SPI

rtthread spi怎么用

发布于 2018-08-21 16:36:48 浏览：8573 订阅该版

10 个回答

aozima 2018-08-21

调网络不抓包，调I2C等时序不上逻辑分析仪，就像电工不用万用表！多用整理的好的文字，比截图更省流量，还能在整理过程中思考。

啊暴哥 2018-08-21

这家伙很懒，什么也没写！

啊暴哥 2018-08-21

这家伙很懒，什么也没写！

```
static void spi_thread_entry(void *parameter)
{
	struct rt_spi_configuration spi3_config;
	struct rt_spi_device spi3_device;
	rt_device_t spi3_dev = RT_NULL;
	rt_uint8_t buffer[15];
	
	rt_uint8_t i;
	rt_uint16_t len;
	spi3_dev = rt_device_find("spi3");
	if(spi3_dev != RT_NULL)
	{
//		rt_device_open(spi3_dev,RT_DEVICE_OFLAG_RDWR|RT_DEVICE_FLAG_DMA_RX|RT_DEVICE_FLAG_DMA_TX);
		rt_device_open(spi3_dev,RT_DEVICE_OFLAG_RDWR);
	}
	else
	{
		rt_kprintf("spi3 error!!!\r\n");
	}
	rt_pin_mode(SPI3_CE,PIN_MODE_OUTPUT);
	rt_spi_bus_attach_device(&spi3_device,"spi3","spi30",RT_NULL);
	
	spi3_config.mode = RT_SPI_MSB //高位在前
										|RT_SPI_SLAVE //外部设备为从设备
										|RT_SPI_MODE_2;//时钟前沿采集，空闲高电平
	spi3_config.data_width = 8;//数据宽度为8
	spi3_config.max_hz = 36000000;//最大速度为36M
	
	rt_spi_configure(&spi3_device,&spi3_config);
	
	while(1)
	{
		rt_pin_write(SPI3_CE,PIN_LOW);
		len=rt_spi_recv(&spi3_device,buffer,12);
		rt_pin_write(SPI3_CE,PIN_HIGH);
		if(len == 12)
		{
			rt_kprintf("The data is:");
			for(i=0;i<12;i++)
			{
				rt_kprintf("%x ",buffer[i]);
			}
			rt_kprintf("\r\n");
		}
		rt_thread_delay(10);
	}
}
```

这样子写有什么问题吗

yqiu 2018-08-21

这家伙很懒，什么也没写！

whj467467222 认证专家 2018-08-22

开源，分享，交流，共同进步

啊暴哥 2018-08-22

这家伙很懒，什么也没写！

之前没有看清楚SPI学习笔记的内容，把SPI设备和SPI总线搞混了，一直报总线错误；
实测不用查找SPI设备，不用代码拉高拉低cs引脚，都可以获取spi总线上的数据。
下面是我写的代码，使用了spi3，我用的是官网里《RTThread快速入门实例程序教程》里的程序写的，要自己手动添加spi3相关的驱动代码和文件。

```
#include "spi_test.h"

static rt_thread_t nrf_spi_thread = RT_NULL;
static rt_device_t spi3_dev = RT_NULL;
static struct rt_spi_device spi3_device;

//spi cs引脚的结构体
struct spi_cs_pin_struct{
	uint16_t spi_cs;
}spi_cs_pin;

//spi3初始化
rt_err_t spi3_init()
{
	rt_err_t result;
	struct rt_spi_configuration spi3_config;
	
	
//	spi3_dev = rt_device_find("spi3");//寻找spi3设备
//	if(spi3_dev != RT_NULL)
//	{
//		//打开spi3设备，可读可写
////		rt_device_open(spi3_dev,RT_DEVICE_OFLAG_RDWR|RT_DEVICE_FLAG_DMA_RX|RT_DEVICE_FLAG_DMA_TX);
//		result = rt_device_open(spi3_dev,RT_DEVICE_OFLAG_RDWR);
//		if(result == RT_ERROR)
//		{
//			rt_kprintf("spi3 open error\r\n");
//			return RT_ERROR;
//		}
//	}
//	else
//	{
//		rt_kprintf("spi3 find error\r\n");
//		return RT_ERROR;
//	}
	
	//配置cs引脚
	spi_cs_pin.spi_cs = SPI3_CE;
	rt_pin_mode(spi_cs_pin.spi_cs,PIN_MODE_OUTPUT);
	rt_pin_write(spi_cs_pin.spi_cs,PIN_HIGH);
	
	//挂接设备到spi总线
	if(rt_spi_bus_attach_device(&spi3_device,"spi30","spi3",&spi_cs_pin)==RT_ERROR)
	{
		rt_kprintf("spi3 bus error\r\n");
		return RT_ERROR;
	}
	
	//spi3配置
	spi3_config.mode = RT_SPI_MSB //高位在前
										|RT_SPI_MASTER //单片机为主设备
										|RT_SPI_MODE_3;//时钟前沿采集，空闲高电平
	spi3_config.data_width = 8;//数据宽度为8
	spi3_config.max_hz = 36000000;//最大速度为36M
	
	if(rt_spi_configure(&spi3_device,&spi3_config)==RT_ERROR)
	{
		rt_kprintf("spi3 config error\r\n");
		return RT_ERROR;
	}
	
	return RT_EOK;
}

//与nrf芯片通讯线程
static void nrf_spi_entry(void *parameter)
{
	rt_uint8_t buffer[12]={0};
	rt_uint8_t len,i;
	while(1)
	{
//		rt_pin_write(SPI3_CE,PIN_LOW);
		len=rt_spi_recv(&spi3_device,buffer,12);
//		rt_pin_write(SPI3_CE,PIN_HIGH);
		rt_kprintf("Data is:\r\n");
		if(len == 12)
		{
			for(i=0;i<12;i++)
			{
				rt_kprintf("%X ",buffer[i]);
			}
			rt_kprintf("\r\n");
		}
		rt_thread_delay(10);
	}
}

rt_err_t NRF_SPI_INIT()
{
	if(spi3_init()==RT_EOK)
	{
		rt_kprintf("spi3 is ready!!!\r\n");
		nrf_spi_thread = rt_thread_create("nrf_spi",nrf_spi_entry,RT_NULL,1024,10,10);
		if(nrf_spi_thread != RT_NULL)
		{
			rt_thread_startup(nrf_spi_thread);
		}
		else
			return RT_ERROR;
	}
	else
		return RT_ERROR;
	return RT_EOK;
}

/* 如果设置了RT_SAMPLES_AUTORUN，则加入到初始化线程中自动运行 */
#if defined (NRF_SPI_INIT_AUTORUN) && defined(RT_USING_COMPONENTS_INIT)
    INIT_APP_EXPORT(NRF_SPI_INIT);
#endif
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(NRF_SPI_INIT, NRF_SPI_THREAD open);

```