#include "main.h"

I2C_HandleTypeDef hi2c1;

void SystemClock_Config(void);
static void MX_I2C1_Init(void);

static void clear_addr_tab(unsigned char *addr_tab)
{
	unsigned int i = 0;
	for (i = 0; i < 128; i++) {
		addr_tab[i] = 0;
	}
}

unsigned char i2c_scan(unsigned char *addr_tab)
{
	HAL_StatusTypeDef result;
	uint8_t addr;
	unsigned char found = 0;
	for (addr = 1; addr < 128; addr++) {
		result = HAL_I2C_IsDeviceReady(&hi2c1, (uint16_t) (addr << 1), 2, 100);
		if (result != HAL_OK) {
			// HAL_ERROR or HAL_BUSY or HAL_TIMEOUT
			// 无ACK
			addr_tab[addr] = 0;
		} else {
			// 有ACK：有设备存在
			addr_tab[found] = addr;
			found += 1;
		}
	}
	return found;
}

int main(void)
{
	// 此例程中的"volatile"仅用于观察数据（volatile会阻止编译器对目标的优化），移植的时候请去掉"volatile"修饰词
	volatile unsigned char found;
	unsigned char addr_tab[128]; // 存找到的设备地址，地址会排在前面，不等于0的数组就是设备地址
	volatile char* volatile addr_ptr = (char *)addr_tab; //没啥用，就是防止unsed 的 addr_tab被优化掉。

	HAL_Init();
	SystemClock_Config();
	MX_I2C1_Init();

	while (1) {
		// 初始化
		found = 0;
		clear_addr_tab((unsigned char *)addr_tab);

		found = i2c_scan((unsigned char *)addr_tab);
		/* 扫描完毕,用debug查看found是否>=1,>=1的情况下,地址存于addr_tab,数组不是0的就是找到的设备地址 */

		// 等待1ms
		HAL_Delay(1);
	}
}

/**
 * @brief 时钟配置
 */
void SystemClock_Config(void)
{
	RCC_OscInitTypeDef RCC_OscInitStruct = {0};
	RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

	/** Initializes the RCC Oscillators according to the specified parameters
	 * in the RCC_OscInitTypeDef structure.
	 */
	RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
	RCC_OscInitStruct.HSIState = RCC_HSI_ON;
	RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
	RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
	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_HSI;
	RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
	RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
	RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

	if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK) {
		Error_Handler();
	}
}

/**
 * @brief I2C初始化
 */
static void MX_I2C1_Init(void)
{
	/* 主设备设置 */
	hi2c1.Instance = I2C1; /* i2c通道 */
	hi2c1.Init.ClockSpeed = 100000;
	hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2; /* i2c 占空比=50% 1:1, I2C_DUTYCYCLE_16_9 用于快速i2c模式 */

	/* 从设备设置(不用管) */
	hi2c1.Init.OwnAddress1 = 0;
	hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
	hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
	hi2c1.Init.OwnAddress2 = 0;
	hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
	hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;

	/* 是否初始化成功 */
	if (HAL_I2C_Init(&hi2c1) != HAL_OK) {
		Error_Handler();
	}
}

/* 出错啦 */
void Error_Handler(void)
{
	__disable_irq();
	while (1) {

	}
}