#ifndef _SHT11_H_
#define _SHT11_H_

#define SHT_TEMP_CMD		0x03
#define SHT_HUMI_CMD		0x05
#define SHT_WR_STAT_CMD		0x06
#define SHT_RD_STAT_CMD		0x07
#define SHT_RST_CMD			0x1E

#define SHT_TIMOUT_CNT		60000

#define SHT_ACK				0
#define SHT_NACK			1

typedef enum
{
	SHT_RES_T14_H12,
	SHT_RES_T12_H8
} sht_res_t;

#if V_CPUx10 == 50
#define SHT_100xD1			4000
#endif
#if V_CPUx10 == 45
#define SHT_100xD1			3975
#endif
#if V_CPUx10 == 35
#define SHT_100xD1			3966
#endif
#if V_CPUx10 == 33
#define SHT_100xD1			3964
#endif
#if V_CPUx10 == 30
#define SHT_100xD1			3960
#endif

uint8_t sht_dat_buf;
uint8_t sht_dat[3];
sht_res_t sht_res = SHT_RES_T14_H12;

uint8_t inq_temp_flag = 0;
uint8_t inq_humi_flag = 0;
uint8_t inq_all_flag = 0;

typedef enum
{
	SHT_INQ_NONE,
	SHT_INQ_TEMP,
	SHT_INQ_HUMI
} sht_inq_t;

sht_inq_t sht_inq = SHT_INQ_NONE;

typedef enum
{
	SHT_RESP_OK,
	SHT_RESP_NOT_FOUND,
	SHT_RESP_TIMEOUT,	
} sht_response_t;

sht_response_t sht_response = SHT_RESP_OK;

uint8_t volatile sht_waiting = 0;
uint8_t time_500ms_buf1 = 0;
uint8_t time_500ms_buf2 = 0;

#define THSensGetWaiting()		(sht_waiting)
#define THSensGetResp()			(sht_response)

void THSensTempConv()
{
	uint16_t tempx100;
	tempx100 = sht_dat[0];
	tempx100 = tempx100 << 8;
	tempx100 = tempx100 | sht_dat[1];

	//SOt * d2
	if (sht_res == SHT_RES_T14_H12)
		tempx100 = tempx100*1;
	else
		tempx100 = tempx100*4;
	
	//SOt * d2 + d1
	tempx100 -= SHT_100xD1;
	sht_dat[0] = tempx100 / 100;
	sht_dat[1] = tempx100 % 100;
}

void THSensSetRes(sht_res_t res)
{
	sht_res = res;	
}

void THSensDelay() //For 3.3V app, maximum clock is 1MHz. For 5V app, it's 10MHz
{
#if F_CPU_MHZ > 10
	asm volatile("nop\n\t"::);
	asm volatile("nop\n\t"::);
	asm volatile("nop\n\t"::);
#endif
	asm volatile("nop\n\t"::);
	asm volatile("nop\n\t"::);
	asm volatile("nop\n\t"::);
	asm volatile("nop\n\t"::);
}

#define SHT_RD			Rdb(SHT_DAT_PINP,SHT_DAT_PIN)
#define SHT_RELES		Setb(SHT_DAT_PORT,SHT_DAT_PIN); Clrb(SHT_DAT_DPRT,SHT_DAT_PIN); THSensDelay()
#define SHT_LOW			Clrb(SHT_DAT_PORT,SHT_DAT_PIN); Setb(SHT_DAT_DPRT,SHT_DAT_PIN)
#define SHT_CLK1		THSensDelay(); Setb(SHT_CLK_PORT,SHT_CLK_PIN); THSensDelay()
#define SHT_CLK0		THSensDelay(); Clrb(SHT_CLK_PORT,SHT_CLK_PIN); THSensDelay()

void THSensStart()
{
	uint8_t volatile i;

	SHT_RELES;

	for (i=0; i<20; i++) //Reset connection
	{
		SHT_CLK1;
		SHT_CLK0;
	}

	SHT_CLK1;
	SHT_LOW;
	SHT_CLK0;
	SHT_CLK1;
	SHT_RELES;
	SHT_CLK0;
}

void THSensSendBit(uint8_t dat)
{
	if (dat)
	{
		SHT_RELES;
	}
	else
	{
		SHT_LOW;
	}

	SHT_CLK1;
	SHT_CLK0;
}

uint8_t THSensSendByte(uint8_t dat) //Return 1 when got ACK
{
	uint8_t i,ack;
	ack = 0;
	for (i=0; i<8; i++) 
	{
		THSensSendBit(Rdb(dat,7-i)); //Send MSB first
	}
	SHT_RELES;
	SHT_CLK1;
	if (SHT_RD == SHT_ACK)
		ack = 1;
	SHT_CLK0;
	return (ack);
}

void THSensRecvBit(uint8_t bitnum)
{
	SHT_CLK1;
	if (SHT_RD)
		Setb(sht_dat_buf,bitnum);
	SHT_CLK0;
}

void THSensRecvByte(uint8_t ack)
{
	uint8_t i;
	sht_dat_buf = 0;
	for (i=0; i<8; i++)
	{
		THSensRecvBit(7-i); //Recv MSB first
	}
	if (ack)
	{
		SHT_LOW;
	}
	else
	{
		SHT_RELES;
	}
	SHT_CLK1;
	SHT_CLK0;
	SHT_RELES;
}

void THSensInit()
{
	Setb(SHT_CLK_DPRT,SHT_CLK_PIN);
	Clrb(SHT_CLK_PORT,SHT_CLK_PIN); 
	SHT_RELES;
}

uint8_t THSensGet(uint8_t cmd)
{
	uint16_t i;
	uint8_t valid = 0;
	THSensStart();
	if (THSensSendByte(cmd))
	{
		THSensDelay();
		while (SHT_RD != 0);
		THSensDelay();
		for (i=0; i<3; i++)
		{
			THSensRecvByte(1);
			sht_dat[i] = sht_dat_buf;
		}
		SHT_RELES;
		valid = 1;
	}
	return (valid);
}

uint8_t THSensSendCMD(uint8_t cmd)
{
	uint8_t valid = 0;
	THSensStart();
	if (THSensSendByte(cmd))
		valid = 1;
	return (valid);
}

uint8_t THSensRecvDat()
{
	uint8_t i;
	uint8_t got_data = 0;
	if (SHT_RD == 0)
	{
		THSensDelay();
		for (i=0; i<3; i++)
		{
			THSensRecvByte(1);
			sht_dat[i] = sht_dat_buf;
		}
		SHT_RELES;
		got_data = 1;
	}
	return (got_data);
}

uint8_t THSensGetTemp()
{
	return (THSensGet(SHT_TEMP_CMD));
}

uint8_t THSensGetHumi()
{
	return (THSensGet(SHT_HUMI_CMD));
}

void THSensTest()
{
	if (THSensGetTemp())
	{
		THSensTempConv();
		//If temperature = 30.50
		//now sht_dat[0] = 30
		//and sht_dat[1] = 50

		//Use them as you wish!!!
	}
}

#endif