spi驱动cs 引脚注意事项RT_SPI_NO_CS

发布于 2021-10-23 20:41:42 浏览：1944 订阅该版

写一个铁电的驱动，半天一直通不了，最后发现是配置了RT_SPI_NO_CS。
导致通讯错误。故此记录一下. 
CS 还需要注意的就是不要专门配置成GPIO。
CUBEMX 配置
![image.png](https://oss-club.rt-thread.org/uploads/20211023/89a2e2645006f6168891384867cf4d17.png)

```c
//CS- PD0
int mb85rs16_spi_device_init()
{
    __HAL_RCC_GPIOD_CLK_ENABLE();
		rt_err_t res = RT_EOK;
    res = rt_hw_spi_device_attach("spi3", MB85RS16_SPI_DEVICE_NAME, GPIOD, GPIO_PIN_0);
	  if (res != RT_EOK)
		{
			LOG_E("mb85rs16 Failed to attach device %s\n", MB85RS16_SPI_DEVICE_NAME);
			return res;
		}
		fram_init();
}
INIT_COMPONENT_EXPORT(mb85rs16_spi_device_init);
int fram_init()
{
	  rt_err_t res = RT_EOK;
		spi_dev_mb85rs16 = (struct rt_spi_device *)rt_device_find(MB85RS16_SPI_DEVICE_NAME);
    if (!spi_dev_mb85rs16)
    {
        LOG_E("spi find run failed! cant't find %s device!\n", MB85RS16_SPI_DEVICE_NAME);
        return RT_NULL;
    }
		//Set device SPI Mode
		struct rt_spi_configuration cfg = {0};
		cfg.data_width = 8;
		cfg.mode = RT_SPI_MASTER |RT_SPI_MODE_0 | RT_SPI_MSB ;//| RT_SPI_NO_CS;// 
		cfg.max_hz = MB85RS16_SPICLOCK;
		rt_spi_configure(spi_dev_mb85rs16, &cfg);
		return res;
}
```