diff --git a/Core/Inc/stm32f4xx_hal_conf.h b/Core/Inc/stm32f4xx_hal_conf.h
index bcd6891..2763fb1 100644
--- a/Core/Inc/stm32f4xx_hal_conf.h
+++ b/Core/Inc/stm32f4xx_hal_conf.h
@@ -100,7 +100,7 @@
 #endif /* HSE_VALUE */
 
 #if !defined  (HSE_STARTUP_TIMEOUT)
-  #define HSE_STARTUP_TIMEOUT    1000U   /*!< Time out for HSE start up, in ms */
+  #define HSE_STARTUP_TIMEOUT    100U   /*!< Time out for HSE start up, in ms */
 #endif /* HSE_STARTUP_TIMEOUT */
 
 /**
diff --git a/Core/Src/main.c b/Core/Src/main.c
index 43b6066..5f49e19 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -21,6 +21,7 @@
 
 /* Private includes ----------------------------------------------------------*/
 /* USER CODE BEGIN Includes */
+#include <stdio.h>
 
 /* USER CODE END Includes */
 
@@ -58,7 +59,7 @@ static void MX_USART2_UART_Init(void);
 
 /* Private user code ---------------------------------------------------------*/
 /* USER CODE BEGIN 0 */
-static const char heartbeat_msg[] = "PB6 heartbeat\r\n";
+static char heartbeat_buf[64];
 
 /* USER CODE END 0 */
 
@@ -101,9 +102,16 @@ int main(void)
   /* USER CODE BEGIN WHILE */
 	while (1) {
 		HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_6);
-		/* Heartbeat: emit status over UART1 and blink the PB6 LED */
-		HAL_UART_Transmit(&huart1, (uint8_t *)heartbeat_msg,
-						  sizeof(heartbeat_msg) - 1, HAL_MAX_DELAY);
+		/* Heartbeat: emit tick timestamp over UART1 and blink the PB6 LED */
+		int msg_len = snprintf(heartbeat_buf, sizeof(heartbeat_buf),
+							   "PB6 heartbeat %lu\r\n", (unsigned long)HAL_GetTick());
+		if (msg_len > 0) {
+			if (msg_len >= (int)sizeof(heartbeat_buf)) {
+				msg_len = (int)sizeof(heartbeat_buf) - 1;
+			}
+			HAL_UART_Transmit(&huart1, (uint8_t *)heartbeat_buf, (uint16_t)msg_len,
+							  HAL_MAX_DELAY);
+		}
 		HAL_Delay(1000);
     /* USER CODE END WHILE */
 
@@ -124,7 +132,7 @@ void SystemClock_Config(void)
   /** Configure the main internal regulator output voltage
   */
   __HAL_RCC_PWR_CLK_ENABLE();
-  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);
+  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
 
   /** Initializes the RCC Oscillators according to the specified parameters
   * in the RCC_OscInitTypeDef structure.
@@ -134,7 +142,7 @@ void SystemClock_Config(void)
   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
   RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
   RCC_OscInitStruct.PLL.PLLM = 8;
-  RCC_OscInitStruct.PLL.PLLN = 128;
+  RCC_OscInitStruct.PLL.PLLN = 192;
   RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
   RCC_OscInitStruct.PLL.PLLQ = 4;
   if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
@@ -148,13 +156,14 @@ void SystemClock_Config(void)
                               |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
   RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
   RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
-  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
+  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
   RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
 
   if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
   {
     Error_Handler();
   }
+  HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_PLLCLK, RCC_MCODIV_2);
 }
 
 /**
@@ -244,6 +253,14 @@ static void MX_GPIO_Init(void)
   /*Configure GPIO pin Output Level */
   HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_SET);
 
+  /*Configure GPIO pin : PA8 */
+  GPIO_InitStruct.Pin = GPIO_PIN_8;
+  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
+  GPIO_InitStruct.Pull = GPIO_NOPULL;
+  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
+  GPIO_InitStruct.Alternate = GPIO_AF0_MCO;
+  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
+
   /*Configure GPIO pin : PB6 */
   GPIO_InitStruct.Pin = GPIO_PIN_6;
   GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..6801eba
--- /dev/null
+++ b/README.md
@@ -0,0 +1 @@
+Generated by CubeMX, just for testing
diff --git a/flash_openocd.sh b/flash_openocd.sh
new file mode 100755
index 0000000..c569a53
--- /dev/null
+++ b/flash_openocd.sh
@@ -0,0 +1,8 @@
+#!/usr/bin/env sh
+
+openocd \
+  -f interface/cmsis-dap.cfg \
+  -f target/stm32f4x.cfg \
+  -c "adapter speed 4000" \
+  -c "transport select swd" \
+  -c "program build/stmf411re_test.elf verify reset exit"
\ No newline at end of file
diff --git a/flash_probe_rs.sh b/flash_probe_rs.sh
new file mode 100755
index 0000000..1b1871e
--- /dev/null
+++ b/flash_probe_rs.sh
@@ -0,0 +1,3 @@
+#!/usr/bin/env sh
+
+probe-rs download --chip STM32F411RE build/stmf411re_test.elf --verify
\ No newline at end of file
diff --git a/flash.sh b/flash_stm32_programmer.sh
similarity index 100%
rename from flash.sh
rename to flash_stm32_programmer.sh
diff --git a/stmf411re_test.ioc b/stmf411re_test.ioc
index 2173456..d265e65 100644
--- a/stmf411re_test.ioc
+++ b/stmf411re_test.ioc
@@ -17,18 +17,19 @@ Mcu.Name=STM32F411R(C-E)Tx
 Mcu.Package=LQFP64
 Mcu.Pin0=PC14-OSC32_IN
 Mcu.Pin1=PC15-OSC32_OUT
-Mcu.Pin10=PB3
-Mcu.Pin11=PB6
-Mcu.Pin12=VP_SYS_VS_Systick
+Mcu.Pin10=PA14
+Mcu.Pin11=PB3
+Mcu.Pin12=PB6
+Mcu.Pin13=VP_SYS_VS_Systick
 Mcu.Pin2=PH0 - OSC_IN
 Mcu.Pin3=PH1 - OSC_OUT
 Mcu.Pin4=PA2
 Mcu.Pin5=PA3
-Mcu.Pin6=PA9
-Mcu.Pin7=PA10
-Mcu.Pin8=PA13
-Mcu.Pin9=PA14
-Mcu.PinsNb=13
+Mcu.Pin6=PA8
+Mcu.Pin7=PA9
+Mcu.Pin8=PA10
+Mcu.Pin9=PA13
+Mcu.PinsNb=14
 Mcu.ThirdPartyNb=0
 Mcu.UserConstants=
 Mcu.UserName=STM32F411RETx
@@ -67,6 +68,8 @@ PA3.GPIO_Label=USART_RX
 PA3.Locked=true
 PA3.Mode=Asynchronous
 PA3.Signal=USART2_RX
+PA8.Mode=Clock-out-1
+PA8.Signal=RCC_MCO_1
 PA9.Mode=Asynchronous
 PA9.Signal=USART1_TX
 PB3.GPIOParameters=GPIO_Label
@@ -120,41 +123,42 @@ ProjectManager.UAScriptAfterPath=
 ProjectManager.UAScriptBeforePath=
 ProjectManager.UnderRoot=false
 ProjectManager.functionlistsort=1-SystemClock_Config-RCC-false-HAL-false,2-MX_GPIO_Init-GPIO-false-HAL-true,3-MX_USART1_UART_Init-USART1-false-HAL-true,4-MX_USART2_UART_Init-USART2-false-HAL-true
-RCC.48MHZClocksFreq_Value=32000000
-RCC.AHBFreq_Value=32000000
-RCC.APB1CLKDivider=RCC_HCLK_DIV2
-RCC.APB1Freq_Value=16000000
-RCC.APB1TimFreq_Value=32000000
-RCC.APB2Freq_Value=32000000
-RCC.APB2TimFreq_Value=32000000
-RCC.CortexFreq_Value=32000000
-RCC.EthernetFreq_Value=32000000
-RCC.FCLKCortexFreq_Value=32000000
+RCC.48MHZClocksFreq_Value=48000000
+RCC.AHBFreq_Value=48000000
+RCC.APB1Freq_Value=48000000
+RCC.APB1TimFreq_Value=48000000
+RCC.APB2Freq_Value=48000000
+RCC.APB2TimFreq_Value=48000000
+RCC.CortexFreq_Value=48000000
+RCC.EthernetFreq_Value=48000000
+RCC.FCLKCortexFreq_Value=48000000
 RCC.FLatency-AdvancedSettings=FLASH_LATENCY_1
 RCC.FamilyName=M
-RCC.HCLKFreq_Value=32000000
-RCC.HSE_Timout=1000
+RCC.HCLKFreq_Value=48000000
 RCC.HSE_VALUE=8000000
 RCC.HSI_VALUE=16000000
 RCC.I2SClocksFreq_Value=48000000
-RCC.IPParameters=48MHZClocksFreq_Value,AHBFreq_Value,APB1CLKDivider,APB1Freq_Value,APB1TimFreq_Value,APB2Freq_Value,APB2TimFreq_Value,CortexFreq_Value,EthernetFreq_Value,FCLKCortexFreq_Value,FLatency-AdvancedSettings,FamilyName,HCLKFreq_Value,HSE_Timout,HSE_VALUE,HSI_VALUE,I2SClocksFreq_Value,LSI_VALUE,MCO2PinFreq_Value,PLLCLKFreq_Value,PLLM,PLLN,PLLP,PLLQCLKFreq_Value,PLLSourceVirtual,PWR_Regulator_Voltage_Scale,RTCFreq_Value,RTCHSEDivFreq_Value,SYSCLKFreq_VALUE,SYSCLKSource,VCOI2SOutputFreq_Value,VCOInputFreq_Value,VCOInputMFreq_Value,VCOOutputFreq_Value,VcooutputI2S
+RCC.IPParameters=48MHZClocksFreq_Value,AHBFreq_Value,APB1Freq_Value,APB1TimFreq_Value,APB2Freq_Value,APB2TimFreq_Value,CortexFreq_Value,EthernetFreq_Value,FCLKCortexFreq_Value,FLatency-AdvancedSettings,FamilyName,HCLKFreq_Value,HSE_VALUE,HSI_VALUE,I2SClocksFreq_Value,LSE_VALUE,LSI_VALUE,MCO1PinFreq_Value,MCO2PinFreq_Value,PLLCLKFreq_Value,PLLM,PLLP,PLLQCLKFreq_Value,PLLSourceVirtual,PWR_Regulator_Voltage_Scale,RCC_MCO1Source,RCC_MCODiv1,RTCFreq_Value,RTCHSEDivFreq_Value,SYSCLKFreq_VALUE,SYSCLKSource,VCOI2SOutputFreq_Value,VCOInputFreq_Value,VCOInputMFreq_Value,VCOOutputFreq_Value,VcooutputI2S
+RCC.LSE_VALUE=32768
 RCC.LSI_VALUE=32000
-RCC.MCO2PinFreq_Value=32000000
-RCC.PLLCLKFreq_Value=32000000
+RCC.MCO1PinFreq_Value=24000000
+RCC.MCO2PinFreq_Value=48000000
+RCC.PLLCLKFreq_Value=48000000
 RCC.PLLM=8
-RCC.PLLN=128
 RCC.PLLP=RCC_PLLP_DIV4
-RCC.PLLQCLKFreq_Value=32000000
+RCC.PLLQCLKFreq_Value=48000000
 RCC.PLLSourceVirtual=RCC_PLLSOURCE_HSE
-RCC.PWR_Regulator_Voltage_Scale=PWR_REGULATOR_VOLTAGE_SCALE3
+RCC.PWR_Regulator_Voltage_Scale=PWR_REGULATOR_VOLTAGE_SCALE2
+RCC.RCC_MCO1Source=RCC_MCO1SOURCE_PLLCLK
+RCC.RCC_MCODiv1=RCC_MCODIV_2
 RCC.RTCFreq_Value=32000
 RCC.RTCHSEDivFreq_Value=4000000
-RCC.SYSCLKFreq_VALUE=32000000
+RCC.SYSCLKFreq_VALUE=48000000
 RCC.SYSCLKSource=RCC_SYSCLKSOURCE_PLLCLK
 RCC.VCOI2SOutputFreq_Value=96000000
 RCC.VCOInputFreq_Value=1000000
 RCC.VCOInputMFreq_Value=500000
-RCC.VCOOutputFreq_Value=128000000
+RCC.VCOOutputFreq_Value=192000000
 RCC.VcooutputI2S=48000000
 USART1.IPParameters=VirtualMode
 USART1.VirtualMode=VM_ASYNC