Temperature and humidity are widely used as indicators of environmental conditions. This project will use an Arduino board to measure ambient temperature and humidity, displaying the results on a 16x2 LCD. This Celsius scale thermometer and percentage scale humidity measure project

uses DHT11 temperature and humidity measurements in combination with Arduino undo. Another project that I worked on previously involved designing a digital thermometer based on the temperature sensor LM35. There are three main parts to this project: in one, a humidity and temperature sensor (DHT11) detects the humidity and temperature. Second, it determines the temperature and humidity according to DHT sensor data and converts them into percentages and Celsius values. The third component is an LCD display that displays humidity and temperature. Serial communication is used in working on this project. An Arduino first sends a start signal to the DHT module, which then transmits temperature and humidity data back to the Arduino. Two humidity and temperature measurements are collected and extracted by Arduino and sent to a 16x2 LCD. The DHT11 sensor module was used in this project. An integrated humidifier and thermometer with a calibrated digital output are featured on the module. The DHT11 sensor module provides a digital output signal that is calibrated to measure humidity and temperature. DHT11's high accuracy and long-term stability guarantee high reliability and long-term stability.

Incorporated into the 4-pin single row package is an eight-bit microcontroller that has an 8-bit resistive humidity and temperature measurement component that is cost-effective, has a fast response time, and is available in a 4-pin single row package. Single wire serial communication is the method used by the DHT11 module. A pulse train of data is transmitted by this module over a specific period of time. An initialization command with a time delay is required before data can be sent to the Arduino. And the total processing time is four milliseconds. In this process, there are 40 bits of data transmitted, and the format is as follows: Eight-bit integral RH + eight-bit decimal RH + eight- bit integral T + eight-bit decimal T + an eight-bit checksum.

Circuit Diagram and Explanation

The temperature and humidity are displayed on the LCD directly connected to the Arduino in 4-bit mode. There are five LCD pins connected to the Arduino digital pins 2, 3, 4, 5, and 6. Additionally, RS, EN, D4, D5, and D7 are located in the LCD. Additionally, a 5k pull-up resistor is connected to digital pin 12 of the Arduino to connect the DHT11 sensor module. Complete Process: In order for DHT11 to be detected, Arduino sends a 18s delay high to low start signal. Once the data line is pulled up, the Arduino waits for DHT to respond. A low-voltage response signal will then be sent by the DHT to the Arduino after 80s, when it detects the start signal. In addition, DHT controllers pull up the data lines and keep them for 80s so that DHT can arrange and send data. A low voltage level on the data bus indicates that DHT11 is sending a response signal. After that is completed, the DHT again prepares the data lines for transmission by pulling up the 80s. Each bit of data is sent by DHT to the Arduino as a 50s low voltage signal, and whether the bit is a "0" or a "1" depends on the amount of high voltage signal. It's important to make sure the resistor value is cranked up because, if the DHTS is being installed at a distance of 20 meters, 5K pull-up resistors are recommended. Whenever the DHT is placed beyond 20 meters, a suitable pull-up resistor must be used.

A huge problem with humidity is also the sensitivity of other products to moisture, such as pharmaceuticals. In fact, humidity and temperature can drastically change the properties of the product and cause it to become useless, which is why items such as medical pills and dry powders are stored at precisely controlled conditions.