#include "stm32l0xx_hal.h"

// LED pin definitions
#define RED_LED_PORT    GPIOA
#define RED_LED_PIN     GPIO_PIN_11   // D10

#define YELLOW_LED_PORT GPIOB
#define YELLOW_LED_PIN  GPIO_PIN_5   // D11

#define GREEN_LED_PORT  GPIOB
#define GREEN_LED_PIN   GPIO_PIN_4   // D12

void SystemClock_Config(void);

int main(void) {
  HAL_Init();
  SystemClock_Config();

  // Enable clocks for GPIOA and GPIOB
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  // Configure GPIO for all three LEDs
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

  // Red LED (D10 - PB6)
  GPIO_InitStruct.Pin = RED_LED_PIN;
  HAL_GPIO_Init(RED_LED_PORT, &GPIO_InitStruct);

  // Yellow LED (D11 - PA7)
  GPIO_InitStruct.Pin = YELLOW_LED_PIN;
  HAL_GPIO_Init(YELLOW_LED_PORT, &GPIO_InitStruct);

  // Green LED (D12 - PA6)
  GPIO_InitStruct.Pin = GREEN_LED_PIN;
  HAL_GPIO_Init(GREEN_LED_PORT, &GPIO_InitStruct);

  while (1) {
    // Red ON, Yellow & Green OFF
    HAL_GPIO_WritePin(RED_LED_PORT, RED_LED_PIN, GPIO_PIN_SET);
    HAL_GPIO_WritePin(YELLOW_LED_PORT, YELLOW_LED_PIN, GPIO_PIN_RESET);
    HAL_GPIO_WritePin(GREEN_LED_PORT, GREEN_LED_PIN, GPIO_PIN_RESET);
    HAL_Delay(3000); // 3 seconds

    // Yellow ON, Red & Green OFF
    HAL_GPIO_WritePin(RED_LED_PORT, RED_LED_PIN, GPIO_PIN_RESET);
    HAL_GPIO_WritePin(YELLOW_LED_PORT, YELLOW_LED_PIN, GPIO_PIN_SET);
    HAL_GPIO_WritePin(GREEN_LED_PORT, GREEN_LED_PIN, GPIO_PIN_RESET);
    HAL_Delay(1000); // 1 second

    // Green ON, Red & Yellow OFF
    HAL_GPIO_WritePin(RED_LED_PORT, RED_LED_PIN, GPIO_PIN_RESET);
    HAL_GPIO_WritePin(YELLOW_LED_PORT, YELLOW_LED_PIN, GPIO_PIN_RESET);
    HAL_GPIO_WritePin(GREEN_LED_PORT, GREEN_LED_PIN, GPIO_PIN_SET);
    HAL_Delay(2500); // 2.5 seconds
  }
}