Nominal value of thermistor

I have attached an arduino nano and add a thermistor device with a branch of resistors( 47k and 18k) . It gives an erroneous and fixed value because it is connected to a branch of resistors. What nominal value must have the thermistor and what should be the value of the other resistor. This is not specified !!!
Thank you

Oops, sorry had the wrong tab open :slight_smile:

HI @manrobles,

You are having trouble adding a thermistor right? What is the issue you are having with adding the thermistor to your dashboard? Would be helpful to share code and also wiring.

-B

Hi.
Thanks for answering.
I had not entered the code to arduino, that’s why the sensor did not work !!!
Already did . At this moment I have a fixed 4,7K branch (thermistor) and 12k to earth. I have 34 degrees celcuis. The temperature does not change since 4k7 is fixed. Somewhere in the code, you should be able to set the nominal value of the thermistor. BUT I DO NOT FIND IT !!!.
I enclose a copy of my code !!
Also the arduino with ENC28JC is hung very often. This module is fed with 3.5 v of independent source since it consumes a lot of current. But just as it falls !!!
You know why ???
Thanks for your answer !!!

Sincerely
Pedro

#define CAYENNE_PRINT Serial
#include <UIPEthernet.h>
#include <BlynkSimpleUIPEthernet.h>
#include <CayenneDefines.h>
#include <CayenneEthernetClient.h>
char token = “************”;
#include <CayenneTemperature.h>
#define VIRTUAL_PIN V1
const int thermistorPin = 3;
const float resistance = 12000;
Thermistor thermistor(thermistorPin, resistance);
void setup()
{
Serial.begin(9600);
Cayenne.begin(token);
}
void loop()
{
Cayenne.run();
}
CAYENNE_OUT(VIRTUAL_PIN)
{
Cayenne.celsiusWrite(VIRTUAL_PIN, thermistor.getCelsius());
}

Hello
Good night
I need to measure temperarura with arduino and I have created a widget.
Looking at the book Cayenne temperature I see that the Steinhart-Hart formula is used.
But it seems to me that the values ​​of the constants A, B, C are a particular thermistor. Please, I need to know which specific thermistor model is used for the library.
Thank you

Hi @manrobles,

You should be able to set the resistance in the code. Are you using the sketch file that we have provided for thermistors?

You can look at it here: https://github.com/myDevicesIoT/CayenneArduinoSamples/blob/master/Sensors/Thermistor/Thermistor.ino

See image below as well.

I hope this helps!

-B

@manrobles,

I did some investigation in another thread…

Cheers,

Craig