I2C EEPROM示例
源码路径：example/rt_device/i2c/eeprom
支持的平台
例程可以运行在以下开发板.
em-lb525
em-lb587
概述
在RT-Thread操作系统下,通过对EEPROM芯片AT24CO8SC模块的读写操作，演示I2C的使用方法
例程的使用
硬件连接
AT24CO8SC的VCC,GND分别连接5v和GND供电
AT24CO8SC的SDA,SCK分别按照下表，根据开发板型号进行连接
开发板 |
SDA管脚 |
SDA管脚名称 |
SCL管脚 |
SCL管脚名称 |
|---|---|---|---|---|
em-lb525 |
3 |
PA42 |
5 |
PA41 |
em-lb587 |
3 |
PB29 |
PB28 |
更详细的引脚定义请参考
[em-lb525]()
[em-lb587]()AT24C08SC
编译和烧录
此例程中用到了I2C2，在采用RT-Thread操作系统时，I2C2外设会虚拟成了一个rt_device来进行读写操作，此时需要确认工程所在路径下
rtconfig.h文件中是否包含了下面3个宏：
#define RT_USING_I2C 1
#define BSP_USING_I2C 1
#define BSP_USING_I2C2 1
只有包含了上面三个宏，在rt_hw_i2c_init2函数中才会通过rt_i2c_bus_device_register函数注册"i2c2"这个rt_device，后面该设备才能rt_device_find和rt_device_open成功。
如果缺失上面三个宏，就需要通过menuconfig如下命令进行打开
menuconfig --board=em-lb525
如下图，选择I2C2，保存并退出menuconfig，查看rtconfig.h宏是否生成
SF525工程代码编译
切换到例程project目录，运行scons命令执行编译：
scons --board=em-lb525 -j8
运行build_em-lb525_hcpu\uart_download.bat，按提示选择端口即可进行下载：
build_em-lb525_hcpu\uart_download.bat
Uart Download
please input the serial port num:5
SF587工程代码编译
切换到例程project目录，运行scons命令执行编译：
scons --board=em-lb587 -j8
切换到例程project/build_xx目录，运行download.bat，程序通过JLink自动下载：
build_em-lb587_hcpu\download.bat
例程输出结果展示:
log输出:
SFBL
Serial:c2,Chip:4,Package:3,Rev:3 Reason:00000000
\ | /
- SiFli Corporation
/ | \ build on Dec 6 2024, 2.1.7 build 779fe6ee
2020 - 2022 Copyright by SiFli team
mount /dev sucess
[32m][2009] I/drv.rtc: PSCLR=0x80000100 DivAI=128 DivAF=0 B=256
[0m][32m][2036] I/drv.rtc: RTC use LXT RTC_CR=00000001
[0m][32m][2058] I/drv.rtc: Init RTC, wake = 0
[0m][32m][2220] I/drv.audprc: init 00 ADC_PATH_CFG0 0x606
[0m][32m][2242] I/drv.audprc: HAL_AUDPRC_Init res 0
[0m][32m][2264] I/drv.audcodec: HAL_AUDCODEC_Init res 0
[0m][32m][2286] I/TOUCH: Regist touch screen driver, probe=1203b8b1
[0m]call par CFG1(3313)
fc 9, xtal 2000, pll 2123
call par CFG1(3313)
fc 7, xtal 2000, pll 1698
main!!
[2448] D/eeprom_i2c: Start i2c eeprom rtt demo!
i2c_bus:0x20007f50
Find i2c bus device I2C2
[2492] D/eeprom_i2c: i2c write reg:0x1,data:0x11,ret:1
[2681] D/eeprom_i2c: i2c write reg:0x2,data:0x22,ret:1
[2869] D/eeprom_i2c: i2c write reg:0x3,data:0x33,ret:1
[3058] D/eeprom_i2c: i2c write reg:0x4,data:0x44,ret:1
[3248] D/eeprom_i2c: i2c read reg:0x1,pdata:0x11,ret:1
[3273] D/eeprom_i2c: i2c read reg:0x2,pdata:0x22,ret:1
[3298] D/eeprom_i2c: i2c read reg:0x3,pdata:0x33,ret:1
[3323] D/eeprom_i2c: i2c read reg:0x4,pdata:0x44,ret:1
[3345] D/eeprom_i2c: i2c end!
msh />
AT24C08SC芯片手册上要求的i2c读写波形
i2c写的波形
i2c读的波形
逻辑分析仪抓取部分波形
i2c写的波形
i2c读的波形
I2C参数修改
见EEPROM_init函数内注释
unsigned char EEPROM_init(void)
{
uint8_t slaveAddr = EEPROM_I2C_ADDRESS; // 7bit address of device
HAL_StatusTypeDef ret;
//1. pin mux
#ifdef SF32LB52X
HAL_PIN_Set(PAD_PA41, I2C2_SCL, PIN_PULLUP, 1); // i2c io select
HAL_PIN_Set(PAD_PA42, I2C2_SDA, PIN_PULLUP, 1);
#elif defined(SF32LB58X)
HAL_PIN_Set(PAD_PB28, I2C6_SCL, PIN_PULLUP, 1); // i2c io select
HAL_PIN_Set(PAD_PB29, I2C6_SDA, PIN_PULLUP, 1);
#endif
// 2. i2c init
// find i2c2
#ifdef SF32LB52X
i2c_bus = rt_i2c_bus_device_find("i2c2");
#elif defined(SF32LB58X)
i2c_bus = rt_i2c_bus_device_find("i2c6");
#endif
rt_kprintf("i2c_bus:0x%x\n", i2c_bus);
if (i2c_bus)
{
#ifdef SF32LB52X
rt_kprintf("Find i2c bus device I2C2\n");
#elif defined(SF32LB58X)
rt_kprintf("Find i2c bus device I2C6\n");
#endif
// open rt_device i2c2
rt_device_open((rt_device_t)i2c_bus, RT_DEVICE_FLAG_RDWR);
//rt_i2c_open(i2c_bus, RT_DEVICE_FLAG_RDWR);
struct rt_i2c_configuration configuration =
{
.mode = 0,
.addr = 0,
.timeout = 500, //Waiting for timeout period (ms)
.max_hz = 400000, //I2C rate (hz)
};
// config I2C parameter
rt_i2c_configure(i2c_bus, &configuration);
}
else
{
#ifdef SF32LB52X
LOG_E("Can not found i2c bus I2C2, init fail\n");
#elif defined(SF32LB58X)
LOG_E("Can not found i2c bus I2C6, init fail\n");
#endif
return -1;
}
return 0;
}
在打开rt_device设备时，如果采用rt_i2c_open函数，功能上没有发现问题，但是
list_device时i2c2不会显示open状态,
rt_i2c_open(i2c_bus, RT_DEVICE_FLAG_RDWR);
msh />
TX:list_device
list_device
device type ref count
-------- -------------------- ----------
audcodec Sound Device 0
audprc Sound Device 0
rtc RTC 0
pwm3 Miscellaneous Device 0
touch Graphic Device 0
lcdlight Character Device 0
lcd Graphic Device 0
i2c4 I2C Bus 0
i2c2 I2C Bus 0
i2c1 I2C Bus 0
lptim1 Timer Device 0
btim1 Timer Device 0
uart1 Character Device 2
pin Miscellaneous Device 0
msh />
采用rt_device_open时
rt_device_open((rt_device_t)i2c_bus, RT_DEVICE_FLAG_RDWR);
msh />
TX:list_device
list_device
device type ref count
-------- -------------------- ----------
audcodec Sound Device 0
audprc Sound Device 0
rtc RTC 0
pwm3 Miscellaneous Device 0
touch Graphic Device 0
lcdlight Character Device 0
lcd Graphic Device 0
i2c4 I2C Bus 0
i2c2 I2C Bus 1
i2c1 I2C Bus 0
lptim1 Timer Device 0
btim1 Timer Device 0
uart1 Character Device 2
pin Miscellaneous Device 0
这里只是演示了I2C的一种用法，在I2C外设要求的波形跟示例不一致时，可以参考rt_i2c_transfer函数的用法。
注意:
除SF32LB55x芯片外，所有PA口都支持HCPU I2C的SDA、SCL功能，所有PB口都支持LCPU I2C的SDA、SCL功能
HCPU的PA口不能配置为LCPU的I2C实例使用，LCPU的PB口也不能配置为HCPU的I2C使用， 比如I2C5是LCPU的I2C实例，他的SCL和SDA管脚不能映射到PA口
HAL_PIN_Set 最后一个参数为hcpu/lcpu选择, 1:选择hcpu,0:选择lcpu
异常诊断
I2C无波形输出
pin status 39命令查看对应PA39，PA40的IO状态FUNC对不对，VAL电平应该是1
msh />
TX:pin status 39
pin status 39
[32m][215653658] I/TEST.GPIO: PIN 39, FUNC=4, VAL=1, DIG_IO_PU, GPIO_MODE_INPUT, irqhdr=/, arg=/
[0m]
msh />
msh />
TX:pin status 40
pin status 40
[32m][215753678] I/TEST.GPIO: PIN 40, FUNC=4, VAL=1, DIG_IO_PU, GPIO_MODE_INPUT, irqhdr=/, arg=/
[0m]
msh />
msh />
‘list_device’命令查看’i2c2’设备是不是存在并且打开了
检查IO配置和连接是否正确
连写失败，I2C波形正常，无应答信号
AT24C08SC写输入时需要至多5ms Write Cycle Time等待数据烧录
void EEPROM_test(void)
{
unsigned char i = 0;
for ( i = 0; i < 4; i++)
{
EEPROM_write_data(TEST_ADDR[i], TEST_DATA[i]);
delayms(5); //5ms delay for AT240C8SC write time cycle
}
for ( i = 0; i < 4; i++)
{
EEPROM_read_data(TEST_ADDR[i], &RECEIVED);
}
}
参考文档
更新记录
版本 |
日期 |
发布说明 |
|---|---|---|
0.0.1 |
10/2024 |
初始版本 |