diff --git a/.gdbinit b/.gdbinit
new file mode 100644
index 0000000..a4f8b46
--- /dev/null
+++ b/.gdbinit
@@ -0,0 +1,23 @@
+
+target remote localhost:3333
+set print pretty on
+set print elements 512
+set pagination off
+
+# Update GDB's Python paths with the `sys.path` values of the local Python installation,
+#  whether that is brew'ed Python, a virtualenv, or another system python.
+
+# Convert GDB to interpret in Python
+python
+import os,subprocess,sys
+# Execute a Python using the user's shell and pull out the sys.path (for site-packages)
+paths = subprocess.check_output('python -c "import os,sys;print(os.linesep.join(sys.path).strip())"',shell=True).decode("utf-8").split()
+# Extend GDB's Python's search path
+sys.path.extend(paths)
+print(sys.path)
+end
+
+#source upstream/PyCortexMDebug/cmdebug/svd_gdb.py
+#svd_load upstream/stm32square/svd/STM32G474.svd
+
+load
diff --git a/Makefile b/Makefile
index 239660b..793fe72 100644
--- a/Makefile
+++ b/Makefile
@@ -67,7 +67,7 @@ PYTHON3 ?= python3
 DOT		?= dot
 
 DEVICE_FAMILY	:= $(shell echo $(DEVICE) | grep -Eio 'STM32[a-z]{1,2}[0-9]'|cut -c 6-)
-DEVICE_DEFINES 	:= -D$(DEVICE) -DSTM32$(DEVICE_FAMILY) $(addprefix -D,$(shell cat stm32_buildinfo.defines))
+DEVICE_DEFINES 	:= -D$(DEVICE) -DHSE_VALUE=8000000U -DSTM32$(DEVICE_FAMILY) $(addprefix -D,$(shell cat stm32_buildinfo.defines))
 
 ARCH_FLAGS		?= -mthumb -mcpu=cortex-m3 -mfloat-abi=softfp
 SYSTEM_FLAGS	?= -nostdlib -ffreestanding -nostartfiles
diff --git a/src/main.c b/src/main.c
index 578fa5f..b9eaa4a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,56 +1,85 @@
 #include "main.h"
 
 __attribute__((section(".boot_counter"), aligned(1024)))
-uint32_t boot_counter[1024] = {[0 ... 1023] = 0xffffffff};
+uint32_t boot_counter[4096] = {[0 ... 4095] = 0xffffffff};
 void SystemClock_Config(void);
 
+/* Bluepill GPIO pins in physical board order (left side, then right side) */
+typedef struct {
+    GPIO_TypeDef *port;
+    uint16_t pin;
+} GPIO_Pin_t;
+
+static const GPIO_Pin_t light_pins[] = {
+    /* Left side (top to bottom) */
+    {GPIOB, GPIO_PIN_12}, /* yes */
+    {GPIOB, GPIO_PIN_13}, /* yes */
+    {GPIOB, GPIO_PIN_14}, /* yes */
+    {GPIOB, GPIO_PIN_15}, /* yes */
+    {GPIOA, GPIO_PIN_8},  /* yes */
+    {GPIOA, GPIO_PIN_9},  /* yes */
+    {GPIOA, GPIO_PIN_10}, /* yes */
+    {GPIOA, GPIO_PIN_11}, /* yes */
+    {GPIOB, GPIO_PIN_5},  /* yes */
+    {GPIOB, GPIO_PIN_6},  /* yes */
+    {GPIOB, GPIO_PIN_7},  /* yes */
+    {GPIOB, GPIO_PIN_8},  /* yes */
+    {GPIOB, GPIO_PIN_9},  /* yes */
+    {GPIOB, GPIO_PIN_10}, /* yes */
+    {GPIOB, GPIO_PIN_11}, /* yes */
+    {GPIOB, GPIO_PIN_1},  /* yes */
+    {GPIOA, GPIO_PIN_5},  /* yes */
+    {GPIOA, GPIO_PIN_4},  /* yes */
+};
+
+#define NUM_LIGHT_PINS (sizeof(light_pins) / sizeof(light_pins[0]))
+
+volatile int current_index = 0;
+
 static void MX_GPIO_Init(void)
 {
-  GPIO_InitTypeDef GPIO_InitStruct = {0};
+    GPIO_InitTypeDef GPIO_InitStruct = {0};
 
-  /* GPIO Ports Clock Enable */
-  __HAL_RCC_GPIOC_CLK_ENABLE();
-  __HAL_RCC_GPIOD_CLK_ENABLE();
-  __HAL_RCC_GPIOA_CLK_ENABLE();
+    /* GPIO Ports Clock Enable */
+    __HAL_RCC_GPIOC_CLK_ENABLE();
+    __HAL_RCC_GPIOD_CLK_ENABLE();
+    __HAL_RCC_GPIOA_CLK_ENABLE();
+    __HAL_RCC_GPIOB_CLK_ENABLE();
 
-  /*Configure GPIO pin Output Level */
-  HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);
+    /*Configure GPIO pin Output Level */
+    HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);
 
-  /*Configure GPIO pin : LED_Pin */
-  GPIO_InitStruct.Pin = LED_Pin;
-  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
-  GPIO_InitStruct.Pull = GPIO_PULLUP;
-  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
-  HAL_GPIO_Init(LED_GPIO_Port, &GPIO_InitStruct);
+    /*Configure GPIO pin : LED_Pin */
+    GPIO_InitStruct.Pin = LED_Pin;
+    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+    GPIO_InitStruct.Pull = GPIO_PULLUP;
+    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
+    HAL_GPIO_Init(LED_GPIO_Port, &GPIO_InitStruct);
 
+    /* LED output pins */
+    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+    GPIO_InitStruct.Pull = GPIO_NOPULL;
+    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
+
+    for (int i = 0; i < NUM_LIGHT_PINS; i++) {
+        GPIO_InitStruct.Pin = light_pins[i].pin;
+        HAL_GPIO_Init(light_pins[i].port, &GPIO_InitStruct);
+        HAL_GPIO_WritePin(light_pins[i].port, light_pins[i].pin, GPIO_PIN_RESET);
+    }
 }
 
 int get_and_increment_boot_count(void) {
     const size_t array_len = sizeof(boot_counter)/sizeof(boot_counter[0]);
-    int count = 0;
 
     for (size_t i=0; i<array_len; i++) {
-        uint32_t val = boot_counter[i];
-        if (val) {
-            for (int j=0; j<32; j++) {
-                uint32_t mask = 1<<j;
-                if (val & mask) {
-                    count = i*32 + j;
-
-                    HAL_FLASH_Unlock();
-                    uint32_t addr = (uint32_t)&boot_counter[i];
-                    uint32_t new_val = val & ~mask;
-                    HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, addr, new_val);
-                    HAL_FLASH_Lock();
-
-                    return count;
-                }
-            }
+        if (boot_counter[i]) {
+            HAL_FLASH_Unlock();
+            HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, (uint32_t)&boot_counter[i], 0);
+            HAL_FLASH_Lock();
+            return i;
         }
     }
 
-    count = array_len * 32;
-
     HAL_FLASH_Unlock();
 
     FLASH_EraseInitTypeDef erase_init;
@@ -60,102 +89,112 @@ int get_and_increment_boot_count(void) {
 
     uint32_t page_error;
     HAL_FLASHEx_Erase(&erase_init, &page_error);
-
     HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, (uint32_t)&boot_counter[0], 0xfffffffe);
-
     HAL_FLASH_Lock();
 
-    return count;
+    return array_len;
 }
 
 uint32_t xorshift32(uint32_t x)
 {
-	/* Algorithm "xor" from p. 4 of Marsaglia, "Xorshift RNGs" */
-	x ^= x << 13;
-	x ^= x >> 17;
-	x ^= x << 5;
-	return x;
+    /* Algorithm "xor" from p. 4 of Marsaglia, "Xorshift RNGs" */
+    x ^= x << 13;
+    x ^= x >> 17;
+    x ^= x << 5;
+    return x;
+}
+
+void increment_light(void) {
+
+    /* The boot counter is in FLASH, increment it before other initialization */
+    int boot_count = get_and_increment_boot_count();
+
+    uint32_t seed = 0xc8f1de1f;
+    for (int i=0; i<boot_count; i++) {
+        seed = xorshift32(seed);
+    }
+    HAL_GPIO_WritePin(light_pins[current_index].port, light_pins[current_index].pin, GPIO_PIN_RESET);
+
+    current_index = seed % NUM_LIGHT_PINS;
+    /* Turn on current pin */
+    HAL_GPIO_WritePin(light_pins[current_index].port, light_pins[current_index].pin, GPIO_PIN_SET);
 }
 
 int main(void)
 {
-  HAL_Init();
-  SystemClock_Config();
+    HAL_Init();
+    SystemClock_Config();
 
-  /* The boot counter is in FLASH, increment it before other initialization */
-  int boot_count = get_and_increment_boot_count();
+    MX_GPIO_Init();
 
-  MX_GPIO_Init();
+    for (int i=0; i<10; i++) {
+        HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_SET);
+        HAL_Delay(50);
+        HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);
+        HAL_Delay(50);
+    }
 
-  HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);
-  HAL_Delay(500);
-  HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_SET);
-  HAL_Delay(500);
-  HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);
-  HAL_Delay(500);
-  HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_SET);
-  HAL_Delay(500);
-  HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);
-  HAL_Delay(500);
-  HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_SET);
-  HAL_Delay(500);
-  HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);
 
-  uint32_t seed = 0xc8f1de1f;
-  for (int i=0; i<boot_count; i++) {
-      seed = xorshift32(seed);
-  }
-
-  while (1) {
-  }
+    while (1) {
+        increment_light();
+        for (int day=0; day<14; day++) {
+            for (int hour=0; hour<24; hour++) {
+                for (int minute=0; minute<60; minute++) {
+                    for (int second=0; second<60; second++) {
+                        HAL_Delay(1000);
+                    }
+                }
+            }
+        }
+    }
 }
 void SystemClock_Config(void)
 {
-  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
-  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
-  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
+    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
+    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
+    RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
 
-  /** Initializes the RCC Oscillators according to the specified parameters
-  * in the RCC_OscInitTypeDef structure.
-  */
-  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
-  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
-  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
-  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
-  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
-  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
-  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
-  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
-  {
-    Error_Handler();
-  }
-  /** Initializes the CPU, AHB and APB buses clocks
-  */
-  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
-                              |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.APB2CLKDivider = RCC_HCLK_DIV1;
+    /** Initializes the RCC Oscillators according to the specified parameters
+     * in the RCC_OscInitTypeDef structure.
+     */
+    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
+    RCC_OscInitStruct.HSEState = RCC_HSE_ON;
+    RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
+    RCC_OscInitStruct.HSIState = RCC_HSI_ON;
+    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
+    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
+    RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
+    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
+    {
+        Error_Handler();
+    }
+    /** Initializes the CPU, AHB and APB buses clocks
+    */
+    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
+        |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.APB2CLKDivider = RCC_HCLK_DIV1;
 
-  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
-  {
-    Error_Handler();
-  }
-  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB;
-  PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_PLL_DIV1_5;
-  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
-  {
-    Error_Handler();
-  }
+    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
+    {
+        Error_Handler();
+    }
+    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB;
+    PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_PLL_DIV1_5;
+    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
+    {
+        Error_Handler();
+    }
 }
 
 void Error_Handler(void)
 {
-  __disable_irq();
-  while (1)
-  {
-  }
+    __disable_irq();
+    while (1)
+    {
+    }
 }
 
 #ifdef  USE_FULL_ASSERT