SM5852微压传感器，IIC写器件地址时得不到应答是怎么回事呀？

yts1213 · 发表于 2015-11-10 16:33:30

[mw_shl_code=c,true]#include "SM5852.h" unsigned char test1; /***************************************************************************** //函数: IICDelay //功能: 本文件内的延时程序调用 *****************************************************************************/ void IICDelay(volatile unsigned char DelayCount) { while(DelayCount --) { ; //CLEARDOG; } } /***************************************************************************** //函数: I2C_Start //功能: IIC驱动程序之起始位 *****************************************************************************/ void I2C_Start(void) { Sensor_SDA_OUT; Sensor_SDA = 1; Sensor_SCL = 1; IICDelay(5); Sensor_SDA = 0; IICDelay(5); Sensor_SCL = 0; } /***************************************************************************** //函数: I2C_Stop //功能: IIC驱动程序之停止位 *****************************************************************************/ void I2C_Stop(void) { Sensor_SDA_OUT; Sensor_SCL = 0; Sensor_SDA = 0; IICDelay(5); Sensor_SCL = 1; IICDelay(5); Sensor_SDA = 1; IICDelay(5); } /***************************************************************************** //函数: I2C_WaitACK //功能: IIC驱动程序之等待ACK *****************************************************************************/ void I2C_WaitACK(void) { unsigned char errtime; errtime = 40; Sensor_SDA_OUT; Sensor_SDA = 1; IICDelay(10); //读ACK Sensor_SCL = 1; IICDelay(10); Sensor_SDA_IN; while(Sensor_SDA) { errtime --; if(!errtime) { I2C_Stop(); test1 = 4; break; } } Sensor_SCL = 0; Sensor_SDA_OUT; IICDelay(5); } /***************************************************************************** //函数: I2C_SndAck //功能: IIC驱动程序之主机发送应答 *****************************************************************************/ void I2C_SndAck(void) { Sensor_SDA_OUT; Sensor_SDA = 0; IICDelay(5); Sensor_SCL = 1; IICDelay(5); Sensor_SCL = 0; } /***************************************************************************** //函数: I2C_SndNoAck //功能: IIC驱动程序之主机发送非应答 *****************************************************************************/ void I2C_SndNoAck(void) { Sensor_SDA_OUT; Sensor_SDA=1; IICDelay(5); Sensor_SCL=1; IICDelay(5); Sensor_SCL=0; } /***************************************************************************** //函数: I2C_WriteByte //功能: IIC写字节 *****************************************************************************/ void I2C_WriteByte(unsigned char data) { unsigned char i; Sensor_SDA_OUT; for(i = 0; i < 8; i++)//以最高为传输数据 { if(data & 0x80) { Sensor_SDA = 1; } else { Sensor_SDA = 0; } data <<= 1; Sensor_SCL = 1; IICDelay(5); Sensor_SCL = 0; } I2C_WaitACK(); //如果通讯错误,将不能接收到ack } /***************************************************************************** //函数: I2C_ReadByte //功能: IIC读字节 *****************************************************************************/ unsigned char I2C_ReadByte(void) { unsigned char i,bytedata; Sensor_SDA_IN; for(i = 0; i < 8; i++)//以最高为传输数据 { Sensor_SCL = 1; bytedata <<= 1; bytedata |= Sensor_SDA; Sensor_SCL = 0; IICDelay(5); } Sensor_SDA_OUT; return(bytedata); } /***************************************************************************** //函数: InitSensor //功能: 初始化传感器 *****************************************************************************/ void InitSensor(void) { Sensor_SCL_OUT; //传感器时钟线 Sensor_SCL = 1; //传感器时钟线 Sensor_SDA_OUT; //传感器数据线 Sensor_SDA = 1; //传感器数据线 } /***************************************************************************** //函数: Sensor_ReadOneByte //功能: 从片内指定地址读一个字节数据 *****************************************************************************/ unsigned char Sensor_ReadOneByte(unsigned char RegAddr) { unsigned char mdata; I2C_Start(); I2C_WriteByte(ADDRESS_SM5852_WR); I2C_WriteByte(RegAddr); I2C_Start(); I2C_WriteByte(ADDRESS_SM5852_RE); mdata = I2C_ReadByte(); I2C_SndNoAck(); I2C_Stop(); //停止I2C IICDelay(100);//此处延时根据实际情况，如果不延时，可能会不正常 return(mdata); } /***************************************************************************** //函数: Sensor_ReadMultiByte //功能: 从片内指定地址读出多个字节的数据 *****************************************************************************/ void Sensor_ReadMultiByte(unsigned char ucStartAddress,volatile unsigned char *datebuffer,unsigned char ucByteCounter) { I2C_Start(); I2C_WriteByte(ADDRESS_SM5852_WR); I2C_WriteByte(ucStartAddress); I2C_Start(); I2C_WriteByte(ADDRESS_SM5852_RE); while(-- ucByteCounter) { *datebuffer ++= I2C_ReadByte(); I2C_SndAck(); } *datebuffer = I2C_ReadByte(); I2C_SndNoAck(); I2C_Stop(); IICDelay(200);//此处延时根据实际情况，如果不延时，可能会不正常 } [/mw_shl_code]