu.UserConstants=
 Mcu.UserName=STM32F407VGTx
@@ -38,6 +40,7 @@ MxCube.Version=6.8.1
 MxDb.Version=DB.6.0.81
 NVIC.BusFault_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:false
 NVIC.DebugMonitor_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:false
+NVIC.EXTI0_IRQn=true\:5\:0\:false\:false\:true\:true\:true\:true\:true
 NVIC.ForceEnableDMAVector=true
 NVIC.HardFault_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:false
 NVIC.MemoryManagement_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:false
@@ -51,6 +54,10 @@ NVIC.SavedSvcallIrqHandlerGenerated=true
 NVIC.SavedSystickIrqHandlerGenerated=true
 NVIC.SysTick_IRQn=true\:15\:0\:false\:false\:true\:true\:false\:true\:false
 NVIC.UsageFault_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:false
+PA0-WKUP.GPIOParameters=GPIO_Label
+PA0-WKUP.GPIO_Label=BUT_BLUE
+PA0-WKUP.Locked=true
+PA0-WKUP.Signal=GPXTI0
 PA11.Mode=Device_Only
 PA11.Signal=USB_OTG_FS_DM
 PA12.Mode=Device_Only
@@ -98,7 +105,7 @@ ProjectManager.StackSize=0x400
 ProjectManager.TargetToolchain=STM32CubeIDE
 ProjectManager.ToolChainLocation=
 ProjectManager.UnderRoot=true
-ProjectManager.functionlistsort=1-SystemClock_Config-RCC-false-HAL-false,2-MX_GPIO_Init-GPIO-false-HAL-true,3-MX_USB_DEVICE_Init-USB_DEVICE-false-HAL-false
+ProjectManager.functionlistsort=1-SystemClock_Config-RCC-false-HAL-false,2-MX_GPIO_Init-GPIO-false-HAL-true,3-MX_USB_DEVICE_Init-USB_DEVICE-false-HAL-false,4-MX_DAC_Init-DAC-false-HAL-true
 RCC.48MHZClocksFreq_Value=48000000
 RCC.AHBFreq_Value=168000000
 RCC.APB1CLKDivider=RCC_HCLK_DIV4
@@ -135,6 +142,8 @@ SH.COMP_DAC1_group.0=DAC_OUT1,DAC_OUT1
 SH.COMP_DAC1_group.ConfNb=1
 SH.COMP_DAC2_group.0=DAC_OUT2,DAC_OUT2
 SH.COMP_DAC2_group.ConfNb=1
+SH.GPXTI0.0=GPIO_EXTI0
+SH.GPXTI0.ConfNb=1
 USB_DEVICE.CLASS_NAME_FS=CDC
 USB_DEVICE.IPParameters=VirtualMode-CDC_FS,VirtualModeFS,CLASS_NAME_FS,PRODUCT_STRING_CDC_FS,MANUFACTURER_STRING-CDC_FS
 USB_DEVICE.MANUFACTURER_STRING-CDC_FS=Heck