ADS1115-Q1: Read the output value is 0

/************************************************************
FileName:       bsp_iic.h
Author:         liamtsen  
Date:           2019/03/07
Description:    IIC����
***********************************************************/
#include "global.h"

//IO��������
#define ADC_SDA_IN()   SystemIoModeSetIn(GPIOB,RCC_AHB1Periph_GPIOB,GPIO_Pin_11)
#define ADC_SDA_OUT()  SystemIoModeSetOut(GPIOB,RCC_AHB1Periph_GPIOB,GPIO_Pin_11)
#define ADC_SCL_OUT()  SystemIoModeSetOut(GPIOB,RCC_AHB1Periph_GPIOB,GPIO_Pin_10)
//IO��������	 
#define ADC_SCL_H    GPIO_SetBits(GPIOB, GPIO_Pin_10)   //SCL
#define ADC_SCL_L    GPIO_ResetBits(GPIOB, GPIO_Pin_10)   //SCL

#define ADC_SDA_H    GPIO_SetBits(GPIOB, GPIO_Pin_11)   //SDA
#define ADC_SDA_L    GPIO_ResetBits(GPIOB, GPIO_Pin_11)   //SDA


#define ADC_READ_SDA   GPIO_ReadInputDataBit(GPIOB, GPIO_Pin_11)



//ʱ���õ�48M��һ����������1/48000000s
void ADC_delay_us(u32 time)
{
  u32 delay=0;
  while(time>0)
  {
    for(delay=0;delay<48;delay++);
    time--;
  }
}


//��ʼ��IIC
void ADC_I2C_Init(void)
{	
  ADC_SDA_OUT();
  ADC_SDA_H;
  ADC_SCL_OUT();
  ADC_SCL_H;
}

//����IIC��ʼ�ź�
void ADC_Start(void)
{
	ADC_SDA_OUT();
	ADC_SDA_H;
	ADC_delay_us(4);
	ADC_SCL_H;
	ADC_delay_us(4);
 	ADC_SDA_L;
	ADC_delay_us(4);
	ADC_SCL_L;
	ADC_delay_us(4);
}	  
//����IICֹͣ�ź�
void ADC_Stop(void)
{
	ADC_SDA_OUT();//sda�����
	ADC_SDA_L;
 	ADC_delay_us(4);
	ADC_SCL_H;
	ADC_delay_us(4);
	ADC_SDA_H;
	ADC_delay_us(4);							   	
}
//�������ݺ󣬵ȴ�Ӧ���źŵ���
//����ֵ��1������Ӧ��ʧ�ܣ�IICֱ���˳�
//        0������Ӧ��ɹ���ʲô������
u8 ADC_Wait_Ack(void)
{
    u8 ucErrTime = 50;
	ADC_SDA_OUT();//sda�����
    ADC_SDA_H;
	ADC_delay_us(4);
	
    ADC_SCL_H;
	ADC_delay_us(4);
	
    ADC_SDA_IN();
	while(ADC_READ_SDA)
	{
		ucErrTime --;
		if(!ucErrTime)
		{
			ucErrTime = 0xff;
			break;
		}
	}
    ADC_SCL_L;
    ADC_delay_us(4);
    return(ucErrTime);  
} 

//����ACKӦ��
void ADC_Ack(void)
{
    ADC_SDA_OUT();
    ADC_SDA_L;
    ADC_delay_us(4);
    ADC_SCL_H;
    ADC_delay_us(4);
    ADC_SCL_L;
    ADC_delay_us(4);
}
//������ACKӦ��		    
void ADC_NAck(void)
{
    ADC_SDA_OUT();
    ADC_SDA_H;
    ADC_delay_us(4);
    ADC_SCL_H;
    ADC_delay_us(4);
    ADC_SCL_L;
    ADC_delay_us(4);
}
//IIC����һ���ֽ�
//���شӻ�����Ӧ��
//1����Ӧ��
//0����Ӧ��			  
void ADC_Send_Byte(u8 txd)
{
	u8 t = 8;
	ADC_delay_us(4);
	ADC_SDA_OUT(); 	    
	while(t--)
	{              
		if((txd&0x80)!=0)
			ADC_SDA_H;
		else
			ADC_SDA_L;
		ADC_delay_us(4);

		ADC_SCL_H;
		ADC_delay_us(4); 
		
		ADC_SCL_L;	
		ADC_delay_us(4);
		txd<<=1;
	}	 
} 	    

//��1���ֽڣ�ack=1ʱ������ACK��ack=0������nACK   
u8 ADC_Read_Byte(void)
{
	unsigned char i,receive=0;
	ADC_SDA_IN();
	for(i=8;i!=0;i--)
	{
		ADC_SCL_H;
		ADC_delay_us(4);

		receive<<=1;
		if(ADC_READ_SDA)
			receive|=0x01;
		else
			receive&=0xFE;

		ADC_SCL_L; 
		ADC_delay_us(4);
	}
	return(receive);
}

void Ads1115_Config(void)
{
	ADC_Start();  
	ADC_Send_Byte(0x92);
	ADC_Wait_Ack();
	ADC_Send_Byte(0x01);
	ADC_Wait_Ack(); 

	ADC_Send_Byte(0x84);
	ADC_Wait_Ack();  
	ADC_Send_Byte(0x83);
	ADC_Wait_Ack();

	ADC_Stop();//����һ��ֹͣ���� 
	ADC_delay_us(200);
}

void Ads1115_PointRegister(void)
{
	ADC_Start();  
	ADC_Send_Byte(0X92);	//����������ַ0X30,д����  
	ADC_Wait_Ack();	   
	ADC_Send_Byte(0x00);	//���͵͵�ַ
	ADC_Wait_Ack();
	ADC_Stop();				//����һ��ֹͣ���� 
	ADC_delay_us(200);
}

u16 Ads1115_ReadData(void)
{
	u8 ReadDataBuf[5];
	u16 ADtemp; 
	ADC_Start();  
	ADC_Send_Byte(0X93);	//����������ַ0X30,д����  
	ADC_Wait_Ack();

	ReadDataBuf[0] = ADC_Read_Byte();
	ADC_Ack();
	ReadDataBuf[1] = ADC_Read_Byte(); 
	ADC_NAck();
	
	ADC_Stop();				//����һ��ֹͣ���� 
	ADC_delay_us(200);
	ADtemp = ReadDataBuf[0];
	ADtemp <<= 8;
	ADtemp += ReadDataBuf[1];
	return(ADtemp);
}