Quote
This sketch prints temperature and humidity in serial monitor OK.
 Quote  from AWOL I very, very much doubt that.

 You have done nothing to help. Now you call me a liar.I have rewritten the code using  others input and thought to repost a fresh sketch and not to make the other post 10 pages. personally I don't think you know how to write crap if you can't figure what I am trying to do. Maybe you should put the bottle up!

This sketch prints temperature and humidity in serial monitor OK. I am not sure if I am using the right code to read the outputs of temp/humidity to  turn on and off the LED’s. If the temperature falls below 60 degrees turn on ledpin8 and if above 80 degrees turn of ledpin8. Right now my room temp is 77 degrees, when I run the program ledpin8 goes high then low in one click it does not stay high till 80 degrees. Humidity(ledpin9) just goes high then low in less than a second. I just want to turn on ledpin8 when the temperature is below 60 degrees and turn off ledpin8 when the temperature  reaches 80 degrees.This is only my second sketch...noobie
Thanks





#include <dht11.h>

dht11 DHT11;

void setup()
{const int LEDPIN8 = 8;       // Temp
  const int LEDPIN9 = 9;       // Humidity
 pinMode (LEDPIN8, OUTPUT); // Temp
 pinMode (LEDPIN9, OUTPUT); // Humidity
 
const int THRESHOLD1 = 60;   // Temp lower limit turn on
const int THRESHOLD3 = 80;   // Temp upper limit turn off
const int THRESHOLD2 = 50;  // humidity lower limit turn on
const int THRESHOLD4 = 75;   // humidity upper limit turn off
float Temperature;
float Humidity;

  DHT11.attach(2);
  Serial.begin(9600);
 
 
}

void loop()
{  const int LEDPIN8 = 8;       // Temp
  const int LEDPIN9 = 9;       // Humidity
 pinMode (LEDPIN8, OUTPUT); // Temp
 pinMode (LEDPIN9, OUTPUT); // Humidity
 
const int THRESHOLD1 = 60;   // Temp lower limit turn on
const int THRESHOLD3 = 80;   // Temp upper limit turn off
const int THRESHOLD2 = 50;  // humidity lower limit turn on
const int THRESHOLD4 = 75;   // humidity upper limit turn off
float Temperature;
float Humidity;


  Serial.println("\n");

  int chk = DHT11.read();

  Serial.print("Read sensor: ");
  switch (chk)
  {
  case 0:
    Serial.println("OK");
    break;
  case -1:
    Serial.println("Checksum error");
    break;
  case -2:
    Serial.println("Time out error");
    break;
  default:
    Serial.println("Unknown error");
    break;
  }

  Serial.print("Humidity (%): ");
  Serial.println((float)DHT11.humidity, DEC);

 
  Serial.print("Temperature (F): ");
  Serial.println(DHT11.fahrenheit(), DEC);
 
 
 
 
  //Temperature
 
  Temperature = (DHT11.fahrenheit(), DEC);
 
   if (DHT11.fahrenheit(), DEC < THRESHOLD1)           // temp turn on led...less than 60 degrees
    digitalWrite(LEDPIN8, HIGH);
   
   
    if (DHT11.fahrenheit(), DEC > THRESHOLD3)           // temp turn off led.. more than 80 degrees
   
    digitalWrite(LEDPIN8,LOW);
   
   
    //Humidity
   
    Humidity = (DHT11.humidity, DEC);
   
     if (DHT11.humidity, DEC < THRESHOLD2)           // Humidity turn on led than 50 percent
    digitalWrite(LEDPIN9, HIGH);
   

  if (DHT11.humidity, DEC > THRESHOLD4)           // Humidity turn off led.. more than 75 percent
   
    digitalWrite(LEDPIN9,LOW);


 

 
  delay(200);
}

What do you expect this
Code:

if (DHT11.fahrenheit(), DEC < THRESHOLD1) 

to do? If the temp is lower than 60 turn on Ledpin6
Looks like my pinmodes are in setup
The sketch compiles and displays temp/humidity, just won't hold the Led's high between thresholds

When I set the (temp) threshold1 to 60 ( lower limit), which is below my room temp and threshold3 to 80(upper limit), Ledpin8 just flashes once and goes low, never comes on again, unless restart. I wonder if my IF statements are right?  At least a LED comes on. The prog prints temp/humidity OK

Code:

#include <dht11.h>

dht11 DHT11;

void setup()
{
  DHT11.attach(2);
  Serial.begin(9600);
  
  
}

void loop()
{  const int LEDPIN8 = 8;       // Temp
  const int LEDPIN9 = 9;       // Humidity
 pinMode (LEDPIN8, OUTPUT); // Temp
 pinMode (LEDPIN9, OUTPUT); // Humidity
  
const int THRESHOLD1 = 60;   // Temp lower limit turn on..60
const int THRESHOLD3 = 100;   // Temp upper limit turn off
const int THRESHOLD2 = 50;  // humidity lower limit turn on
const int THRESHOLD4 = 75;   // humidity upper limit turn off
float Temperature;
float Humidity;


  Serial.println("\n");

  int chk = DHT11.read();

  Serial.print("Read sensor: ");
  switch (chk)
  {
  case 0:
    Serial.println("OK");
    break;
  case -1:
    Serial.println("Checksum error");
    break;
  case -2:
    Serial.println("Time out error");
    break;
  default:
    Serial.println("Unknown error");
    break;
  }

  Serial.print("Humidity (%): ");
  Serial.println((float)DHT11.humidity, DEC);

 
  Serial.print("Temperature (F): ");
  Serial.println(DHT11.fahrenheit(), DEC);
  
  
  
  
  //Temperature
  
  Temperature = (DHT11.fahrenheit(), DEC);
  
   if (DHT11.fahrenheit(), DEC < THRESHOLD1)           // temp turn on...less than 60
    digitalWrite(LEDPIN8, HIGH);
    //delay(4000);//works on temp
    
    if (DHT11.fahrenheit(), DEC > THRESHOLD3)           // temp turn off.. more than 80
    
    digitalWrite(LEDPIN8,LOW);
  
    
    //Humidity
    
    Humidity = (DHT11.humidity, DEC);
    
     if (DHT11.humidity, DEC < THRESHOLD2)           // Humidity turn on les than 50
    digitalWrite(LEDPIN9, HIGH);
    //delay(2000);//no work on hum
    

  if (DHT11.humidity, DEC > THRESHOLD4)           // Humidity turn off.. more than 75
    
    digitalWrite(LEDPIN9,LOW);


  

  
  delay(200);
}

Moderator edit: CODE TAGS

I want to compare it to the threshold1 to turn on the LED

Using a DHT11 on arduino1280, Trying to turn on LED when threshold met
When I compile it stops on
Temperature = (Temperature (°F): );
and says stray "/" in program, I can't find it
Sorry don't understand code tags yet, don't see #






#include <dht11.h>

dht11 DHT11;

void setup()
{
  DHT11.attach(2);
  Serial.begin(9600);
 
 
}

void loop()
{  const int LEDPIN8 = 8;       // Temp
  const int LEDPIN9 = 9;       // Humidity
 pinMode (LEDPIN8, OUTPUT); // Temp
 pinMode (LEDPIN9, OUTPUT); // Humidity
 
{const int THRESHOLD1 = 80;   // Temp
const int THRESHOLD2 = 50;  // humidity
Temperature = (Temperature (°F): );

  Serial.println("\n");

  int chk = DHT11.read();

  Serial.print("Read sensor: ");
  switch (chk)
  {
  case 0:
    Serial.println("OK");
    break;
  case -1:
    Serial.println("Checksum error");
    break;
  case -2:
    Serial.println("Time out error");
    break;
  default:
    Serial.println("Unknown error");
    break;
  }

  Serial.print("Humidity (%): ");
  Serial.println((float)DHT11.humidity, DEC);

 
  Serial.print("Temperature (°F): ");
  Serial.println(DHT11.fahrenheit(), DEC);
 
 
 
 
  //Temperature
 
  Temperature = (DHT11.fahrenheit(), DEC);
 
   if (Temperature < THRESHOLD1)           // heat
    digitalWrite(LEDPIN8, HIGH);
    else
    digitalWrite(LEDPIN8,LOW);
  else
    digitalWrite(LEDPIN8,LOW);
   
   
    //Humidity
   
    Humidity = (float)DHT11.humidity, DEC);
   
     if (Humidity > THRESHOLD2)           // Humidity
    digitalWrite(LEDPIN9, HIGH);

  else
    digitalWrite(LEDPIN9,LOW);


 

 
  delay(20000);
}

Howdy I’m a beginner
I am trying to use a DHT11 to monitor temp/humidity ( turn on Led8 when temp drops below threshold1 and use threshold2 for humidity-not entered yet, if I can figure temp first then humid.
I have declared threshold1, but keep getting this error when compiling
Threshold1 was not declared in this scope
Using arduino 1280 and arduino 1.01
Thanks for all replies






#include <dht11.h>

dht11 DHT11;

void setup()
{
  const int LEDPIN8 = 8; // heat
  const int LEDPIN9 = 9;// mister
  pinMode (LEDPIN8, OUTPUT); // Heat 

  pinMode (LEDPIN9, OUTPUT); // Mister
  DHT11.attach(2);
  Serial.begin(9600);
 

  const int THRESHOLD1 = 90;   // Heat
  const int THRESHOLD2 = 90;  // Mister

 
}



void loop()
{
  Serial.println("\n");

  int chk = DHT11.read();

  Serial.print("Read sensor: ");
  switch (chk)
  {
  case 0:
    Serial.println("OK");
    break;
  case -1:
    Serial.println("Checksum error");
    break;
  case -2:
    Serial.println("Time out error");
    break;
  default:
    Serial.println("Unknown error");
   
   
  }



  Serial.print("Temperature (°F): ");
  Serial.println(DHT11.fahrenheit(), DEC);
if (chk < THRESHOLD1)           //
    digitalWrite(LEDPIN8, HIGH);

  else
    digitalWrite(LEDPIN8,LOW);







  delay(20000);
}

I have built this simple cloud charge monitor   http://www.techlib.com/electronics/cloud.htm
I have it hooked up to an arduino uno with 9 LED’s
 that light up as the charge  progressive, works good with a comb run thru your hair and over the pan. We are in a drought right now, so I am waiting for a real T-storm for the real test.
The arduino powers the circuit and will run off the laptop, so no fear of lightning coming in from the wall. I have serial print set up in the arduino code and can read it in serial monitor, I just need to figure the code in VB to get the data into a text box, then I can work on gauges and graphs. I am using com 2 default settings. If you have a short program in VB to do that and would share it, it would be much appreciated. Just a hump to get over
Thanks

I have learned how to write programs in Assembly, Gwbasic, Quickbasic back in 1989, but that was many brain cells ago. Almost like starting over again. Thinking about C# since it is close to VB. I am wanting to make gauges and graphs from the arduino serial out.

I want to read the serial out from the arduino and make fancy displays in VB. I just don't want to waste time learning VB if there is a lot of problems using  it with arduino. So far i have installed visual micro and it did not work, Thanks for that reply.

I have installed VB 2010 and was wondering if people are having good luck with it.
There is a plugin called visual micro, that is for arduino in VB, any luck with that?
Thanks for all replies.

Yes I have tried serial monitor. I just want to get fancy windows.LOL
Thanks for the replies. Think I will try VB-2010 it's free.

Howdy I am new to arduino. I have written my first sketch to read the analog 0 port and turn on several LED’s. I would like to know which programming software is the easiest way to send the info to the computer to print on the screen ( VB-6, C++,VB-2010. Etc.). Right now all I want to do, is print the values from analog in. I have Visual basic-6
Thanks for any help

Thanks

Can the Tx (pin 1) on a uno board be used as a digitalwrite output pin?
Thanks