首先
寫一個獲取DS18B20的64位序列號的keil工程,獲取需要連接的DS18B20器件的序列號。
uint8_t rom[8];
void read_rom(void)
{
uint8_t index;
ds18b20_init();
ds18b20_write_byte(0x33);
for (index = 0;index < 8;index++)
{
rom[index] = ds18b20_read_byte();
}
}
之后在將獲取到的DS18B20器件的序列號通過數組保存起來,再新建一個獲取多點溫度的keil工程,發送匹配64位序列號,獲取溫度即可。
詳細內容見單片機源程序:
- uint8_t rom1[8]={0x28,0x0B,0xAC,0x79,0x97,0x16,0x03,0x39};
- uint8_t rom2[8]={0x28,0xF2,0x80,0x79,0x97,0x15,0x03,0x51};
- uint8_t rom3[8]={0x28,0xFF,0x64,0x79,0x97,0x16,0x03,0x8B};
- uint8_t rom4[8]={0x28,0x6F,0x31,0x79,0x97,0x15,0x03,0x28};
- uint8_t rom5[8]={0x28,0x1C,0x5C,0x79,0x97,0x15,0x03,0x14};
- uint8_t rom6[8]={0x28,0xED,0xD8,0x79,0x97,0x16,0x03,0xD0};
- uint8_t rom7[8]={0x28,0x94,0xB0,0x79,0x97,0x15,0x03,0xA4};
- uint8_t rom8[8]={0x28,0xAE,0xD5,0x79,0x97,0x16,0x03,0x10};
- uint8_t rom9[8]={0x28,0xC0,0xC2,0x79,0x97,0x16,0x03,0xED};
- void DS18B20_Matrom(unsigned char a)
- {
- unsigned char j; //用于循環
- ds18b20_init();
- ds18b20_write_byte(0x55); //發送匹配ROM命令
- if(a==1)
- {
- for(j=0;j<8;j++)
- {
- ds18b20_write_byte(rom1[j]);//發送18B20的序列號,先發送低字節
- }
- }
- if(a==2)
- {
- for(j=0;j<8;j++)
- {
- ds18b20_write_byte(rom2[j]);//發送18B20的序列號,先發送低字節
- }
- }
- if(a==3)
- {
- for(j=0;j<8;j++)
- {
- ds18b20_write_byte(rom3[j]);//發送18B20的序列號,先發送低字節
- }
- }
- if(a==4)
- {
- for(j=0;j<8;j++)
- {
- ds18b20_write_byte(rom4[j]);//發送18B20的序列號,先發送低字節
- }
- }
- if(a==5)
- {
- for(j=0;j<8;j++)
- {
- ds18b20_write_byte(rom5[j]);//發送18B20的序列號,先發送低字節
- }
- }
- if(a==6)
- {
- for(j=0;j<8;j++)
- {
- ds18b20_write_byte(rom6[j]);//發送18B20的序列號,先發送低字節
- }
- }
- if(a==7)
- {
- for(j=0;j<8;j++)
- {
- ds18b20_write_byte(rom7[j]);//發送18B20的序列號,先發送低字節
- }
- }
- if(a==8)
- {
- for(j=0;j<8;j++)
- {
- ds18b20_write_byte(rom8[j]);//發送18B20的序列號,先發送低字節
- }
- }
- if(a==9)
- {
- for(j=0;j<8;j++)
- {
- ds18b20_write_byte(rom9[j]);//發送18B20的序列號,先發送低字節
- }
- }
- }
- int16_t read_temp(uint8_t rom) //啟動溫度轉換,讀取溫度
- {
- u8 tl=0,th=0;
- if(ds18b20_init())
- return 0x7fff;
- ds18b20_write_byte(0xCC);
- ds18b20_write_byte(0x44);//啟動DS18B20進行溫度轉換
- DS18B20_Matrom(rom);//匹配RAM,適用多個點的情況
-
- ds18b20_write_byte(0xBE);//讀DS18B20內部RAM中9字節的溫度數據
- tl=ds18b20_read_byte();//讀低8位
- th=ds18b20_read_byte();//讀高8位
- return (th<<8)+tl;
- }
- float get_ntemp(uint8_t rom)
- {
- float temp=0;
- temp = read_temp(rom);
- temp = temp*0.0625;
-
- return temp;
- }
復制代碼
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