#include "ADS1256.h"
#include "spi.h"

unsigned int sum;
long ulResult;
long double ldVolutage;

int ads_cnt = 0;

int ao_num = 0;

/************************************************
函数名称 ： ads1256_write_byte
功    能 ： SPI写读一个字节
参    数 ： Byte ---- 数据
返 回 值 ： Byte ---- 数据
*************************************************/
uint8_t ads1256_write_byte( uint8_t Byte )
{
	uint8_t i;

	ADS1256_SCK(0);
	
	for(i = 0;i < 8;i++)
	{
		ADS1256_SCK(1);
		delay_us(1);       // 空等待
		
		if(Byte & 0x80)
		{
			ADS1256_MOSI(1);
		}
		else
		{
			ADS1256_MOSI(0);
		}
		
		Byte <<= 1;
		delay_us(1);       // 空等待
		ADS1256_SCK(0);
		delay_us(2);       // 空等待
		Byte |= ADS1256_MISO;
	}
	
	return Byte;
}

/************************************************
函数名称 ： ads1256_read_byte
功    能 ： SPI只读一个字节
参    数 ： 无
返 回 值 ： temp ---- 数据
*************************************************/
uint8_t ads1256_read_byte(void)
{
	uint8_t i;
	uint8_t temp = 0;

	ADS1256_SCK(0);
	
	for(i = 0;i < 8;i++)
	{
		ADS1256_SCK(1);
		delay_us(1);       // 空等待
		temp <<= 1;
		
		temp |= ADS1256_MISO;
		
		delay_us(1);       // 空等待
		ADS1256_SCK(0);
		delay_us(2);       // 空等待
	}
	
	return temp;
}


//-----------------------------------------------------------------//
//	功    能：ADS1256 写数据
//	入口参数: /
//	出口参数: /
//	全局变量: /
//	备    注: 向ADS1256中地址为regaddr的寄存器写入一个字节databyte
//-----------------------------------------------------------------//
void ADS1256WREG(unsigned char regaddr,unsigned char databyte)
{
	unsigned char cmd;
	ADS1256_NSS(0);
	while(ADS1256_DRDY);//当AD2_DRDY为低时才能写寄存器
	//向寄存器写入数据地址
	cmd = ADS1256_CMD_WREG|(regaddr & 0x0F);
	ads1256_write_byte(cmd);
    //写入数据的个数n-1
	cmd = 0x00;
	ads1256_write_byte(cmd);
    //向regaddr地址指向的寄存器写入数据databyte
    ads1256_write_byte(databyte);
	ADS1256_NSS(0);
}

//初始化ADS1256
void ads1256_init(void)
{
	ADS1256_NSS(0);
	ADS1256_PDWN(1);
	ADS1256WREG(ADS1256_STATUS,0x06);// 高位在前、自校准、缓冲
	ADS1256WREG(ADS1256_MUX,ADS1256_MUXP_AIN0 | ADS1256_MUXN_AINCOM);// 初始化端口A0为‘+’，AINCOM位‘-’
	ADS1256WREG(ADS1256_ADCON,0x00);// 放大倍数1
	ADS1256WREG(ADS1256_DRATE,ADS1256_DRATE_1000SPS);// 数据1000sps
	ADS1256WREG(ADS1256_IO,0x00);
	ads1256_write_byte(ADS1256_CMD_SELFCAL);
	ADS1256_NSS(0);
}

//读取AD值
long double ADS1256ReadData(uint8_t channel)  
{
  unsigned char cmd;
  unsigned char data[3];
  while(ADS1256_DRDY)
	{
		ads_cnt++;
		if(ads_cnt >= 65535)
		{
			ads_cnt = 0;
			return ldVolutage;
		}
			
	}//当AD2_DRDY为低时才能写寄存器;
  
  //切换通道
  //注意：本次写入的新通道在下次读取时才会生效，本次读到的是上一次的值
  switch(channel)
  {
    case 0:
      ADS1256WREG(ADS1256_MUX, ADS1256_MUXP_AIN0 | ADS1256_MUXN_AINCOM);
      break;
    case 1:
      ADS1256WREG(ADS1256_MUX, ADS1256_MUXP_AIN1 | ADS1256_MUXN_AINCOM);
      break; 
    case 2:
      ADS1256WREG(ADS1256_MUX, ADS1256_MUXP_AIN2 | ADS1256_MUXN_AINCOM);
      break; 
    case 3:
      ADS1256WREG(ADS1256_MUX, ADS1256_MUXP_AIN3 | ADS1256_MUXN_AINCOM);
      break; 
    case 4:
      ADS1256WREG(ADS1256_MUX, ADS1256_MUXP_AIN4 | ADS1256_MUXN_AINCOM);
      break; 
    case 5:
      ADS1256WREG(ADS1256_MUX, ADS1256_MUXP_AIN5 | ADS1256_MUXN_AINCOM);
      break; 
    case 6:
      ADS1256WREG(ADS1256_MUX, ADS1256_MUXP_AIN6 | ADS1256_MUXN_AINCOM);
      break; 
    case 7:
      ADS1256WREG(ADS1256_MUX, ADS1256_MUXP_AIN7 | ADS1256_MUXN_AINCOM);
      break; 
  }

  ADS1256_NSS(0);
  cmd = ADS1256_CMD_SYNC;
  ads1256_write_byte(cmd);
  cmd = ADS1256_CMD_WAKEUP;
  ads1256_write_byte(cmd);

  //发送单次读命令
  cmd = ADS1256_CMD_RDATA;
  ads1256_write_byte(cmd);
  delay_us(5);

  //读24位数据
  data[0] = ads1256_read_byte();
  data[1] = ads1256_read_byte();
  data[2] = ads1256_read_byte();
  sum = (unsigned int)(data[0]<<16)|(data[1]<<8)|data[2];
  delay_us(5);

  //单位转换为mV (VREF=2.5V) 
  ulResult = sum;
  if(ulResult & 0x800000)
  {
    ulResult =  ~(unsigned long)ulResult;
    ulResult &= 0x7fffff;
    ulResult += 1;
    ulResult =  -ulResult;
    ldVolutage = (long double)ulResult*0.000596046518808;
  }
  else 
    ldVolutage = (long double)ulResult*0.000596046518808;

  return ldVolutage;
}


void ads1256_get_data(void)
{
	switch(ao_num)
	{
		//执行机构附件测试 -120 其余装置可改为 -150 视具体情况而定
		case 0 :
		{
			InputReg[0] = (uint16_t)(((ADS1256ReadData(1) * 10) / 0.82 - 150) / 0.99);//阀位反馈（0-25000uA） - 140) / 0.99
			ao_num = 1;
		}
		break;
		
		case 1 :
		{
			InputReg[1] = (uint16_t)(((ADS1256ReadData(2) * 10) / 0.82 - 150) / 0.99);//阀前压力（0-25000uA） - 150) / 0.99
			ao_num = 2;
		}
		break;
			
		case 2 :
		{
			InputReg[2] = (uint16_t)(((ADS1256ReadData(3) * 10) / 0.82 - 150) / 0.99);//ADS1256数据备用（0-25000uA） - 140) / 0.99
			ao_num = 3;
		}
		break;
		
		case 3 :
		{			
			InputReg[3] = (uint16_t)(((ADS1256ReadData(4) * 10) / 0.82 - 150) / 0.99);//ADS1256数据备用（0-25000uA） - 150) / 0.99
			ao_num = 4;
		}
		break;
		
		case 4 :
		{
			InputReg[4] = (uint16_t)(((ADS1256ReadData(5) * 10) / 0.82 - 150) / 0.99);//ADS1256数据备用（0-25000uA） - 130) / 0.99
			ao_num = 5;
		}
		break;
		
		case 5 :
		{
			InputReg[5] = (uint16_t)(((ADS1256ReadData(6) * 10) / 0.82 - 150) / 0.99);//ADS1256数据备用（0-25000uA） - 140) / 0.99
			ao_num = 6;
		}
		break;
		
		case 6 :
		{
			InputReg[6] = (uint16_t)(((ADS1256ReadData(7) * 10) / 0.82 - 150) / 0.99);//ADS1256数据备用（0-25000uA） - 130) / 0.99
			ao_num = 7;
		}
		break;
		
		case 7 :
		{
			InputReg[7] = (uint16_t)(((ADS1256ReadData(0) * 10) / 0.82 - 150) / 0.99);//ADS1256数据备用（0-25000uA） - 150) / 0.99
			ao_num = 0;
		}
		break;
	}
}