一個簡單的onewire(單總線)溫度測試小程序

ID:406093 · 發表于 2018-10-30 17:13

onewire(單總線)是DALLAS公司推出的外圍串行擴展總線，傳輸時鐘信號又傳輸數據，而且能夠進行雙向通信，具有節省I/O口線、資源結構簡單、成本低廉、便于總線擴展和維護等諸多優點。常用到單總線的器件，一般是穩定傳感器，如DS18B20、DS2431。

以下是一個簡單的onewire(單總線)溫度測試程序，希望大家能夠喜歡。

// LCD module connections
sbit LCD_RS at P2_0_bit;
sbit LCD_EN at P2_1_bit;
sbit LCD_D4 at P2_2_bit;
sbit LCD_D5 at P2_3_bit;
sbit LCD_D6 at P2_4_bit;
sbit LCD_D7 at P2_5_bit;
// End LCD module connections
// OneWire pinout
sbit OW_Bit at P1_2_bit;
// end OneWire definition
// Set TEMP_RESOLUTION to the corresponding resolution of used DS18x20 sensor:
// 18S20: 9 (default setting; can be 9,10,11,or 12)
// 18B20: 12
const unsigned short TEMP_RESOLUTION = 9;
char *text = "000.0000";
unsigned temp;
void Display_Temperature(unsigned int temp2write) {
const unsigned short RES_SHIFT = TEMP_RESOLUTION - 8;
char temp_whole;
unsigned int temp_fraction;
// check if temperature is negative
if (temp2write & 0x8000) {
text[0] = '-';
temp2write = ~temp2write + 1;
}
// extract temp_whole
temp_whole = temp2write >> RES_SHIFT;
// convert temp_whole to characters
if (temp_whole/100)
text[0] = temp_whole/100 + 48;
else
text[0] = '0';
text[1] = (temp_whole/10)%10 + 48; // Extract tens digit
text[2] = temp_whole%10 + 48; // Extract ones digit
// extract temp_fraction and convert it to unsigned int
temp_fraction = temp2write << (4-RES_SHIFT);
temp_fraction &= 0x000F;
temp_fraction *= 625;
// convert temp_fraction to characters
text[4] = temp_fraction/1000 + 48; // Extract thousands digit
text[5] = (temp_fraction/100)%10 + 48; // Extract hundreds digit
text[6] = (temp_fraction/10)%10 + 48; // Extract tens digit
text[7] = temp_fraction%10 + 48; // Extract ones digit
// print temperature on LCD
Lcd_Out(2, 5, text);
}
void main() {
Lcd_Init(); // Initialize LCD
Lcd_Cmd(_LCD_CLEAR); // Clear LCD
Lcd_Cmd(_LCD_CURSOR_OFF); // Turn cursor off
Lcd_Out(1, 1, " Temperature: ");
// Print degree character, 'C' for Centigrades
Lcd_Chr(2,13,223); // different LCD displays have different char code for degree
// if you see greek alpha letter try typing 178 instead of 223
Lcd_Chr(2,14,'C');
//--- main loop
do {
//--- perform temperature reading
Ow_Reset(); // Onewire reset signal
Ow_Write(0xCC); // Issue command SKIP_ROM
Ow_Write(0x44); // Issue command CONVERT_T
Delay_us(120);
Ow_Reset();
Ow_Write(0xCC); // Issue command SKIP_ROM
Ow_Write(0xBE); // Issue command READ_SCRATCHPAD
temp = Ow_Read();
temp = (Ow_Read() << 8) + temp;
//--- Format and display result on Lcd
Display_Temperature(temp);
Delay_ms(500);
} while (1);
}

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相關信息：http://www.zg4o1577.cn/bbs/dpj-136722-1.html

ID:258566 · 發表于 2018-10-30 17:33

帶庫的編譯器mikroe

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一個簡單的onewire(單總線)溫度測試小程序

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