BearPi Std 板从入门到放弃 - 后天篇（2）(I2C1读写EEPROM)

简介

基于 BearPi Std 板从入门到放弃 - 后天篇（1）(I2C1 读取 光照强度)， 使用同一个I2C接口访问EEPROM, 同时读取光照亮度
主芯片: STM32L431RCT6
LED : PC13 \ 推挽输出即可 \ 高电平点亮
串口: Usart1
I2C : I2C1
光照强度传感器：BH1750
EEPROM芯片 : AT24C02

芯片说明

1. BearPi 自带的扩展版 E53_SC1_智慧路灯的原理图
   

2. AT2402C 基本描述, 2Kbit, 32Page, 每个Page 1 Byte， 所以地址是0~255

3. AT2402C 的 设备地址规则
   

4. 结论
   a. 结合 原理图,
   A0 = 1; A1 = 0; A2 =0;
   写的地址 = 10100010 = 0xA2
   读的地址 = 10100011 = 0xA3

b. 2Kbit, 32Page, 每个Page 1 Byte， 所以地址是0~255

步骤

1. 基于前面文章, 创建工程
2. 添加读写代码

#define AT24C02_WRITE_ADDRESS 0xA2
#define AT24C02_READ_ADDRESS 0xA3

/* 写单个字节 */
uint8_t AT24C02_Write_Byte(uint16_t addr, uint8_t *dat)
{
	return HAL_I2C_Mem_Write(&hi2c1, AT24C02_WRITE_ADDRESS, addr, I2C_MEMADD_SIZE_8BIT, dat, 1, 0xffff);
}
/* 读取单个字节 */
uint8_t AT24C02_Read_Byte(uint16_t addr, uint8_t *buf)
{
	return HAL_I2C_Mem_Read(&hi2c1, AT24C02_READ_ADDRESS, addr, I2C_MEMADD_SIZE_8BIT, buf, 1, 0xffff);
}

/* 读多个字节 */
uint8_t AT24C02_Read_Bytes(uint16_t addr, uint8_t *buf, uint16_t bufSize)
{
	return HAL_I2C_Mem_Read(&hi2c1, AT24C02_READ_ADDRESS, addr, I2C_MEMADD_SIZE_8BIT, buf, bufSize, 0xffff);
}

int main()
{
	...
	uint8_t res = 0;
	uint8_t datTemp = 0;
	/* 写完整个EEPROM */
	for (int i = 0; i < 256; ++i)
	{
		datTemp  = i;
		res = AT24C02_Write_Byte(i, &datTemp);
		if (res)
		{
			printf("Faile To Write Address %d!\r\n", i);
		}
		HAL_Delay(10); // 写延时, 不然会失败
	}
	
	/* 读完整个EEPROM */
	for (int i = 0; i < 256; ++i)
	{
		res = AT24C02_Read_Byte(i, &datTemp);
		if (res)
		{
			printf("Faile To ReadAddress %d!\r\n", i);
		}
		else
		{
			printf("Address: %d, Value: %d\r\n", i, datTemp);
		}
	}

	while(1)
	{
		...
	}
}

BearPi I2C1 完整项目工程, 包含两份芯片datasheet