DS1302+D18B20+LCD1602+STC89C52模块化编程.7z

/********************************************************************* * 文件：D18B20.C * * 功能：D18B20驱动实现 * * 日期：20110803 * * 备注：12M晶振 * * 有事烧纸(QQ980445301)练手作品 * **********************************************************************/ #include <D18B20.H> /********************************************************************* 延时 延时精确值(据UV4汇编所生成src计算)： 参数us 延时(不)计调用时间 0 7 10 1 12 15 2 17 20 and so on... The equivalent polynomial function of this function is: 5*us+10(μs) ********************************************************************** MOV R7,#050H ;传参 1周期 ACALL _wait ;调用 2周期 _wait: ;函数入口 USING 0 ?C0001: MOV R6,AR7 DEC R7 ;1周期 MOV A,R6 JNZ ?C0001 ;2周期 RET ;函数返回 2周期 **********************************************************************/ void wait(unsigned char idata us) //延时分辨率: 5μs { while(us--); } /********************************************************************* 返回温度 **********************************************************************/ unsigned int get_Temp() { init_D18B20(); //初始化器件 write_Byte(0xCC); //Skip ROM(跳过ROM) write_Byte(0xBE); //读缓存命令 read_Temp(); //读取温度 return temperature; } /********************************************************************* 初始化器件 详见datasheet: Figure 11 Page 18. **********************************************************************/ void init_D18B20() { D18B20 = 1; _nop_(); //hold on a μs D18B20 = 0; wait(95); //delay 485 μs (480~960μs) D18B20 = 1; wait(20); //delay 110 μs (18B20 waits 15~60μs) if(D18B20 == 0) //主机释放总线后60μs 18B20发出应答0 { flag = 1; //detected } else { flag = 0; //not detect } wait(15); //delay 85 μs _nop_(); _nop_(); D18B20 = 1; } /********************************************************************* 写入单字节 Write Time Slots A write time slot is initiated when the host pulls the data line from a high logic level to a low logic level.(*1) There are two types of write time slots: Write 1 time slots and Write 0 time slots. All write time slots must be a minimum of 60 μs in duration with a minimum of a 1-μs recovery time between individual write cycles.(*2) The DS18B20 samples the DQ line in a window of 15 μs to 60 μs after the DQ line falls.(*3) If the line is high, a Write 1 occurs. If the line is low, a Write 0 occurs. For the host to generate a Write 1 time slot, the data line must be pulled to a logic low level and then released, allowing the data line to pull up to a high level within 15 μs after the start of the write time slot. For the host to generate a Write 0 time slot, the data line must be pulled to a logic low level and remain low for 60 μs. **********************************************************************/ void write_Byte(unsigned char idata wr) //write lsb first. { unsigned char idata i; for(i = 8; i; i--) { D18B20 = 0; //下降沿产生写时间隙(*1) _nop_(); D18B20 = wr & 0x01; //prepare for next bit wait(4); //delay 30 μs. 18B20在下降沿后15~60μs取样(*3) D18B20 = 1; //为下一循环的下降沿做准备 wr >>= 1; //next bit.使连续写2位间的间隙大于1us(*2) } } /********************************************************************* 读取单字节 Read Time Slots The host generates read time slots when data is to be read from the DS18B20. A read time slot is initiated when the host pulls the data line from a logic high level to logic low level.(*1) The data line must remain at a low logic level for a minimum of 1 μs;(*2) output data from the DS18B20 is valid for 15 μs after the falling edge of the read time slot.(*3) The host therefore must stop driving the DQ pin low in order to read its state 15 μs from the start of the read slot.(*4) By the end of the read time slot, the DQ pin will pull back high via the external pullup resistor. All read time slots must be a minimum of 60 μs in duration with a minimum of a 1-μs recovery time between individual read slots. **********************************************************************/ unsigned char read_Byte() //read lsb first. { unsigned char idata i, u = 0; for(i = 8; i; i--) { D18B20 = 0; //下降沿产生读时间隙(*1) u >>= 1; //prepare for next bit.(*2) D18B20 = 1; //释放总线(开漏输出特性)(*4) wait(1); //delay 15 μs if(D18B20 == 1) //下降沿产生后15μs内是18B20输出时间(*3) { u |= 0x80; //modify to 1 } } return u; } /********************************************************************* 读出多个字符(参数j：读取数量) **********************************************************************/ void read_Bytes(unsigned char idata j) { unsigned char idata i; p = temp_buff; //复位指针 for(i = j; i; i--) { *p = read_Byte(); p++; //下一个(肿么又係指针...) } } /********************************************************************* CRC校验(啥原理?)(cyclic redundancy check) **********************************************************************/ unsigned char CRC(unsigned char j) { unsigned char idata i, crc_data = 0; for(i = 0; i < j; i++) //查表校验 { crc_data = crcTable[crc_data ^ temp_buff[i]]; } return crc_data; //0：正确 } /********************************************************************* 读取温度 **********************************************************************/ void read_Temp() { read_Bytes(9); //读出全部缓存 if(CRC(9) == 0) //校验正确后计算温度值 { /************************************************************* The scratchpad is organized as eight bytes of memory. The first two bytes contain the LSB and the MSB of the measured temperature information, respectively. **************************************************************/ temperature = temp_buff[1] * 0x100 + temp_buff[0]; } } /********************************************************************* 配置报警限定值和分辨率 **********************************************************************/ void config() { init_D18B20(); //初始化器件 write_Byte(0xCC); //Skip ROM(跳过ROM) write_Byte(0x4E); //Write Scratchpad(写暂存存储器) write_Byte(0x19); //高�