我之前发了测评 GPIO和UART的,这次是测评IIC(软件)的。
软件配置
在FSP中关闭IIC使能
在stduio 中打开软件IIC
**记住这里一定是 0x50c 0x50b 创建工程配置的不是这样,我找了半天才找到是因为这个,我一直没有把IIC,调好,我也不知道为什么,希望有大佬解释一下。
代码编写
创建 aht10.c 文件 ,复制rt例子中的i2c_aht10_sample.c 代码,我开始准备自己写的,但是看到这里有现成的代码就拿来直接使用了。
#include
#include
#define AHT10_I2C_BUS_NAME "i2c1" /* 传感器连接的I2C总线设备名称 */
#define AHT10_ADDR 0x38 /* 从机地址 */
#define AHT10_CALIBRAtiON_CMD 0xE1 /* 校准命令 */
#define AHT10_NORMAL_CMD 0xA8 /* 一般命令 */
#define AHT10_GET_DATA 0xAC /* 获取数据命令 */
static struct rt_i2c_bus_device *i2c_bus = RT_NULL; /* I2C总线设备句柄 */
static rt_bool_t initialized = RT_FALSE; /* 传感器初始化状态 */
/* 写传感器寄存器 */
static rt_err_t write_reg(struct rt_i2c_bus_device *bus, rt_uint8_t reg, rt_uint8_t *data)
{
rt_uint8_t buf[3];
struct rt_i2c_msg msgs;
buf[0] = reg; //cmd
buf[1] = data[0];
buf[2] = data[1];
msgs.addr = AHT10_ADDR;
msgs.flags = RT_I2C_WR;
msgs.buf = buf;
msgs.len = 3;
/* 调用I2C设备接口传输数据 */
if (rt_i2c_transfer(bus, &msgs, 1) == 1)
{
return RT_EOK;
}
else
{
return -RT_ERROR;
}
}
/* 读传感器寄存器数据 */
static rt_err_t read_regs(struct rt_i2c_bus_device *bus, rt_uint8_t len, rt_uint8_t *buf)
{
struct rt_i2c_msg msgs;
msgs.addr = AHT10_ADDR;
msgs.flags = RT_I2C_RD;
msgs.buf = buf;
msgs.len = len;
/* 调用I2C设备接口传输数据 */
if (rt_i2c_transfer(bus, &msgs, 1) == 1)
{
return RT_EOK;
}
else
{
return -RT_ERROR;
}
}
static void read_temp_humi(float *cur_temp, float *cur_humi)
{
rt_uint8_t temp[6];
write_reg(i2c_bus, AHT10_GET_DATA, 0); /* 发送命令 */
read_regs(i2c_bus, 6, temp); /* 获取传感器数据 */
/* 湿度数据转换 */
*cur_humi = (temp[1] << 12 | temp[2] << 4 | (temp[3] & 0xf0) >> 4) * 100.0 / (1 << 20);
/* 温度数据转换 */
*cur_temp = ((temp[3] & 0xf) << 16 | temp[4] << 8 | temp[5]) * 200.0 / (1 << 20) - 50;
}
static void aht10_init(const char *name)
{
rt_uint8_t temp[2] = {0, 0};
/* 查找I2C总线设备,获取I2C总线设备句柄 */
i2c_bus = (struct rt_i2c_bus_device *)rt_device_find(name);
if (i2c_bus == RT_NULL)
{
rt_kprintf("can't find %s device!
", name);
}
else
{
write_reg(i2c_bus, AHT10_NORMAL_CMD, temp);
rt_thread_mdelay(400);
temp[0] = 0x08;
temp[1] = 0x00;
write_reg(i2c_bus, AHT10_CALIBRATION_CMD, temp);
rt_thread_mdelay(400);
initialized = RT_TRUE;
}
}
static void i2c_aht10_sample(int argc, char *argv[])
{
float humidity, temperature;
char name[RT_NAME_MAX];
humidity = 0.0;
temperature = 0.0;
if (argc == 2)
{
rt_strncpy(name, argv[1], RT_NAME_MAX);
}
else
{
rt_strncpy(name, AHT10_I2C_BUS_NAME, RT_NAME_MAX);
}
if (!initialized)
{
/* 传感器初始化 */
aht10_init(name);
}
if (initialized)
{
/* 读取温湿度数据 */
read_temp_humi(&temperature, &humidity);
rt_kprintf("read aht10 sensor humidity : %d.%d %%
", (int)humidity, (int)(humidity * 10) % 10);
rt_kprintf("read aht10 sensor temperature: %d.%d
", (int)temperature, (int)(temperature * 10) % 10);
}
else
{
rt_kprintf("initialize sensor failed!
");
}
}
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(i2c_aht10_sample, i2c aht10 sample);
运行效果
输入指令
总结
代码部分都是rt这边配置完毕,自己不用写多少代码就行。