URGENT****ds18b20 thermal sensor

Hi,
I have a problem with DS18b20 sensor. I go through the coed "DS18B20 (Digital Temperature Sensor) and Arduino - Arduino Project Hub"
and it comply well, but in serial monitor it display the capacitance value! instead of temperature.

what is wrong?
thanks for your help

The capacitance value of what?

Post your code, and your schematic, if you want help.

Link in post#0 tries to go here: Arduino Project Hub

And it wants to connect to some hackster.io site (bad/ email spammer).
Leo..

When you say that the serial monitor displays a capacitance value, is that because the unit is 'F', which you have taken to stand for Farad?

Some backwards countries still measure temperature on the Farenheit scale, and not the derived SI unit of °C.

m_yousef:
Hi,
I have a problem with DS18b20 sensor. I go through the coed "DS18B20 (Digital Temperature Sensor) and Arduino - Arduino Project Hub"
and it comply well, but in serial monitor it display the capacitance value! instead of temperature.

what is wrong?
thanks for your help

What did the person that posted that project say when you asked them about the code outputing the readings in Farads ?

And why is your post 'Urgent' ?

m_yousef:
what is wrong?

Shouting URGENT is synonymous with 'demanding' us to jump to attention.
We are a volunteer community here.

Your link is bad.

.

The posted link works for me

The code shown is

// First we include the libraries
#include <OneWire.h> 
#include <DallasTemperature.h>
/********************************************************************/
// Data wire is plugged into pin 2 on the Arduino 
#define ONE_WIRE_BUS 2 
/********************************************************************/
// Setup a oneWire instance to communicate with any OneWire devices  
// (not just Maxim/Dallas temperature ICs) 
OneWire oneWire(ONE_WIRE_BUS); 
/********************************************************************/
// Pass our oneWire reference to Dallas Temperature. 
DallasTemperature sensors(&oneWire);
/********************************************************************/ 
void setup(void) 
{ 
 // start serial port 
 Serial.begin(9600); 
 Serial.println("Dallas Temperature IC Control Library Demo"); 
 // Start up the library 
 sensors.begin(); 
} 
void loop(void) 
{ 
 // call sensors.requestTemperatures() to issue a global temperature 
 // request to all devices on the bus 
/********************************************************************/
 Serial.print(" Requesting temperatures..."); 
 sensors.requestTemperatures(); // Send the command to get temperature readings 
 Serial.println("DONE"); 
/********************************************************************/
 Serial.print("Temperature is: "); 
 Serial.print(sensors.getTempCByIndex(0)); // Why "byIndex"?  
   // You can have more than one DS18B20 on the same bus.  
   // 0 refers to the first IC on the wire 
   delay(1000); 
}

The display should be in degrees C. What makes you think it is displaying a capacitance value?

 Serial.print("Temperature is: "); 
 Serial.print(sensors.getTempCByIndex(0));

I don't like to see "Urgent" in titles. It suggests that you think you should get help before other people who were already in the queue. That's not nice.

...R

cattledog:
The posted link works for me

Link in post#0 works now.

This sketch shows temp in Capacitance and Farad :slight_smile:
Connect the sensor output to D6, with a 4k7 pull up resistor.
Leo…

#include <DallasTemperature.h>
#include <OneWire.h>

OneWire oneWire(6); // pin D6
DallasTemperature sensors(&oneWire);
float tempC; // Celcius
float tempF; // Fahrenheit

void setup() {
  Serial.begin(115200);
  Serial.println("DS18B20 thermometer");
  sensors.begin();
}

void loop() {
  sensors.requestTemperatures();
  tempC = sensors.getTempCByIndex(0);
  tempF = tempC * 1.8 + 32.0; // Celcius to Fahrenheit
  Serial.print("The temperature is  ");
  Serial.print(tempC, 4);
  Serial.print(" Celcius  ");
  Serial.print(tempF, 1); // one decimal place
  Serial.println(" Fahrenheit");
}