#include "AHT20.h"


MYI2C_Struct SENx = {0};



void  AHT20_Init(MYI2C_Struct *pst,uint16_t ReadTimMS,uint16_t xAddr)
{
	pst->Adrr =xAddr;
	pst->Step = SENSOR_IDLE;
	
	if(ReadTimMS>MinReadTim)pst->SetRTim=ReadTimMS;
	 else pst->SetRTim=MinReadTim;
}



uint8_t AHT20_READ_FUNC(MYI2C_Struct *pst,uint8_t device_addr,uint8_t register_addr,uint8_t *pDat,uint8_t len)
{
	uint8_t NoAck=0;
	
	if(register_addr)
	{
		/* Send STRAT condition a second time */  
		IIC_Start();	
		/* Send slave address for Write Regsiter */
		IIC_Send_Byte((device_addr<<1) + 0);
		/* Ack */
		if(IIC_Wait_Ack()==1)NoAck++; 
		 /*Send register_addr*/
		IIC_Send_Byte((register_addr));
		/* Ack */
		if(IIC_Wait_Ack()==1)NoAck++;

//   MYI2C_IIC_Stop(pst);
		IIC_Stop();
	}	
  /* Send STRAT condition a second time */  
	IIC_Start();	
  /* Send slave address for Read */
	IIC_Send_Byte((device_addr<<1)+1 );
  /* Ack */
	if(IIC_Wait_Ack()==1)NoAck++;
  /* While there is data to be read */
  while(len && NoAck==0 && len<MYI2C_Buffer_Size) // 
  {
		*pDat=IIC_Read_Byte(len-1);
		/*  Ack */
		pDat++;
		len--;           
  }
		/* Send STOP Condition */
		IIC_Stop();
 
  pst->ErrFlag=NoAck;
	
return NoAck;
}
 /*******************************************************************************
* Function Name  : 
* Description    : 
* Input          :  None
* Output         : None
* Return         :None
*******************************************************************************/
uint8_t AHT20_WRITE_FUNC(MYI2C_Struct *pst,uint8_t device_addr,uint8_t register_addr,uint8_t *pDat,uint8_t len)
{
unsigned int NoAck=0;	

  /* Send STRAT condition */
	IIC_Start();
  /* Send slave address for write */
	IIC_Send_Byte((device_addr<<1) + 0);
  /* ACK */
	if(IIC_Wait_Ack()==1)NoAck++;
   /* Send register_addr for read */
	IIC_Send_Byte((register_addr));
  /* ACK */
	if(IIC_Wait_Ack()==1)NoAck++;  	
  while(NoAck==0 && len && len<MYI2C_Buffer_Size)//
  {
		/* Send the byte to be written */
		IIC_Send_Byte(*pDat);
		/*  Acknowledgement */
		IIC_Wait_Ack();		
		pDat++;
		len--;	
  }
  /* Send STOP condition */
   IIC_Stop();
	
  pst->ErrFlag=NoAck;
	
return NoAck;
}





uint8_t  CheckCrc8(uint8_t *pDat,uint8_t Lenth)
{
	uint8_t crc = 0xff, i, j;

    for (i = 0; i < Lenth ; i++)
    {
        crc = crc ^ *pDat;
        for (j = 0; j < 8; j++)
        {
            if (crc & 0x80) crc = (crc << 1) ^ 0x31;
            else crc <<= 1;
        }
				pDat++;
    }
    return crc;
}

void  AHT20_Handle(MYI2C_Struct *pst)
{
	uint32_t	s32x;
	
	pst->timcnt += MYI2C_Tick;
	
	
	if(pst->timcnt>PowerOnTim && pst->Step==SENSOR_IDLE)
	{
		pst->Step=SENSOR_MEASURE;
		pst->SendByte[0]=0x33;
		pst->SendByte[1]=0x00;		
		AHT20_WRITE_FUNC(pst,pst->Adrr,0xAC, &pst->SendByte[0], 2);
	}
	else if(pst->timcnt>MeasureTim && pst->Step==SENSOR_MEASURE)
	{
		pst->Step=SENSOR_COMPLETE;
		AHT20_READ_FUNC(pst,pst->Adrr,0, &pst->ReadByte[0], 7);
		if(pst->ErrFlag==0)
		{
			if((CheckCrc8(&pst->ReadByte[0],6)==pst->ReadByte[6])&&((pst->ReadByte[0]&0x98) == 0x18))
			{
				s32x=pst->ReadByte[1];s32x=s32x<<8;s32x+=pst->ReadByte[2];s32x=s32x<<8;s32x+=pst->ReadByte[3];s32x=s32x>>4;				
				pst->RH=s32x;
				pst->RH=pst->RH*100/1048576;
				s32x=pst->ReadByte[3]&0x0F;s32x=s32x<<8;s32x+=pst->ReadByte[4];s32x=s32x<<8;s32x+=pst->ReadByte[5];		
				pst->T=s32x;
				pst->T=pst->T*200/1048576-50;
			}
		}
        else 
        {
			pst->RH=0;
			pst->T=0;
		}			
	}
	else if(pst->timcnt>pst->SetRTim)
	{
		pst->Step=SENSOR_IDLE;
		pst->timcnt=0;
	}
	
}