DHT11 sensor error

oussy29 · December 31, 2021, 9:21pm

Hello, iam using this code..
when i compile it i got this error, any help please ?

#include <DHT.h>
#include <DHT_U.h>

//------------------Program Developed by R.GIRISH-------------------//
#include <LiquidCrystal.h>
#include <Servo.h>


#define DHT11 A0
const int ok = A1;
const int UP = A2;
const int DOWN = A3;
const int bulb = A4;
const int vap = A5;
const int rs = 12;
const int en = 11;
const int d4 = 5;
const int d5 = 4;
const int d6 = 3;
const int d7 = 2;
int ack = 0;
int pos = 0;
int sec = 0;
int Min = 0;
int hrs = 0;
int T_threshold = 25;
int H_threshold = 35;
int SET = 0;
int Direction = 0;
boolean T_condition = true;
boolean H_condition = true;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
Servo motor;
dht DHT;
void setup()
{
pinMode(ok, INPUT);
pinMode(UP, INPUT);
pinMode(DOWN, INPUT);
pinMode(bulb, OUTPUT);
pinMode(vap, OUTPUT);
digitalWrite(bulb, LOW);
digitalWrite(vap, LOW);
digitalWrite(ok, HIGH);
digitalWrite(UP, HIGH);
digitalWrite(DOWN, HIGH);
motor.attach(7);
motor.write(pos);
lcd.begin(16, 2);
Serial.begin(9600);
lcd.setCursor(5, 0);
lcd.print("Digital");
lcd.setCursor(4, 1);
lcd.print("Incubator");
delay(1500);
}
void loop()
{
if (SET == 0)
{
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Set Temperature:");
lcd.setCursor(0, 1);
lcd.print(T_threshold);
lcd.print(" *C");
while (T_condition)
{
if (digitalRead(UP) == LOW)
{
T_threshold = T_threshold + 1;
lcd.setCursor(0, 1);
lcd.print(T_threshold);
lcd.print(" *C");
delay(200);
}
if (digitalRead(DOWN) == LOW)
{
T_threshold = T_threshold - 1;
lcd.setCursor(0, 1);
lcd.print(T_threshold);
lcd.print(" *C");
delay(200);
}
if (digitalRead(ok) == LOW)
{
delay(200);
T_condition = false;
}
}
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Set Humidity:");
lcd.setCursor(0, 1);
lcd.print(H_threshold);
lcd.print("%");
delay(100);
while (H_condition)
{
if (digitalRead(UP) == LOW)
{
H_threshold = H_threshold + 1;
lcd.setCursor(0, 1);
lcd.print(H_threshold);
lcd.print("%");
delay(100);
}
if (digitalRead(DOWN) == LOW)
{
H_threshold = H_threshold - 1;
lcd.setCursor(0, 1);
lcd.print(H_threshold);
lcd.print("%");
delay(200);
}
if (digitalRead(ok) == LOW)
{
delay(100);
H_condition = false;
}
}
SET = 1;
}
ack = 0;
int chk = DHT.read11(DHT11);
switch (chk)
{
case DHTLIB_ERROR_CONNECT:
ack = 1;
break;
}
if (ack == 0)
{
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Temp:");
lcd.print(DHT.temperature);
lcd.setCursor(0, 1);
lcd.print("Humidity:");
lcd.print(DHT.humidity);
if (DHT.temperature >= T_threshold)
{
delay(3000);
if (DHT.temperature >= T_threshold)
{
digitalWrite(bulb, LOW);
}
}
if (DHT.humidity >= H_threshold)
{
delay(3000);
if (DHT.humidity >= H_threshold)
{
digitalWrite(vap, LOW);
}
}
if (DHT.temperature < T_threshold)
{
delay(3000);
if (DHT.temperature < T_threshold)
{
digitalWrite(bulb, HIGH);
}
}
if (DHT.humidity < H_threshold)
{
delay(3000);
if (DHT.humidity < H_threshold)
{
digitalWrite(vap, HIGH);
}
}
sec = sec + 1;
if (sec == 60)
{
sec = 0;
Min = Min + 1;
}
if (Min == 60)
{
Min = 0;
hrs = hrs + 1;
}
if (hrs == 8 && Min == 0 && sec == 0)
{
for (pos = 0; pos <= 180; pos += 1)
{
motor.write(pos);
delay(25);
}
}
if (hrs == 16 && Min == 0 && sec == 0)
{
hrs = 0;
for (pos = 180; pos >= 0; pos -= 1)
{
motor.write(pos);
delay(25);
}
}
}
if (ack == 1)
{
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("No Sensor data.");
lcd.setCursor(0, 1);
lcd.print("System Halted.");
digitalWrite(bulb, LOW);
digitalWrite(vap, LOW);
}
delay(1000);
}
//------------------Program Developed by R.GIRISH-------------------//

36:32:1: error: 'dht' does not name a type
dht DHT;
^~~
C:\Users\ousse\Documents\Arduino\36\36.ino: In function 'void loop()':
36:123:14: error: expected primary-expression before '.' token
int chk = DHT.read11(DHT11);
^
36:126:6: error: 'DHTLIB_ERROR_CONNECT' was not declared in this scope
case DHTLIB_ERROR_CONNECT:
^~~~~~~~~~~~~~~~~~~~
36:135:14: error: expected primary-expression before '.' token
lcd.print(DHT.temperature);
^
36:138:14: error: expected primary-expression before '.' token
lcd.print(DHT.humidity);
^
36:139:8: error: expected primary-expression before '.' token
if (DHT.temperature >= T_threshold)
^
36:142:8: error: expected primary-expression before '.' token
if (DHT.temperature >= T_threshold)
^
36:147:8: error: expected primary-expression before '.' token
if (DHT.humidity >= H_threshold)
^
36:150:8: error: expected primary-expression before '.' token
if (DHT.humidity >= H_threshold)
^
36:155:8: error: expected primary-expression before '.' token
if (DHT.temperature < T_threshold)
^
36:158:8: error: expected primary-expression before '.' token
if (DHT.temperature < T_threshold)
^
36:163:8: error: expected primary-expression before '.' token
if (DHT.humidity < H_threshold)
^
36:166:8: error: expected primary-expression before '.' token
if (DHT.humidity < H_threshold)
^
exit status 1
'dht' does not name a type

Burakimportant · December 31, 2021, 9:43pm

Greetings,

Change this to this

DHT dht;

After that change all DHT's into dht.

UKHeliBob · December 31, 2021, 9:52pm

And the constructor needs 2 parameters, the pin number and the DHT type. Have you looked at the DHT library examples ?

oussy29 · January 1, 2022, 11:30am

still having the same problem

oussy29 · January 1, 2022, 11:31am

#define DHT11 A0
DHT dht;

i just did it

UKHeliBob · January 1, 2022, 11:31am

Post your updated code with parameters in the constructor

oussy29 · January 1, 2022, 11:33am


#include <LiquidCrystal.h>
#include <Servo.h>
#include <DHT.h>
#include <DHT_U.h>

#define DHT11 A0
const int ok = A1;
const int UP = A2;
const int DOWN = A3;
const int bulb = A4;
const int vap = A5;
const int rs = 12;
const int en = 11;
const int d4 = 5;
const int d5 = 4;
const int d6 = 3;
const int d7 = 2;
int ack = 0;
int pos = 0;
int sec = 0;
int Min = 0;
int hrs = 0;
int T_threshold = 25;
int H_threshold = 35;
int SET = 0;
int Direction = 0;
boolean T_condition = true;
boolean H_condition = true;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
Servo motor;
DHT dht;
void setup()
{
pinMode(ok, INPUT);
pinMode(UP, INPUT);
pinMode(DOWN, INPUT);
pinMode(bulb, OUTPUT);
pinMode(vap, OUTPUT);
digitalWrite(bulb, LOW);
digitalWrite(vap, LOW);
digitalWrite(ok, HIGH);
digitalWrite(UP, HIGH);
digitalWrite(DOWN, HIGH);
motor.attach(7);
motor.write(pos);
lcd.begin(16, 2);
Serial.begin(9600);
lcd.setCursor(5, 0);
lcd.print("Digital");
lcd.setCursor(4, 1);
lcd.print("Incubator");
delay(1500);
}
void loop()
{
if (SET == 0)
{
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Set Temperature:");
lcd.setCursor(0, 1);
lcd.print(T_threshold);
lcd.print(" *C");
while (T_condition)
{
if (digitalRead(UP) == LOW)
{
T_threshold = T_threshold + 1;
lcd.setCursor(0, 1);
lcd.print(T_threshold);
lcd.print(" *C");
delay(200);
}
if (digitalRead(DOWN) == LOW)
{
T_threshold = T_threshold - 1;
lcd.setCursor(0, 1);
lcd.print(T_threshold);
lcd.print(" *C");
delay(200);
}
if (digitalRead(ok) == LOW)
{
delay(200);
T_condition = false;
}
}
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Set Humidity:");
lcd.setCursor(0, 1);
lcd.print(H_threshold);
lcd.print("%");
delay(100);
while (H_condition)
{
if (digitalRead(UP) == LOW)
{
H_threshold = H_threshold + 1;
lcd.setCursor(0, 1);
lcd.print(H_threshold);
lcd.print("%");
delay(100);
}
if (digitalRead(DOWN) == LOW)
{
H_threshold = H_threshold - 1;
lcd.setCursor(0, 1);
lcd.print(H_threshold);
lcd.print("%");
delay(200);
}
if (digitalRead(ok) == LOW)
{
delay(100);
H_condition = false;
}
}
SET = 1;
}
ack = 0;
int chk = DHT.read11(DHT11);
switch (chk)
{
case DHTLIB_ERROR_CONNECT:
ack = 1;
break;
}
if (ack == 0)
{
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Temp:");
lcd.print(dht.temperature);
lcd.setCursor(0, 1);
lcd.print("Humidity:");
lcd.print(dht.humidity);
if (dht.temperature >= T_threshold)
{
delay(3000);
if (dht.temperature >= T_threshold)
{
digitalWrite(bulb, LOW);
}
}
if (dht.humidity >= H_threshold)
{
delay(3000);
if (dht.humidity >= H_threshold)
{
digitalWrite(vap, LOW);
}
}
if (dht.temperature < T_threshold)
{
delay(3000);
if (dht.temperature < T_threshold)
{
digitalWrite(bulb, HIGH);
}
}
if (dht.humidity < H_threshold)
{
delay(3000);
if (dht.humidity < H_threshold)
{
digitalWrite(vap, HIGH);
}
}
sec = sec + 1;
if (sec == 60)
{
sec = 0;
Min = Min + 1;
}
if (Min == 60)
{
Min = 0;
hrs = hrs + 1;
}
if (hrs == 8 && Min == 0 && sec == 0)
{
for (pos = 0; pos <= 180; pos += 1)
{
motor.write(pos);
delay(25);
}
}
if (hrs == 16 && Min == 0 && sec == 0)
{
hrs = 0;
for (pos = 180; pos >= 0; pos -= 1)
{
motor.write(pos);
delay(25);
}
}
}
if (ack == 1)
{
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("No Sensor data.");
lcd.setCursor(0, 1);
lcd.print("System Halted.");
digitalWrite(bulb, LOW);
digitalWrite(vap, LOW);
}
delay(1000);
}

UKHeliBob · January 1, 2022, 11:35am

DHT dht;

Still no parameters in the constructor

oussy29 · January 1, 2022, 11:54am

#define DHTTYPE DHT11
DHT dht2 = DHT(A0,DHTTYPE);

is this correct ?

UKHeliBob · January 1, 2022, 12:46pm

No

It should be

#define DHTTYPE DHT11
DHT dht(A0, DHTTYPE);

You are declaring an object named dht which you use throughout the sketch when referring to the DHT11 sensor on pin A0

oussy29 · January 1, 2022, 12:53pm

now i got an other error in this expression

if (DHT.humidity < H_threshold)

Arduino : 1.8.16 (Windows 10), Carte : "Arduino Uno"

C:\Users\ousse\Documents\Arduino\36\36.ino: In function 'void loop()':

36:121:14: error: expected primary-expression before '.' token

int chk = DHT.read11(DHT11);

36:124:6: error: 'DHTLIB_ERROR_CONNECT' was not declared in this scope

case DHTLIB_ERROR_CONNECT:

  ^~~~~~~~~~~~~~~~~~~~

36:133:14: error: expected primary-expression before '.' token

lcd.print(DHT.temperature);

36:136:14: error: expected primary-expression before '.' token

lcd.print(DHT.humidity);

36:137:8: error: expected primary-expression before '.' token

if (DHT.temperature >= T_threshold)

36:140:8: error: expected primary-expression before '.' token

if (DHT.temperature >= T_threshold)

36:145:8: error: expected primary-expression before '.' token

if (DHT.humidity >= H_threshold)

36:148:8: error: expected primary-expression before '.' token

if (DHT.humidity >= H_threshold)

36:153:8: error: expected primary-expression before '.' token

if (DHT.temperature < T_threshold)

36:156:8: error: expected primary-expression before '.' token

if (DHT.temperature < T_threshold)

36:161:8: error: expected primary-expression before '.' token

if (DHT.humidity < H_threshold)

36:164:8: error: expected primary-expression before '.' token

if (DHT.humidity < H_threshold)

exit status 1

expected primary-expression before '.' token

Ce rapport pourrait être plus détaillé avec
l'option "Afficher les résultats détaillés de la compilation"
activée dans Fichier -> Préférences.

UKHeliBob · January 1, 2022, 1:32pm

Read what I wrote

You are trying to use an object named DHT rather than dht

Make the required changes and post the revised sketch if you still have problems

oussy29 · January 1, 2022, 1:39pm

Sorry, i still newbie
So i should replace all DHT with dht ?

UKHeliBob · January 1, 2022, 1:42pm

Basically yes, but not in the name of the library file (DHT.h) or in the constructor

I really would urge you to look at the examples that came with the library

oussy29 · January 1, 2022, 2:08pm

ok i will do this now

UKHeliBob · January 1, 2022, 2:13pm

Note particularly how the DHT object is declared, the parameters used and how the name of the DHT object is used in the code

rpiloverbd · January 1, 2022, 2:19pm

Hello, at first make sure that you've installed the dht.h library .

Since you're new, I think this tutorial will also help you to understand more.

oussy29 · January 4, 2022, 1:49pm

I even tryed the same code and library in this tutorial and i am still having the same problems, i 've read the full tutorial, but still didn't understand why i am getting these errors..
please guide me guys, i am tyring to have a correct code since i bought all composants and wire it togheter to build an automatic incubator..

UKHeliBob · January 4, 2022, 2:16pm

Are we supposed to understand the schematic of your project from that picture of a rats nest ?

I have seen some bad pictures of projects on the forum but this takes the biscuit

oussy29 · January 4, 2022, 2:42pm

my problem is with coding, i just made the circuit without any error
i just included this photo to show u that all is ready, only the code didn't work for me and i need help..

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