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