The Engineering Projects

Introduction to DHT22

Hello friends, I hope you are all fine and will be doing something interesting in your life. in today's post, I am going to discuss Introduction to DHT22. It is a temperature and humidity measure sensing device. It is easily used but it needs a specific time for an operation. Its temperature measuring range is from -40 to +125 degrees Celsius with +-0.5 accuracy. This sensor measures moisture content and temperature. This sensor is easily connected to other microcontrollers. DHT22 plays an important role in our environment in measuring temperature and moisture. It is a low cost easy-to-use small sensor. This sensor is used at different weather stations to measure temperature and ratio of moisture in the air, in this way, they tell about temperature or rain prediction. In today's post, I will talk about its working protocol, pinout, application and interfacing with other microcontrollers. I will also share some links to projects where I have interfaced with other Arduino. If you have any queries about it please ask in the comment I will resolve your queries. So let's start with Introduction to DHT22.

Introduction to DHT22

• DHT22 is a low-cost humidity and temperature measuring sensor. It consists of thermister for temperature measurement and capacitive humidity sensor humidity measurement. The feature which gives importance then another sensor is that you can get data after two seconds.
• It is very easy to use, just connect the first pin from left with supply then get data from the second pin. Its last pin used for ground.

• It has higher accuracy and precision, due to this feature it can replace expensive imported SHT10 temperature and humidity sensor.
• This sensor is used to measure environment temperature and humidity to meet the high demand.
• This sensor has reliability and good stability. It is easy to combine with a special sensor Arduino expansion board, which is easy to use for temperature and humidity perception.
• DHT22 is digital humidity sensor, designed for analog sensor interfacing.
• It consists of 4.7 K to 10 K resistor, which can be used as pull up from data pin to Vcc.
• It has four pins with 0.1" spacing.

For better understanding now discuss its pin configuration.

DHT22 PINOUT & Description

There is main four pinout of DHT22 we use three pins which are discussed below with details.

No.	Pin Type	Parameters
1.	Vcc	This is Power Pin at this pin we apply 3.5 v to 5.0 volts.
2	Data	Through this pin, we get outputs both Temperature and Humidity through serial Data.
3	Ground	Ground Pin ( Connected to 0V or GND )

Better understanding lets see its pinout picture. Now discuss its working and its principle at which it works.

Working of DHT22

• Now discuss how it works, It consists of two main parts one measure temperature and other is used for humidity measurement it also has IC to send data to Microcontroller. Discuss these component ones by one.
  •  Humidity Sensing Component
    • For humidity measurement, it uses the humidity measurement component, which has two electrodes with moisture holding substrate between them.
    • As humidity changes, the conductivity of substrate changes or resistance between electrodes changes. This changes in resistance are measured, then processed by IC which make it ready to be rad by Microcontroller.
  • Temperature Measuring Component
    • To measure temperature this sensor uses an NTC temperature sensor or Thermistor.
    • A thermistor is a variable resistor that changes its resistance with a change of temperature. These sensors are made by sintering of semiconductive materials, such as ceramic or polymers in order to large change in a resistor with small changes in temperature. As temperature changes, there is a change in the value of resistance by which we measure the temperature of our environment.

For a better understanding of its working, Lets its picture. Now, discuss the features and specifications of DHT22.

Features & Specification of DHT22

These are some features of DHT22.

• The voltage it operates is 3.5v to 5.5v.
• Its operating current is 0.3v to 5.5.
• The protocol which it uses to send data is a serial transmission of data.
• Its temperature at which it operates is -40°C to 80°C.
• Its humidity range is 0% to 100%.
• Its temperature and humidity resolution are 16-bit.
• Its Accuracy is ±0.5°C and ±1%
• Its sampling rate is 0.5 Hz once every two seconds.
• Its dimensions are 27mm x 59mm x 13.5mm (1.05" x 2.32" x 0.53").
• It has four pins with 0.1" spacing.
• Its weight is 2.4g.
• It is a low-cost sensor. Its price is just $1 to $5.
• It has long term stability of ±0.5% per year.

Now we discuss the DHT22 Serial Data Transmission protocol by which it sends data.

DHT22 Serial Protocol

• DHT22 sensor is calibrated in industries it is designed for serial output data transmission. I have to interface it with Microcontroller for its serial data transmission.
• As you can see that the data pin is connected with an input-output pin of Microcontroller and 5k pull up resistor is used. This data pin sends output values of both temperature and humidity as serial data.

For a better understanding of serial transmission, let's see its picture. Now discuss DHT22 Arduino interfacing.

DHT22 Arduino Interfacing

• In given circuit diagram I have interfaced Arduino with DHT22. By providing source code to Arduino we can use it according to desire requirement and also can use it for temperature and humidity measuring purpose.

Application of DHT22

These are some application of DHT22.

• It is used for temperature and humidity measurement.
• It is used as a weather station to measure temperature and humidity in the air.
•  It is an automatic climate control sensor.
• It is also used as an environmental monitoring device.

So, friends, this was all about DHT22, if you have any query regarding it please ask in a comment. I will resolve your queries. Thanks for reading. Take care until the next tutorial.....

HC-06 Bluetooth Module Pinout, Datasheet, Features & Applications

Hello friends, I hope you all are doing great. In today's tutorial, we are gonna have a look at detailed Introduction to HC-06. HC-06 is a class 2 slave Bluetooth module designed for serial communication. Once it is paired to a master Bluetooth device such as PC, smartphones, and tablet, its operations become easier to the user. It sends and receives data in a bidirectional manner. HC-06 is used in different devices which works on Bluetooth for sending and receiving data. In today's post, we will have look at its pinout, working, circuit diagram, protocol, etc. I will also share some links of projects where I have interfaced it with Arduino and some other microcontroller. Friends if you have any questions please ask in comments I will try my best to solve your problems and I will give you a comprehensive answer. So let's start with basic Introduction to HC-06: 

Where To Buy?
No.	Components	Distributor	Link To Buy
1	HC-06	Amazon	Buy Now

HC-06 Bluetooth Module

• HC-06 is a Bluetooth module which is designed to work on serial communication. When we paired it with Bluetooth working devices such as smarts phones and tablet, its use becomes easier for device users.
• Its working depends on the wireless system, for sending and receiving data, it uses transceiver module RS 232 TTL. We do not use any cable for sending and receiving data for this module.

• The main feature of this Bluetooth module is that it can easily achieve serial wireless data transmission protocol.
• The frequency band at which it operates is 2.4 GHz ISM frequency.
• HC-06 adopts famous 2.0+EDR Bluetooth standard. The benefit of this standard is that data can be sent in less time interval. It can send data in 0.5 seconds of an interval. By this feature, the workload on Bluetooth chip can be reduced and a large amount of data can be sent in small time.

Lets discuss some parameters and pin configuration.

PIN Name	PIN No	Description	Pad type	Note
GND	13 21 22	Ground pot.	Vss
1V8	14	Integrated 1.8 V (+) supply with On-chip linear regulator output within 1.7-1.9 V.	Vdd
AIO0.	9	Programmable input/output line.	Bi-Directional
AIO1	10	Programmable input/output line.	Bi-Directional
PIO0	23	Programmable input/output line, control output for LNA (if fitted)	Bi-Directional RX EN
PIO1	24	Programmable input/output line, control output for PA(if fitted)	Bi-Directional TX EN
PIO2	25	Programmable input/output line.	Bi-Directional
PIO3	26	Programmable input/output line.	Bi-Directional
PIO4	27	Programmable input/output line.	Bi-Directional
PIO5	28	Programmable input/output line.	Bi-Directional
PIO6	29	Programmable input/output line.	Bi-Directional	CLK_REQ
PIO7	30	Programmable input/output line.	Bi-Directional	CLK_OUT
PIO8	31	Programmable input/output line.	Bi-Directional
PIO9	32	Programmable input/output line.	Bi-Directional
PIO10	33	Programmable input/output line.	Bi-Directional
PIO11	34	Programmable input/output line.	Bi-Directional
RESETB	11		CMOS Input with weak intemal pull-down
UART_RTS	4	UART request to send, active low.	CMOS output, tri-stable with weak internal pull-up
UART_CTS	3	UART clear to send, active low.	CMOS input with weak internal pull-down
UART_RX	2	UART Data input.	CMOS input with weak internal pull-down
UART_TX	1	UART Data output.	CMOS output, Tri-stable with weak internal pull-up
SPI_MOSI	17	Serial peripheral interface data input.	CMOS input with weak internal pull-down
SPI_CSB	16	Chip select for the serial peripheral interface, active low	CMOS input with weak internal
Vcc	12		3.3V

  Lets discuss pinout of HC-06.

HC-06 PINOUT

• There is four main pinout of HC-06, now we discuss each one by one and their function.
  • Vcc: This pin is used for input supply. At this pin, we provide an input voltage to HC-06.
  • GND: This pin use for ground.
  • TXD: By this pin, data is transmitted by the serial interface.
  • RXD: The purpose of this pin is to receive data by a serial interface.
• For better understanding lets have a look at the pinout diagram of HC-06.

Let's discuss some features of HC-06.

Features of HC-06

• These are some features of HC-06.
  • Bluetooth protocol which we connect with it is Bluetooth 2.0+ EDR.  2.0+ EDR is a standard Bluetooth protocol which is used.
  • It is at the Bluetooth class 2 power level.
  • USB protocol used for it is USB v 1.1/2.0.
  • The frequency on which it operates is a 2.4 GHz ISM frequency band.
  • The modulation mode which is used in this module is Gauss frequency Shift Keying.
  • Its transmitting power is = 4 dBm.
  • Its sensitivity rate is =-84 dBm at 0.1% Bit Error Rate.
  • The speed at which it transmits data is 2.1 Mbps (Max)/160 kbps (Asynchronous) and 1 Mbps/1 Mbps (Synchronous).
  • The Safety feature which it provides is authentication and encryption.
  • Its supported configuration is based on Bluetooth serial port (major and minor).
  • Its supply voltage is 3.3 V DC  and operating current is 50 mA.
  • Its operating temperature is 20 to 55?.
  • The weight of this module is 4g.
  • The dimensions of this module are 36.5*16 mm.
  • Its Default baud rate is 9600.
  • This module can also be used in SMD.
  • This module is made through ROHS process.
  • Board of this module PIN is half hole size.
  • It based upon CSR BC 04 Bluetooth technology.
  • It has a high-performance wireless transceiver system.
  • It is a Low-Cost module.
  • It has the external 8 Mbit flash.
  • It has a built-in 2.4 GHz antenna, the user does not need a test antenna.

Now, let's discuss the HC-06 Application:

Application of HC-06

These are some applications of HC-06

• HC-06 is a Bluetooth module, it is used in different electronic devices such as a mobile, laptop, personal computer, etc.
• It can also use in different industrial projects for sending and receiving data, Let's see pictures of HC-06 use in projects.

I hope you enjoyed today's tutorial on the HC-06 module.  If you need any help about this module, please ask in comments. Will meet you guys in the next tutorial. Till then take care.....