如何使用外部AD芯片AD7792，只会在裸机上用

发布于 2019-06-12 09:46:59 浏览：2164 订阅该版

9 个回答

zhangjun 2019-06-12

这家伙很懒，什么也没写！

morning559 2019-06-12

这家伙很懒，什么也没写！

zailiy 2019-06-12

这家伙很懒，什么也没写！

可以参考下这个，我们的项目中也是用AD7792。测试正常

int rt_ad7792_init(void)
{	
	rt_hw_spi_device_attach("spi1",SPI_BUS_NAME,GPIOA,GPIO_PIN_4);
	
	spi_bus = (struct rt_spi_device *)rt_device_find(SPI_BUS_NAME);
	if (spi_bus == RT_NULL)
	{
		LOG_D("\nspi_bus %s for ad7792 not found!\n", SPI_BUS_NAME);
		return -RT_ENOSYS;
	}
	if (rt_device_open(&spi_bus->parent, RT_NULL) != RT_EOK)
	{
		LOG_D("\nspi_bus %s for ad7792 opened failed!\n", SPI_BUS_NAME);
		return -RT_EEMPTY;
	}

/* config spi */
  {
        struct rt_spi_configuration cfg;
        cfg.data_width = 8;
        cfg.mode = RT_SPI_MODE_3 | RT_SPI_MSB; /* SPI Compatible: Mode 0 and Mode 3 */
        cfg.max_hz = 1000 * 1000; /* 1MHz */
        rt_spi_configure(spi_bus, &cfg);
  }
	LOG_D("ad7792 attach to spi20.");

return RT_EOK;
}
INIT_COMPONENT_EXPORT(rt_ad7792_init);

int ad7792_set_amp(rt_uint8_t amp)
{
	uint8_t send_buffer[6];
  if(spi_bus == RT_NULL)
	{
		LOG_E("SPI BUS ERROR.");
		return 0;
	}
  send_buffer[0] = 0x10;     //准备写配置寄存器
  send_buffer[1] = amp;      //配置为双极性，增益8
	send_buffer[2] = 0x90 | ADC_CH1; //内部参考，缓冲使能
	
	send_buffer[3] = 0x08;
  send_buffer[4] = 0x00;
  send_buffer[5] = 0x01;
	
	rt_spi_send(spi_bus, send_buffer, 6);
	
	return 0;
}
	
int get_wave(rt_int16_t *wave,rt_uint16_t length)
{
	uint8_t send_buffer[5];
  uint8_t recv_buffer[2];
	int ResetTime;
	unsigned short n,i;

for(i=0;i<length;i++)
	{
		recv_buffer[0] = 0;		
		send_buffer[0] = 0x40;  //write to Communication register.The next step is to read from Status register.
    rt_spi_send_then_recv(spi_bus,
                          send_buffer, 1,
                          recv_buffer, 1);
		ResetTime = 0;

while((recv_buffer[0]&0x80) == 0x80)//wait for the end of convertion by polling the status register RDY bit
		{
			send_buffer[0] = 0x40;            //write to Communication register.The next step is to read from Status register.
			rt_spi_send_then_recv(spi_bus,
														send_buffer, 1,
														recv_buffer, 1);
			ResetTime++;
			rt_thread_mdelay(1);
			if(ResetTime > 10)
			{
				LOG_E("ADC ERROR!");
				break;
			}
		}
    if(ResetTime  >= 10)
		{
			break;
		}
		send_buffer[0] = 0x58;  //write to Communication register.The next step is to read from Data register.
		rt_spi_send_then_recv(spi_bus,
													send_buffer, 1,
													recv_buffer, 2);
		
		n = recv_buffer[0];
		wave[i] = ((n<<8) | recv_buffer[1]) - 0x8000;
	}
	
	send_buffer[0] = 0x08;
  send_buffer[1] = 0x60;
  send_buffer[2] = 0x00;

rt_spi_send(spi_bus, send_buffer, 3);

LOG_D("adc sample dots : %d \n",i);
	return (i); //PresstureVal*1.49-38.7;//套压测量值，单位0.01Bar
}