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@AlexLPD
Last active March 13, 2018 17:19
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thermistor_read_ABC_coeficients
//This is an example code on how to read a thermistor, the "Thermimistor.h" Lib out there only acepts Beta
//coeficient and in my case yield to incorrects results, this a way more accurrate way to read the
//thermistor, in case you have odd or wrong meassurements please follow this steps:
//
//For get the acurrate results for this code you will need;
//a multymeter, a NTC thermistor, another accurrate themperature
//probe meter.
//Step 1.- Set multimiter on resistance meassurement mode
//Step 2.- Read and anotate the actual resistance of the thermistor
//and the actual temperature (allow 1min to get stable meassurement).
//Some Hot water and a cup.
//Step 3.- place both sensors (Thermistor and temperature probe in a
//recipient containing water at ambient temperature).
//In another cup heat up some water.
//Add hot water until you heat more than 10°C the temp probe, wait for
//stable meassurement and anotate the temperature and the resistance.
//Add more water to heat up the element 20° from the first meassurement.
//Take note of the temperature and resistance.
//Step 4.-
//Go to the website:
//http://www.thinksrs.com/downloads/programs/Therm%20Calc/NTCCalibrator/NTCcalculator.htm
//and set your data on it.
//The calculator will deliver three values we need on the code: A, B and C.
//Step 5.-
//Replace the values you get in the calculator on this code.
//Step 6.- Upload and test it.
//Place both sensors on ambient water, warm water and hot water, use the temperature
//probe to chek for accurracy.
//Original code from: https://www.youtube.com/watch?v=-_XkGju35MI
//Procedure: Alex Santiago - 12/03/2018
//Tested on a 10K NTC B3450 -12/03/2018
//Arduino Mega at 5Vcc.
*/
int ThermistorPin = A1;
int Vo;
float R1 = 10000;
float logR2, R2, T, Tc, Tf;
float c1 = 1.290256288e-03; //coeficient A
float c2 = 1.901591170e-04; //coeficient B
float c3 = 3.997482735e-07; //coeficient C
void setup() {
Serial.begin(9600);
}
void loop() {
Vo = analogRead(ThermistorPin);
R2 = R1 * (1023.0 / (float)Vo - 1.0);
logR2 = log(R2);
T = (1.0 / (c1 + c2*logR2 + c3*logR2*logR2*logR2));
Tc = T - 273.15;
Tf = (Tc * 9.0)/ 5.0 + 32.0;
Serial.print("Temperature: ");
Serial.print(Tc);
Serial.println(" C");
delay(500);
}
//
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