普中51-单核-A2
STC89C52
Keil uVision V5.29.0.0
PK51 Prof.Developers Kit Version:9.60.0.0

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       移植自1-WIRE搜索算法

       串口部分见【51单片机快速入门指南】3.3：USART 串口通信
       DS18B20驱动程序见【51单片机快速入门指南】6.3：DS18B20 单总线数字温度计的多路读取

源码

OWSearch.c

#include "DS18B20.h"
#include <stdio.h>// TMEX API TEST BUILD DECLARATIONS
// long session_handle;
// END TMEX API TEST BUILD DECLARATIONS// definitions
#define FALSE 0
#define TRUE  1// method declarations
int  OWFirst();
int  OWNext();
int  OWVerify();
void OWTargetSetup(unsigned char family_code);
void OWFamilySkipSetup();
int  OWReset();
void OWWriteByte(unsigned char byte_value);
void OWWriteBit(unsigned char bit_value);
unsigned char OWReadBit();
int  OWSearch();
unsigned char docrc8(unsigned char value);// global search state
unsigned char ROM_NO[8];
int LastDiscrepancy;
int LastFamilyDiscrepancy;
int LastDeviceFlag;
unsigned char crc8;//--------------------------------------------------------------------------
// Find the 'first' devices on the 1-Wire bus
// Return TRUE  : device found, ROM number in ROM_NO buffer
//        FALSE : no device present
//
int OWFirst()
{// reset the search stateLastDiscrepancy = 0;LastDeviceFlag = FALSE;LastFamilyDiscrepancy = 0;return OWSearch();
}//--------------------------------------------------------------------------
// Find the 'next' devices on the 1-Wire bus
// Return TRUE  : device found, ROM number in ROM_NO buffer
//        FALSE : device not found, end of search
//
int OWNext()
{// leave the search state alonereturn OWSearch();
}//--------------------------------------------------------------------------
// Perform the 1-Wire Search Algorithm on the 1-Wire bus using the existing
// search state.
// Return TRUE  : device found, ROM number in ROM_NO buffer
//        FALSE : device not found, end of search
//
int OWSearch()
{int id_bit_number;int last_zero, rom_byte_number, search_result;int id_bit, cmp_id_bit;unsigned char rom_byte_mask, search_direction;// initialize for searchid_bit_number = 1;last_zero = 0;rom_byte_number = 0;rom_byte_mask = 1;search_result = 0;crc8 = 0;// if the last call was not the last oneif (!LastDeviceFlag){// 1-Wire resetif (!OWReset()){// reset the searchLastDiscrepancy = 0;LastDeviceFlag = FALSE;LastFamilyDiscrepancy = 0;return FALSE;}// issue the search command OWWriteByte(0xF0);  // loop to do the searchdo{// read a bit and its complementid_bit = OWReadBit();cmp_id_bit = OWReadBit();// check for no devices on 1-wireif ((id_bit == 1) && (cmp_id_bit == 1))break;else{// all devices coupled have 0 or 1if (id_bit != cmp_id_bit)search_direction = id_bit;  // bit write value for searchelse{// if this discrepancy if before the Last Discrepancy// on a previous next then pick the same as last timeif (id_bit_number < LastDiscrepancy)search_direction = ((ROM_NO[rom_byte_number] & rom_byte_mask) > 0);else// if equal to last pick 1, if not then pick 0search_direction = (id_bit_number == LastDiscrepancy);// if 0 was picked then record its position in LastZeroif (search_direction == 0){last_zero = id_bit_number;// check for Last discrepancy in familyif (last_zero < 9)LastFamilyDiscrepancy = last_zero;}}// set or clear the bit in the ROM byte rom_byte_number// with mask rom_byte_maskif (search_direction == 1)ROM_NO[rom_byte_number] |= rom_byte_mask;elseROM_NO[rom_byte_number] &= ~rom_byte_mask;// serial number search direction write bitOWWriteBit(search_direction);// increment the byte counter id_bit_number// and shift the mask rom_byte_maskid_bit_number++;rom_byte_mask <<= 1;// if the mask is 0 then go to new SerialNum byte rom_byte_number and reset maskif (rom_byte_mask == 0){docrc8(ROM_NO[rom_byte_number]);  // accumulate the CRCrom_byte_number++;rom_byte_mask = 1;}}}while(rom_byte_number < 8);  // loop until through all ROM bytes 0-7// if the search was successful thenif (!((id_bit_number < 65) || (crc8 != 0))){// search successful so set LastDiscrepancy,LastDeviceFlag,search_resultLastDiscrepancy = last_zero;// check for last deviceif (LastDiscrepancy == 0)LastDeviceFlag = TRUE;search_result = TRUE;}}// if no device found then reset counters so next 'search' will be like a firstif (!search_result || !ROM_NO[0]){LastDiscrepancy = 0;LastDeviceFlag = FALSE;LastFamilyDiscrepancy = 0;search_result = FALSE;}return search_result;
}//--------------------------------------------------------------------------
// Verify the device with the ROM number in ROM_NO buffer is present.
// Return TRUE  : device verified present
//        FALSE : device not present
//
int OWVerify()
{unsigned char rom_backup[8];int i,rslt,ld_backup,ldf_backup,lfd_backup;// keep a backup copy of the current statefor (i = 0; i < 8; i++)rom_backup[i] = ROM_NO[i];ld_backup = LastDiscrepancy;ldf_backup = LastDeviceFlag;lfd_backup = LastFamilyDiscrepancy;// set search to find the same deviceLastDiscrepancy = 64;LastDeviceFlag = FALSE;if (OWSearch()){// check if same device foundrslt = TRUE;for (i = 0; i < 8; i++){if (rom_backup[i] != ROM_NO[i]){rslt = FALSE;break;}}}elserslt = FALSE;// restore the search state for (i = 0; i < 8; i++)ROM_NO[i] = rom_backup[i];LastDiscrepancy = ld_backup;LastDeviceFlag = ldf_backup;LastFamilyDiscrepancy = lfd_backup;// return the result of the verifyreturn rslt;
}//--------------------------------------------------------------------------
// Setup the search to find the device type 'family_code' on the next call
// to OWNext() if it is present.
//
void OWTargetSetup(unsigned char family_code)
{int i;// set the search state to find SearchFamily type devicesROM_NO[0] = family_code;for (i = 1; i < 8; i++)ROM_NO[i] = 0;LastDiscrepancy = 64;LastFamilyDiscrepancy = 0;LastDeviceFlag = FALSE;
}//--------------------------------------------------------------------------
// Setup the search to skip the current device type on the next call
// to OWNext().
//
void OWFamilySkipSetup()
{// set the Last discrepancy to last family discrepancyLastDiscrepancy = LastFamilyDiscrepancy;LastFamilyDiscrepancy = 0;// check for end of listif (LastDiscrepancy == 0)LastDeviceFlag = TRUE;
}//--------------------------------------------------------------------------
// 1-Wire Functions to be implemented for a particular platform
//--------------------------------------------------------------------------//--------------------------------------------------------------------------
// Reset the 1-Wire bus and return the presence of any device
// Return TRUE  : device present
//        FALSE : no device present
//
int OWReset()
{// platform specific// TMEX API TEST BUILD
//   return (TMTouchReset(session_handle) == 1);return (!DS18B20_init());
}//--------------------------------------------------------------------------
// Send 8 bits of data to the 1-Wire bus
//
void OWWriteByte(unsigned char byte_value)
{// platform specific// TMEX API TEST BUILD
//   TMTouchByte(session_handle,byte_value);DS18B20_write_byte(byte_value);
}//--------------------------------------------------------------------------
// Send 1 bit of data to teh 1-Wire bus
//
void OWWriteBit(unsigned char bit_value)
{// platform specific// TMEX API TEST BUILD
//   TMTouchBit(session_handle,(short)bit_value);DS18B20_write_bit((short)bit_value);
}//--------------------------------------------------------------------------
// Read 1 bit of data from the 1-Wire bus 
// Return 1 : bit read is 1
//        0 : bit read is 0
//
unsigned char OWReadBit()
{// platform specific// TMEX API TEST BUILD
//   return (unsigned char)TMTouchBit(session_handle,0x01);return DS18B20_read_bit();
}// TEST BUILD
code unsigned char dscrc_table[] = {0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65,157,195, 33,127,252,162, 64, 30, 95,  1,227,189, 62, 96,130,220,35,125,159,193, 66, 28,254,160,225,191, 93,  3,128,222, 60, 98,190,224,  2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255,70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89,  7,219,133,103, 57,186,228,  6, 88, 25, 71,165,251,120, 38,196,154,101, 59,217,135,  4, 90,184,230,167,249, 27, 69,198,152,122, 36,248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91,  5,231,185,140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205,17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80,175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238,50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115,202,148,118, 40,171,245, 23, 73,  8, 86,180,234,105, 55,213,139,87,  9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22,233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168,116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53};//--------------------------------------------------------------------------
// Calculate the CRC8 of the byte value provided with the current 
// global 'crc8' value. 
// Returns current global crc8 value
//
unsigned char docrc8(unsigned char value)
{// See Application Note 27// TEST BUILDcrc8 = dscrc_table[crc8 ^ value];return crc8;
}//--------------------------------------------------------------------------
// TEST BUILD MAIN
//
void OWSearch_Func()
{short PortType=5,PortNum=1;int rslt,i,cnt;// TMEX API SETUP// get a session
//   session_handle = TMExtendedStartSession(PortNum,PortType,NULL);
//   if (session_handle <= 0)
//   {
//      printf("No session, %d\n",session_handle);
//      exit(0);
//   }// setup the port
//   rslt = TMSetup(session_handle);
//   if (rslt != 1)
//   {
//      printf("Fail setup, %d\n",rslt);
//      exit(0);
//   }// END TMEX API SETUP//搜索所有器件的示例// find ALL devicesprintf("\r\nFIND ALL\r\n");cnt = 0;rslt = OWFirst();while (rslt){// print device foundfor (i = 0; i < 8; ++i)printf("%02X", (short)ROM_NO[i]);printf("  %d\r\n",++cnt);rslt = OWNext();}
#if 0	//其他搜索示例// find only 0x1Aprintf("\r\nFIND ONLY 0x1A\r\n");cnt = 0;OWTargetSetup(0x1A);while (OWNext()){// check for incorrect typeif (ROM_NO[0] != 0x1A)break;// print device foundfor (i = 0; i < 8; ++i)printf("%02X", (short)ROM_NO[i]);printf("  %d\r\n",++cnt);}// find all but 0x04, 0x1A, 0x23, and 0x01printf("\r\nFIND ALL EXCEPT 0x10, 0x04, 0x0A, 0x1A, 0x23, 0x01\r\n");cnt = 0;rslt = OWFirst();while (rslt){// check for incorrect typeif ((ROM_NO[0] == 0x04) || (ROM_NO[0] == 0x1A) || (ROM_NO[0] == 0x01) || (ROM_NO[0] == 0x23) ||(ROM_NO[0] == 0x0A) || (ROM_NO[0] == 0x10))OWFamilySkipSetup();else{// print device foundfor (i = 0; i < 8; ++i)printf("%02X", (short)ROM_NO[i]);printf("  %d\r\n",++cnt);}rslt = OWNext();}
#endif// TMEX API CLEANUP// release the session
//   TMEndSession(session_handle);// END TMEX API CLEANUP
}

测试程序

void OWSearch_Func();void main(void)
{Timer_Init(TIMER_0, TIMER_MODE_2, GATE_DISABLE, CLK_Internal, 22118400, 10, STC_TIM_Priority_Highest);	//定时器配置为10us中断一次，8位重装载USART_Init(USART_MODE_1, Rx_ENABLE, STC_USART_Priority_Lowest, 22118400, 57600, DOUBLE_BAUD_DISABLE, USART_TIMER_1);while(1){		OWSearch_Func();delay_ms(1000);}	
}

实验现象

Proteus仿真

如图，成功正确搜索到各器件的ID

实机测试