温度修正的电导率数据采集和存储

王大富

1. #include "Arduino.h"
   
2. #include <OneWire.h>
   
3. #include <SD.h>//SD卡模块
   
4. #include <SPI.h>
   
5. #include <OneWire.h>
   
6. File myFile;
   
7. 
   
8. #define EC_PIN A0
   
9. float voltage, ecValue, temperature = 25.0;
   
10. float _kvalueLow = 1, _kvalueHigh = 1, _kvalue = 1, rawEC, valueTemp, value;
    
11. char teststring;                                    
    
12. 
    
13. OneWire  ds(2);  // 连接arduino2引脚
    
14. float celsius, fahrenheit;
    
15. float Temp_Buffer = 0;
    
16. 
    
17. void setup()
    
18. {
    
19.   pinMode(A0, INPUT);
    
20.   Serial.begin(115200);
    
21.   if (SD.begin())
    
22.   {Serial.println("SD card is ready to use");
    
23.   }else
    
24.   {Serial.println("SD card aaaazinutialization failed");
    
25.    return;
    
26.     }
    
27. //SD.remove("example.txt");  //删除文件example.txt         
    
28. }
    
29. 
    
30. 
    
31. void loop()
    
32. {
    
33.    
    
34.     while(Serial.available()){
    
35.     teststring = strcat(Serial.read(),".txt") ;
    
36.     Serial.print(teststring);
    
37.     myFile=SD.open("123.txt",FILE_WRITE);}
    
38.    
    
39. //   myFile=SD.open("test.txt",FILE_WRITE);//创建并打开文件进行写入
    
40. //   myFile.print("ecValue=");
    
41. //   myFile.println(ecValue);
    
42. //   myFile.close();
    
43.    
    
44.   Temp_Buffer = readDs18b20();
    
45.   
    
46.   //digitalWrite(5, HIGH);
    
47.   digitalWrite(5, LOW);
    
48.   _kvalue = 1;
    
49.   static unsigned long timepoint = millis();
    
50.   if (millis() - timepoint > 1000U)
    
51.   { timepoint = millis();
    
52.     //Serial.print("A0="); Serial.print(analogRead(EC_PIN));
    
53.     voltage = analogRead(EC_PIN) / 1024.0 * 5000;//电压毫伏
    
54.    // Serial.print(" voltage="); Serial.print(voltage);
    
55.     rawEC = 1000 * voltage / 820.0 / 200.0;//原始电导率，电压与电导率的线性比列关系，有先前实验得到
    
56.     //Serial.print(" rawEC="); Serial.print(rawEC);
    
57.     value = rawEC * _kvalue;//初始不计算仪器引起的误差
    
58.     if (valueTemp > 2.5) {
    
59.       _kvalue = _kvalueHigh;//高校正值
    
60.     }
    
61.     else if (valueTemp < 2.0) {
    
62.       _kvalue = _kvalueLow;//低校正值
    
63.     }
    
64.    value = rawEC * _kvalue;//校正机械误差后的电导率，_kvalueLow和_kvalueHigh由实际的电导率比上测试得到的电导率
    
65.    temperature =celsius; //dht.getTemperature();//校正后的电导率
    
66.    ecValue = value / (1.0 + 0.0185 * (temperature - 25.0));//修正后的电导率，修正完以后都是25摄氏度下的数据，因此用除
    
67.    //Serial.print(" temperature:");Serial.print(temperature, 1);Serial.print("^C  EC:");
    
68.    Serial.print(ecValue);Serial.println("ms/cm");
    
69.      
    
70.   }
    
71. }
    
72. 
    
73. 
    
74. float readDs18b20()
    
75. {
    
76.   byte i;
    
77.   byte present = 0;
    
78.   byte type_s;
    
79.   byte data[12];
    
80.   byte addr[8];
    
81. 
    
82.    
    
83.   if ( !ds.search(addr)) {
    
84.     // Serial.println("No more addresses.");
    
85.     // Serial.println();
    
86.     ds.reset_search();
    
87.     // return 0;
    
88.   }
    
89.   
    
90.    //Serial.print("ROM =");
    
91.   for( i = 0; i < 8; i++) {
    
92.     //Serial.write(' ');
    
93.     //Serial.print(addr[i], HEX);
    
94.   }
    
95. 
    
96.   if (OneWire::crc8(addr, 7) != addr[7]) {
    
97.      // Serial.println("CRC is not valid!");
    
98.       return 0;
    
99.   }
    
100.   //Serial.println();
     
101.   
     
102.   // the first ROM byte indicates which chip
     
103.   switch (addr[0]) {
     
104.     case 0x10:
     
105.       //Serial.println("  Chip = DS18S20");  // or old DS1820
     
106.       type_s = 1;
     
107.       break;
     
108.     case 0x28:
     
109.       //Serial.println("  Chip = DS18B20");
     
110.       type_s = 0;
     
111.       break;
     
112.     case 0x22:
     
113.      // Serial.println("  Chip = DS1822");
     
114.       type_s = 0;
     
115.       break;
     
116.     default:
     
117.      // Serial.println("Device is not a DS18x20 family device.");
     
118.       return 0;
     
119.   }
     
120. 
     
121.   ds.reset();
     
122.   ds.select(addr);
     
123.   ds.write(0x44,1);         // start conversion, with parasite power on at the end
     
124.    
     
125.   delay(1000);     // maybe 750ms is enough, maybe not
     
126.   // we might do a ds.depower() here, but the reset will take care of it.
     
127.    
     
128.   present = ds.reset();
     
129.   ds.select(addr);   
     
130.   ds.write(0xBE);         // Read Scratchpad
     
131. 
     
132.   //Serial.print("  Data = ");
     
133.   //Serial.print(present,HEX);
     
134.   //Serial.print(" ");
     
135.   for ( i = 0; i < 9; i++) {           // we need 9 bytes
     
136.     data[i] = ds.read();
     
137.    // Serial.print(data[i], HEX);
     
138.   //  Serial.print(" ");
     
139.   }
     
140. // Serial.print(" CRC=");
     
141. // Serial.print(OneWire::crc8(data, 8), HEX);
     
142. // Serial.println();
     
143. 
     
144.   // convert the data to actual temperature
     
145. 
     
146.   unsigned int raw = (data[1] << 8) | data[0];
     
147.   if (type_s) {
     
148.     raw = raw << 3; // 9 bit resolution default
     
149.     if (data[7] == 0x10) {
     
150.       // count remain gives full 12 bit resolution
     
151.       raw = (raw & 0xFFF0) + 12 - data[6];
     
152.     }
     
153.   } else {
     
154.     byte cfg = (data[4] & 0x60);
     
155.     if (cfg == 0x00) raw = raw << 3;  // 9 bit resolution, 93.75 ms
     
156.     else if (cfg == 0x20) raw = raw << 2; // 10 bit res, 187.5 ms
     
157.     else if (cfg == 0x40) raw = raw << 1; // 11 bit res, 375 ms
     
158.     // default is 12 bit resolution, 750 ms conversion time
     
159.   }
     
160.   celsius = (float)raw / 16.0;
     
161.   //Serial.print("  Temperature = ");
     
162.   //Serial.print(celsius);
     
163.   //Serial.print(" Celsius, ");   
     
164.   return celsius;
     
165. }
     
166. 
     
167. 
     
168. 
     
169. 
     
170. 
     
171. 
     
172. 
     
173. 
     
174. //用于计算机械误差
     
175. //    if()
     
176. //    {if (rawEC>0.9 && rawEC<1.9)
     
177. //      {compECsolution = 1.413*(1.0+0.0185*(temperature-25.0));//通过温度校正后的到的真实值
     
178. //      kvalueLow = compECsolution/(1000.0*voltage/820.0/200.0);//机械校正系数为已知校正溶液的电导率比上实际测试得到的电导率   
     
179. //      round(kvalueLow,2);}
     
180. //    else if (rawEC>9 && rawEC<16.8)
     
181. //      {compECsolution = 12.88*(1.0+0.0185*(temperature-25.0));
     
182. //      kvalueHigh = compECsolution//(1000.0*voltage/820.0/200.0);//反过来如果已知了测试值想要得到真实值则应该乘以机械修正系数
     
183. //      round(kvalueHigh,2);}
     
184. //     }

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