thermometer diode based

1/*
2
3  Thermometer based on 1n4148 silicon diode used as temperature  sensor.The thermometer is based on the diode characteristic that the increase of  the temperature its forward voltage (VF) is lowered by 2,2mV / ° C.
4Fixing the  value of Vf = VF0 at ambient temperature t0, the temperature value
5t is calculated  with the following formula:
6
7t= t0 - [vf(t)- vf0]* K
8
9with K = 1 / 2,2mV
10
11The  value of Vf (t) = dtemp -vf0 is obtained by averaging values of 1024 by acquiring  as many vf values
12
13The result of t is shown on the serial monitor
14*/
15
16
17//  set pin numbers:
18
19const int in = A0;          // used to bias the diode  anode
20const  int t0 = 20.3;
21const float vf0 = 573.44;
22// variables will change:
23
24int  i;
25float dtemp, dtemp_avg, t;
26
27void setup() {
28  Serial.begin(9600);
29  pinMode(in, INPUT_PULLUP);            // set the  pin IN with npull up to bias  the diode
30
31}
32
33void loop() {
34  dtemp_avg = 0;
35  for (i = 0; i <  1024; i++) {
36    float vf = analogRead(A0) * (4976.30 / 1023.000);
37    //Serial.println(vf);
38    dtemp = (vf - vf0) * 0.4545454;
39    dtemp_avg = dtemp_avg + dtemp;
40  }
41  t = t0 - dtemp_avg / 1024;
42  Serial.print("temperature in Celcius degree)   = " );
43  Serial.println(t);
44  
45  delay (1000);
46
47}

1/*
2
3  Thermometer based on 1n4148 silicon diode used as temperature
4  sensor.The thermometer is based on the diode characteristic that the increase of
5  the temperature its forward voltage (VF) is lowered by 2,2mV / ° C.
6Fixing the
7  value of Vf = VF0 at ambient temperature t0, the temperature value
8t is calculated
9  with the following formula:
10
11t= t0 - [vf(t)- vf0]* K
12
13with K = 1 / 2,2mV
14
15The
16  value of Vf (t) = dtemp -vf0 is obtained by averaging values of 1024 by acquiring
17  as many vf values
18
19The result of t is shown on the serial monitor
20*/
21
22
23//
24  set pin numbers:
25
26const int in = A0;          // used to bias the diode  anode
27const
28  int t0 = 20.3;
29const float vf0 = 573.44;
30// variables will change:
31
32int
33  i;
34float dtemp, dtemp_avg, t;
35
36void setup() {
37  Serial.begin(9600);
38
39  pinMode(in, INPUT_PULLUP);            // set the  pin IN with npull up to bias
40  the diode
41
42}
43
44void loop() {
45  dtemp_avg = 0;
46  for (i = 0; i <
47  1024; i++) {
48    float vf = analogRead(A0) * (4976.30 / 1023.000);
49    //Serial.println(vf);
50
51    dtemp = (vf - vf0) * 0.4545454;
52    dtemp_avg = dtemp_avg + dtemp;
53  }
54
55  t = t0 - dtemp_avg / 1024;
56  Serial.print("temperature in Celcius degree)
57   = " );
58  Serial.println(t);
59  
60  delay (1000);
61
62}