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Topic: exit status 'dht' does not name a type (Read 745 times) previous topic - next topic

avvy66

This is the code for a temperature and humidity sensor, and I have the Arduino main DHT master library, but it is not being used, even when I include that library.

Code: [Select]
#include <DHT.h>


    /*  DHT11/ DHT22 Sensor Temperature and Humidity Tutorial
     *  Program made by Dejan Nedelkovski,
     *  www.HowToMechatronics.com
     */
    /*
     * You can find the DHT Library from Arduino official website
     * https://playground.arduino.cc/Main/DHTLib
     */
    #include <LiquidCrystal.h> // includes the LiquidCrystal Library
    #include <dht.h>
    #define dataPin 2
    LiquidCrystal lcd(1, 2, 4, 5, 6, 7); // Creates an LCD object. Parameters: (rs, enable, d4, d5, d6, d7)
    dht DHT;
    void setup() {
      lcd.begin(16,2); // Initializes the interface to the LCD screen, and specifies the dimensions (width and height) of the display
    }
    void loop() {
      int readData = DHT.read22(dataPin);
      float t = DHT.temperature;
      float h = DHT.humidity;
      lcd.setCursor(0,0); // Sets the location at which subsequent text written to the LCD will be displayed
      lcd.print("Temp.: "); // Prints string "Temp." on the LCD
      lcd.print(t); // Prints the temperature value from the sensor
      lcd.print(" C");
      lcd.setCursor(0,1);
      lcd.print("Humi.: ");
      lcd.print(h);
      lcd.print(" %");
      delay(2000);
    }


Temp_Humid.ino:20: error: 'dht' does not name a type
     dht DHT;
     ^
/home/rob/Arduino/Temp_Humid.ino/Temp_Humid.ino/Temp_Humid.ino.ino: In function 'void loop()':
Temp_Humid.ino:25: error: expected primary-expression before '.' token
       int readData = DHT.read22(dataPin);
                         ^
Temp_Humid.ino:26: error: expected primary-expression before '.' token
       float t = DHT.temperature;
                    ^
Temp_Humid.ino:27: error: expected primary-expression before '.' token
       float h = DHT.humidity;
                    ^
Multiple libraries were found for "DHT.h"
 Used: /home/rob/Arduino/libraries/DHT
 Not used: /home/rob/Arduino/libraries/arduino-DHT-master
 Not used: /home/rob/Arduino/libraries/DHT_sensor_library
 Not used: /home/rob/Downloads/arduino-1.8.5/libraries/arduino-DHT-master
 Not used: /home/rob/Downloads/arduino-1.8.5/libraries/DHT-sensor-library-master
Multiple libraries were found for "LiquidCrystal.h"
 Used: /home/rob/Arduino/libraries/LiquidCrystal
 Not used: /home/rob/Arduino/libraries/Newliquidcrystal_1.3.5
 Not used: /home/rob/Downloads/arduino-1.8.5/libraries/Newliquidcrystal_1.3.5
 Not used: /home/rob/Downloads/arduino-1.8.5/libraries/LiquidCrystal
Using library DHT in folder: /home/rob/Arduino/libraries/DHT (legacy)
Using library LiquidCrystal in folder: /home/rob/Arduino/libraries/LiquidCrystal (legacy)
exit status 1
'dht' does not name a type

ieee488

What procedure did you follow to include the DHT library?

avvy66

#2
Jun 13, 2018, 10:06 am Last Edit: Jun 13, 2018, 05:06 pm by avvy66
What procedure did you follow to include the DHT library?
I downloaded the Arduino DHT master library, then extracted it into the Arduino-1.8.5 library directory.

By your question, I guess that I have not done it correctly!

ieee488

By your question, I guess that I have not done it correctly!
You are correct.  :-)



.

avvy66

So how should I install downloaded libraries to the Arduino IDE library directory.

avvy66

When I googled how to install downloaded library files to Arduino, there were many links just saying they could be manually added or added from a zip.

Ok so what have I done wrong if that is the case.

ieee488

Which library?


Properly written libraries can be added from the IDE.
If not, add it manually.


.

avvy66

#7
Jun 15, 2018, 09:32 pm Last Edit: Jun 15, 2018, 09:34 pm by avvy66
Which library?


Properly written libraries can be added from the IDE.
If not, add it manually.


.
The libarary was the arduino-DHT-master, and I just extracted it from a zip file into the arduino library. But you said that I did not install it properly or the correct way, so which is the correct way.

It still leaves me with the original problem of dht does not name a type

ieee488

#8
Jun 16, 2018, 12:19 am Last Edit: Jun 16, 2018, 12:29 am by ieee488
The libarary was the arduino-DHT-master, and I just extracted it from a zip file into the arduino library. But you said that I did not install it properly or the correct way, so which is the correct way.

It still leaves me with the original problem of dht does not name a type
Edit: where did  #include <DHT.h> in first line come from ?

None of the examples for that library has it!

avvy66

Edit: where did  #include <DHT.h> in first line come from ?

None of the examples for that library has it!
I must have included it from the list in the library menu.

I 'm not using examples as the code is froma  youtube video on using a DHT22 with the arduino to measure temperature and humidity.

I have 3 DHT libraries: arduino_DHT-master, DHT and DHT-sensor-library-master.

So what do I do to get rid of the error message.
Thanks

ieee488

I must have included it from the list in the library menu.

I 'm not using examples as the code is froma  youtube video on using a DHT22 with the arduino to measure temperature and humidity.

I have 3 DHT libraries: arduino_DHT-master, DHT and DHT-sensor-library-master.

So what do I do to get rid of the error message.
Thanks
Why do you need 3 DHT libraries?



avvy66

As I use linux, I found on Adafruits website that the library folder for Ardiuno is under the sketchbook folder. so I have copied the relevant libraries to the sketchbook/library folder.

I still get the same error

ieee488

As I use linux, I found on Adafruits website that the library folder for Ardiuno is under the sketchbook folder. so I have copied the relevant libraries to the sketchbook/library folder.

I still get the same error
I was able to compile your sketch just fine after fixing the error.

I am on Linux Mint 18.

avvy66

#13
Jun 16, 2018, 11:37 pm Last Edit: Jun 17, 2018, 08:55 am by avvy66
I was able to compile your sketch just fine after fixing the error.

I am on Linux Mint 18.
On your question as to why I need 3 libraries is because each of the different temp plus humidity projects on youtube either say or include a link to the DHT library they have used for their project.

Well what was the error ? Please tell.

I am using Linux Ubuntu 18.04

ieee488

Use the original example sketch.

Do not make changes unless you know what you are doing which you clearly don't.


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