arduino dht11 lcd display free sample

It’s a low cost digital temperature and humidity sensor module which based on the new DHT11 sensor. The Grove DHT11 sensor requires only one I/O pin for the communication with the master device.

The Grove DHT11 temperature & humidity sensor uses the upgraded version of DHT11. In this version, resistive humidity components is replaced by capacitive humidity components, temperature and humidity measurement ranges are wider and temperature resolution is higher.

Seeed Studio provides a nice open source library for their LCD module which can be installed from Arduino IDE library manager (Sketch —> Include Library —> Manage Libraries …, in the search box write “grove lcd” and install the one from Seeed Studio).

They (Seeed Studio) also provide a library for their Grove DHT11 sensor but I recommend to use the one given by Adafruit Industries which can be installed also through library manager (in the search box write “dht sensor” and choose the one written by Adafruit) or manually, download links are below:

DHT11 is a Humidity and Temperature Sensor, which generates calibrated digital output. DHT11 can be interface with any microcontroller like Arduino, Raspberry Pi, etc. and get instantaneous results. DHT11 is a low cost humidity and temperature sensor which provides high reliability and long term stability.

In this project, we will build a small circuit to interface Arduino with DHT11 Temperature and Humidity Sensor. One of the main applications of connecting DTH11 sensor with Arduino is weather monitoring.

We will see the circuit design of DHT11 interfacing with Arduino. The DHT11 Humidity and Temperature sensor comes in two variants: just the sensor or a module.

Coming to the design, the data pin of the DHT11 Sensor is connected to the Pin 11 of Arduino. A 16 x 2 LCD display is used to display the results. The control pins of LCD i.e. RS and E (Pins 4 and 6 on LCD) are connected to pins 4 and 5 of Arduino. The data pins of LCD i.e. D4 to D7 (pins 11 to 14 on LCD) are connected to pins 0 to 3 on LCD.

NOTE: For ease of connection, we have connected the DHT11 Sensor Module at the ICSP pins of the Arduino as it provides adjacent VCC, DATA and GND pins. This type of connection is not necessary and you can connect the data pin of sensor to normal Digital I/O pins.

DHT11 is a part of DHTXX series of Humidity sensors. The other sensor in this series is DHT22. Both these sensors are Relative Humidity (RH) Sensor. As a result, they will measure both the humidity and temperature. Although DHT11 Humidity Sensors are cheap and slow, they are very popular among hobbyists and beginners.

The DHT11 Humidity and Temperature Sensor consists of 3 main components. A resistive type humidity sensor, an NTC (negative temperature coefficient) thermistor (to measure the temperature) and an 8-bit microcontroller, which converts the analog signals from both the sensors and sends out single digital signal.

DHT11 Humidity Sensor consists of 4 pins: VCC, Data Out, Not Connected (NC) and GND. The range of voltage for VCC pin is 3.5V to 5.5V. A 5V supply would do fine. The data from the Data Out pin is a serial digital data.

The following image shows a typical application circuit for DHT11 Humidity and Temperature Sensor. DHT11 Sensor can measure a humidity value in the range of 20 – 90% of Relative Humidity (RH) and a temperature in the range of 0 – 500C. The sampling period of the sensor is 1 second i.e.

A simple project is built using Arduino UNO and DHT11 Humidity and Temperature Sensor, where the Humidity and Temperature of the surroundings are displayed on an LCD display.

After making the connections, we need not do anything as the program will take care of everything. Although there is a special library for the DHT11 module called “DHT”, we didn’t use it. If you want to use this library, you need to download this library separately and add it to the existing libraries of Arduino.

The program written is based on the data timing diagrams provided in the datasheet. The program will make the Arduino to automatically read the data from the sensor and display it as Humidity and Temperature on the LCD Display.

Arduino UNO - LCD display and DHT11 sensor with temperarure and humidity measurement. When there is no datafrom the DHT11 sensor, the buzzer will be activated.

I have the dht11 reading and printing to lcd and serial monitor.I have the dht11 controlling two relays one for temp and one for humidity.When the relay turns on the dht11 stops sending readings and freezes and stops reading? Any way I can fix that ?thanks

The output is to the serial monitor, unless you have connected an LCD. The video will show you how to open the serial monitor if you don’t already know how to.

A quick question tho, do you have a tutorial on how to connect this to a wireless transceiver?? also in theory could i connect more then one humidity detector to an arduino in order to detect humidity from more then one spot? Thank you again and i’ve subscribed!

Hi Jose, you can definitely connect more than one sensor to a single Arduino. You would basically duplicate the code, and have a separate pins read the data from each sensor. As for connecting them to a wireless tranceiver, I’m sure it’s possible, but you would probably need to use another microcontroller as a hub to transmit the data. I haven’t tried it yet though, so don’t take my word for it!

Hello, I built my first arduino project (measuring the room temperature and humidity with the DHT11) during Christmas holidays. The readings of the values were shown on the screen of my laptop. The measured room temperature was correct, but the measured humidity was much too low (about 20%RH). What can be the reason for ithe low humidity? And how can the sensor (if needed) be recalibrated?

vcc is the left one, signal the middle one and ground is the round one, in case of a 3 pin DHT11. the diagram above is not right. i was getting the same problem here.

The diagram is correct for most three pin DHT11 modules. Depending on the manufacturer, the pins on the PCB might be different though. The pins should be labelled with S for signal and “-” or “GND” ground.

See the section “Output Humidity and Temperature Readings to an LCD Display” on a desktop… If you are viewing it on mobile, the full code might not display. Hope this helps

It sounds like you want to control the heater with the DHT11 and have the readings output to an LCD too… You can use the DHT11 to control the signal to a 5V relay, similar to what’s done in this article: https://www.circuitbasics.com/build-an-arduino-controlled-power-outlet/

Then you just need to add the code to initialize the LCD, include the LiquidCrystal library, and change the “serialprint()” functions to “lcd.print(). We have another article on setting up an LCD on the Arduino if you need help with it: https://www.circuitbasics.com/how-to-set-up-an-lcd-display-on-an-arduino/

i didnt have any trouble interfacing the arduino, lcd and the dht11 sensor and my codes were quite right since when i run it, nothing’s odd in the output. but when i connect the relay,in which an ac device is connected, as an output that turns on after a couple of minutes, the temperature and humidity dislayed on the lcd becomes odd, like chinese and numbers, after some time. i checked my codes but i cant figure out whats wrong with it.

please help me.. i won’t get Alarm temperature and humidity..and show in lcd display 16×2.. and changeing temperature, humidity alarm set point HOW IS DO… PLEASE HELP ME.

Any comments about DHTLib v0.1.14 vs. v0.1.21, and why this simple Arduino sketch works in the former, but not the latter? The brief history in the cpp file header for v0.1.21 looks like it took care of a few issues so my first instinct is to use that, but again, it results in all zero readings. Anyway, if no comments, well, I’ll have to take a look through the diffs between the two versions to see what might be causing the issue.

vcc is the left one, signal the middle one and ground is the right one, in case of a 3 pin DHT11. the diagram above is not right. i was getting the same problem here.

The diagram is correct, but your particular DHT11 could have a different pinout depending on the manufacturer. The DHT11 I used is from Keyes, what type do you have?

Are you using the four pin DHT11? If so you’ll need to put a 10K Ohm resistor between the Signal line and Vcc. I just added another diagram to the post to make it a bit clearer. That may be causing your issue.

Thanks a lot, may you please help me out, I am using a Mega 2560 with a DHT11 sensor, my problem is that both temperature and humidity reading is just being reed as 0.00 and they are not changing. What might i be doing wrongly, I have even tried the code that accompanies these tutorials

This seems like a really simple setup, but I’ve been having a lot of trouble setting this up. Have there been changes to this library? I have downloaded it, but arduino still refuses to recognize dht or any of the related functions, like temperature/humidity. It had a lot of trouble with line 3, dht DHT;. Any advice?

Hi, you mentioned you added a piece of code to show the “degree” symbol,” lcd.print((char)223)”, can you tell me if the number 223 is from the ASCII table.

vcc is the left one, signal the middle one and ground is the right one, in case of a 3 pin DHT11. the diagram above is not right. i was getting the same problem here.

i am doing fire alarm system using dht and lcd and GSM sim800l how can i make argument to send message from gsm if the sensor reading is higher that the set temp and how to declare it thanks for your response

I am very happy to inform you that I fixed successfully the temp and humidity project with LCD display. I would like to subscribe but cannot find the link.Many thanks

C:\Users\mhine\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.2.0\cores\esp8266/Arduino.h:227:63: error: cannot convert ‘volatile uint32_t* {aka volatile unsigned int*}’ to ‘volatile uint8_t* {aka volatile unsigned char*}’ in initialization

Hi. I have the same issue with the same board. Did you get it to succeed in the end? I would be interested, but I feel that it may be a compatibility issue with a 3rd-party board. I have tried the exact code with other Arduinos that I have and it works just fine.

I get this same error when I try to use the Arduino 101 instead of the Uno. I think the library doesn’t support the board. I would try finding a different DHT library, there are several others out there.

I Have issues with the Arduino recognizing the file dht.h. Was told no such file exist, meanwhile I have uploaded the zip file into the Arduino IDE, which showed in the file directory.

Did you use the library in the zip file from the post, or did you download it from the Arduino.cc page? Version 0.1.21 has some issues and doesn’t appear to work. The zip file in the post is version 0.1.14, and it does work. Also, are you using the Uno, or another board? I couldn’t get the library to work on my Arduino 101…

In this language, does declaring an object variable (as in “dht DHT;”) automatically instantiate it? I am more used to other languages that would need to follow the declaration with something along the lines of “DHT = new dht(params, for, constructor);” Does this normally go without saying in C++, or is this something the Arduino environment automatically adds at the preprocessing** stage?

**: If not “preprocessing,” then whatever else Arduino parlance calls the process of converting/expanding the “Processing” (??) or “Wiring” (???) code into standard C/C++ ????

hey can you pls help me how to use rf module with the above project. i am using two arduino uno, DHT11, LCD, RF transmitter and receiver. please can u give me a code to display temperature and humidity on the receiver side lcd…

I connected the LCD and the DHT11 and copied and pasted the code. It uploaded and then I look at my LCD and all I see are white boxes on the top of the display. Can anyone help me?

I copied this exactly and got it to display temperature and humidity, but it flashes -999 for temp and -999 for humidity every other second. For example, it will display correct readings for one second, then the -999 for both readings the next second.. Flashing between the two. Any ideas why it might be doing this. I have been playing with the code, rechecking pins, etc, but I cant seem to pinpoint the problem. Any input is appreciated.

hello, i need some help, i want code for, if i m sending message from mobile (e.g. ABC) to arduino via gsm module then the values of temperature and humidity receiving specific number

I have arn Arduino y module that I am using to trgger an extractor fan in a shower. I was wondering whether this humidity sensor could be used to simply close the 5v circuit so teh fan runs on until teh humidity is below a set vaue. Is that possible simply?

Hi.recently i conduct sensor circuitry.in source code,i notice that it use \xF8 to display temperature in degree celcius.what is the function of that?

I followed the instructions exactly, wiring was good, code was an exact replica of that given. Everything was correct, but I got -999 error message every time. I was using a three pin sensor, triple checked my wiring against the diagram. I increased the delay time to 3000ms. I was definitely using the correct older version of the library. After throwing out the sensor thinking it faulty, I have since discovered that the diagram above is does not apply to every dht11, that there are some where the pins are in a different order.

What does this mean? in every other arduino program I can find that uses additional libraries, the library is called first, then the code goes straight on to initialising the variables and describing the setup. I have not been able to find any other mention of the library name mentioned twice like this. A few people have asked about this, with no answers given. I cant even search for it because I dont know what to search by.

You will get 100% humidity if you put the sensor in water and it works. Use an SHT31-D breakout board to detect humidity and temperature. I’m sure you didn’t mean you are going to submerge the sensor. The SHT31-D is more accurate and easier to install and costs about the same as the DHT11 /22 both of which really aren’t accurate at all.

Ine is set up exactly as you show. I get -999.00 for both humidity and temperature. I have 2 different sensors (both DHT11) and I get the same readings. I even set this up on an RPI 3B+ and the readings were similar. 1.0 temp and humidity. What am I doing wrong?

I can not keep my display from blinking the temp and humidity values. It displays the value but blinks back and forth to -999.00. Thanks for the help I’m new

Still getting -999.00 on both temperature and humidity with LCD. If I connects ONLY DTH11 to Arduino with serial monitor it works fine, BUT if I connect it to LCD as described above it shows -999.00 In both LCD and serial monitor. It looks like it disables the DTH11 when connected to LCD. It does not work with dely(2000); or any other value.

i don’t know why but the LCD shows me white circles and within them the text is written also the temp and humidity are a constant 0 even with the serial monitor

It’s good idea for projects. I am thinking of building my own weather unit soon. Please can someone help me with a simulation circuit that will show the response graphs of dht11 for temperature and humidity

How would you configure Celsius to Fahrenheit when doing the LCD version? I read others commenting how with out the LCD but not with the code for using the LCD.

Welcome to ProteShea – in this project, we’re going to interface a DHT11 temperature and humidity sensor, and display the data on a 16×2 LCD. If you haven’t read

Please see Project 9 on how to interface the 16×2 LCD in 4-bit mode. You should have pins 4, 6, and 11 – 14 of the LCD connected to Uno pins 2, 3, and 4 – 7, respectively.

The 20×4 LCD adds two extra rows and four extra columns per row compared to the 16×2 LCD. Similar to the 16×2, the 20×4 LCD uses the Hitachi controller so the commands and interfaces are the same. It also has the same 16-pin header, allowing you to unplug the 16×2 LCD and plug in the 20×4 without changing any wiring. The only thing we have to change is one line of code, lcd.begin(20, 4), which specifies the columns (first argument) and rows (second argument) of the LCD.

There are different types of DHT sensors such as the DHT11, DHT21, DHT22, DHT33, and DHT44. They all measure both temperature and humidity, but the difference lies mostly in their accuracy and sampling rate. For example, we show a side-by-side comparison in the table below of the two most popular DHT sensors, DHT11 and DHT22. The DHT22 has a better accuracy and range, but it has a slower sampling rate, it’s bigger in size, and double the cost of the DHT11.

We are using a 3-pin DHT11 sensor as shown in the image below. The pins are “+”, “OUT”, and “-.” The sensor can be supplied with both +5Vdc or +3.3Vdc – we’ll be supplying +5Vdc to it.

We are mounting the DHT11 sensor to the 2.54mm pitch section of Modulus with a right-angle (R/A) female header, as shown in the image below. Solder the 4-pin R/A female header to the edge of the board. Next, solder a 4-pin male header adjacent to the female header. Once you have the headers soldered on, flip the board over and make a solder bridge between the adjacent pins of the headers.

Once the wiring is complete and the FuelCan is powered up, we can now load the sketch onto the Uno. The first sketch is used with the 16×2 LCD. The second sketch is used with the 20×4 LCD. The DHT11 sensor is sampled every two seconds since sampling faster causes errors.

In this Arduino Tutorial we will learn how to use the DHT11 or the DHT22 sensor for measuring temperature and humidity with the Arduino board. You can watch the following video or read the written tutorial below for more details.

The DHT22 is the more expensive version which obviously has better specifications. Its temperature measuring range is from -40 to +125 degrees Celsius with +-0.5 degrees accuracy, while the DHT11 temperature range is from 0 to 50 degrees Celsius with +-2 degrees accuracy. Also the DHT22 sensor has better humidity measuring range, from 0 to 100% with 2-5% accuracy, while the DHT11 humidity range is from 20 to 80% with 5% accuracy.

There are two specification where the DHT11 is better than the DHT22. That’s the sampling rate which for the DHT11 is 1Hz or one reading every second, while the DHT22 sampling rate is 0,5Hz or one reading every two seconds and also the DHT11 has smaller body size. The operating voltage of both sensors is from 3 to 5 volts, while the max current used when measuring is 2.5mA.

The DHTxx sensors have four pins, VCC, GND, data pin and a not connected pin which has no usage. A pull-up resistor from 5K to 10K Ohms is required to keep the data line high and in order to enable the communication between the sensor and the Arduino Board. There are some versions of these sensors that come with a breakout boards with built-in pull-up resistor and they have just 3 pins.

First we need to included the DHT library which can be found from the Arduino official website, then define the pin number to which our sensor is connected and create a DHT object. In the setup section we need to initiate the serial communication because we will use the serial monitor to print the results. Using the read22() function we will read the data from the sensor and put the values of the temperature and the humidity into the t and h variables. If you use the DHT11 sensor you will need to you the read11() function. At the end we will print the temperature and the humidity values on the serial monitor.

Start Visuino as shown in the first picture Click on the "Tools" button on the Arduino component (Picture 1) in Visuino When the dialog appears, select "Arduino UNO" as shown on Picture 2

Double click on the "LiquidCrystalDisplay1" and in the Elements window:drag "Text Field" to the left side, then in the properties window set text to "TEMP:" and width to 20

If you power the Arduino UNO module, the LCD Display will start to show the Temperature and Humidity values. In case you dont see any text make sure you adjust the brightness using a potentiometer.

This article is a guide for the popular DHT11 and DHT22 temperature and humidity sensors with the Arduino. We’ll explain how it works, show some of its features and share an Arduino project example that you can modify to use in your own projects.

The DHT11 and DHT22 are very similar, but differ in their specifications. The following table compares some of the most important specifications of the DHT11 and DHT22 temperature and humidity sensors. For a more in-depth analysis of these sensors, please check the sensors’ datasheet.

In the loop(), at the beginning, there’s a delay of 2 seconds. This delay is needed to give enough time for the sensor to take readings. The maximum sampling rate is two seconds for the DHT22 and one second for the DHT11.

After uploading the code to the Arduino, open the Serial Monitor at a baud rate of 9600. You should get sensor readings every two seconds. Here’s what you should see in your Arduino IDE Serial Monitor.

If you’re trying to read the temperature and humidity from the DHT11/DHT22 sensor and you get an error message in your Serial Monitor, follow the next steps to see if you can make your sensor work (or read our dedicated DHT Troubleshooting Guide).

Power: the DHT sensor has an operating range of 3V to 5.5V (DHT11) or 3V to 6V (DHT22). If you’re powering the sensor from the a 3.3V pin, in some cases powering the DHT with 5V solves the problem.

Bad USB port or USB cable: sometimes powering the Arduino directly from a PC USB port is not enough. Try to plug it to a USB hub powered by an external power source. It might also help replacing the USB cable with a better or shorter one. Having a USB port that supplies enough power or using a good USB cable often fixes this problem.

Power source: as mentioned in the previous tip, your Arduino might not be supplying enough power to properly read from the DHT sensor. In some cases, you might need to power the Arduino with a power source that provides more current.

Wrong baud rate or failed to upload code: if you don’t see anything in your Arduino IDE Serial Monitor double-check that you’ve selected the right baud rate, COM port or that you’ve uploaded the code successfully.

You need to install the Adafruit Unified Sensor driver library. In your Arduino IDE, type in the search box “Adafruit Unified Sensor“, scroll all the way down to find the library and install it.

The DHT11 and DHT22 sensors provide an easy and inexpensive way to get temperature and humidity measurements with the Arduino. The wiring is very simple – you just need to connect the DHT data pin to an Arduino digital pin.

This tutorial shows how to use the DHT11 and DHT22 temperature and humidity sensors with the ESP32 using Arduino IDE. We’ll go through a quick introduction to these sensors, pinout, wiring diagram, and finally the Arduino sketch.

The DHT11 and DHT22 are very similar, but differ in their specifications. The following table compares some of the most important specifications of the DHT11 and DHT22 temperature and humidity sensors. For a more in-depth analysis of these sensors, please check the sensors’ datasheet.

To read temperature and humidity from the DHT sensor, we’ll use an example based on the Adafruit DHT library. Copy the following code to your Arduino IDE.

Then, you need to select the DHT sensor type you’re using. The library supports DHT11, DHT22, and DHT21. Uncomment the sensor type you’re using and comment all the others. In this case, we’re using the DHT22 sensor.

If you’re trying to read the temperature and humidity from the DHT11/DHT22 sensor and you get an error message in your Serial Monitor, follow the next steps to see if you can make your sensor work (or read our dedicated DHT Troubleshooting Guide).

Power: the DHT sensor has an operating range of 3V to 5.5V (DHT11) or 3V to 6V (DHT22). If you’re powering the sensor from the ESP32 3.3V pin, in some cases powering the DHT with 5V solves the problem.

Wrong baud rate or failed to upload code: if you don’t see anything in your Arduino IDE Serial Monitor double-check that you’ve selected the right baud rate, COM port or that you’ve uploaded the code successfully.

You need to install the Adafruit Unified Sensor driver library. In your Arduino IDE, type in the search box “Adafruit Unified Sensor“, scroll all the way down to find the library and install it.

With this tutorial you’ve learned how to get temperature and humidity readings from a DHT11 or DHT22 sensor using the ESP32 with Arduino IDE. Getting temperature and humidity readings with the Adafruit DHT library is very simple, you just use the readTemperature() and readHumidity() methods on a DHT object.

Now, you can take this project to the next level and display your sensor readings in a web server that you can consult using your smartphone’s browser. Learn how to build a web server with the ESP32 to display your sensor readings: ESP32 DHT11/DHT22 Web Server – Temperature and Humidity using Arduino IDE.

This is a simple temperature and humidity monitor device made by use of components like lcd keypad shield , dht11 sensor and arduino mega. The temperature accuracy of dht11 not up to the point but it’s good.

Hello friends! Welcome back to ElectroDuino. This blog is based on DHT11 Temperature and Humidity Sensor Arduino Code with LCD Display. Here we will discuss Introduction Temperature and Humidity Monitoring System, Circuit diagram, Working and DHT11 Temperature and Humidity sensor Arduino Code with LCD Display.

In the previous blog posts, we were learning about the “DHT11 Temperature and Humidity Sensor Module” and “Interfacing DHT11 with Arduino”. In this project, we will discuss how to make a Temperature and Humidity Monitoring System. Where we will print the Temperature and Humidity value on a 16×2 LCD display using DHT11 and Arduino. DHT11 is the cheapest humidity and temperature sensor, it provides high reliability and long-term stability output. This is a very small and portable Temperature and Humidity Monitoring system so we can use it at home, office, school, etc. places. It gives us the Temperature and Humidity value of around it 24 x7. Here we will build this system and learn how to write the DHT11 Temperature and Humidity Sensor Arduino Code with LCD Display.

Before writing the Arduino Code we need to install two Libraries in our Arduino IDE Software, one is ” dht.h ” DHT11 sensor Library and Another one is “LiquidCrystal.h” 16×2 LCD Display Library You can Download the Library file by click on the Download Button.

In this session we will create a device that can measure the temperature and humidity in the environment and display the results in real time on a LCD screen.

Put libraries “dht11” and “LiquidCrystal_I2C” into Arduino IDE’s libraries folder. If you don’t know how to load libraries, please refer to Experiment 12 for details.

Once you are familiar with Arduino, you can even add network module to your controller to allow you to post the real-time data collected to an online platform like weibo or twitter.

I"m newbie in the Arduino world so I thought as a good practice why not trying to display the temperature and humidity on the LCD which I did so now I"m sharing with whomever interested.

To connect the DHT11 sensor and the LCD display, please refer to tutorials (lesson 10 DHT11 Temperature and Humidity Sensor and lesson 13 LCD Display)