Mega 2650 dht11 sensor & lcd 16x2 display

Projects Programming
1

Hey everyone, Looking for the proper source code to display temp and humidity. I'm using the Audrino Mega 2650. I found a bunch for the Uno card, but not one for the mega card. I've attached a pic of my wiring and I'm also unsure if I have the proper 10k resistor for the dht11 sensor. Any and all help is appreciated. Been googling and searching youtube with no luck.

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2

DHT libraries that support the UNO also support the MEGA. The library example sketches will do what you ask for.

3

Thank you, I'm getting close. I think it's just identifying the pin out for the display. I'm getting this error message... no matching function for call to 'LiquidCrystal::LiquidCrystal(int, int).

Can anybody take a peek at this and tell me what I'm doing wrong?

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(20, 21, 12,);
#define DHTTYPE DHT11

4

I'm a newbie too but I use the following.

#include <Wire.h>                                 // include wire library
#include <hd44780.h>                              // main hd44780 header
#include <hd44780ioClass/hd44780_I2Cexp.h>        // i2c expander i/o class header

const int LCD_COLS = 20;
const int LCD_ROWS = 4;

hd44780_I2Cexp lcd;                               // declare lcd object: auto locate & auto config expander chip

void setup()
{
  lcd.begin(20, 4);
  lcd.init();
  lcd.backlight();
}

You may have to change the COLs to 16 and ROWs to 2. Don't forget to download the library.

Hope this helps.

Tony

5

Thank you Tony!!!!! Is that all of the code? I see nothing for the sensor.

6

Try this...

The pin ("4" below) may change in your case. No sure what you plan on using.

#include <dht11.h>
#define DHT11PIN 4

dht11 DHT11;

void setup()
{ 
}

I've only used the DHT22 but found the above online. Give it a try. Remember to download the library before you try to compile.

7

j1mmi3b:
Thank you, I'm getting close. I think it's just identifying the pin out for the display. I'm getting this error message... no matching function for call to 'LiquidCrystal::LiquidCrystal(int, int).

Can anybody take a peek at this and tell me what I'm doing wrong?

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(20, 21, 12,);
#define DHTTYPE DHT11

It certainly looks like a typo, with the comma after the 12.

8

You can get the code from Arduino displays temperature and humidity from DHT11 on LCD I2C , The tutorial uses Uno, but it works with Mega also. The wiring are the same

9

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