Saturday, January 23, 2016

How to Build Humidity Sensor (Hygrometer) DHT11 using AT89S51

ElcoHow. - Do you want to build by Humidity Sensor (Hygrometer) DHT11 using AT89S51? We think that there are application using microcontroller MCS51 or called 8051, like to build humidity that displayed in LCD.

Beside we will give you circuit schematic TransformerLess Power Supply 12V 100mA using Based on Humidity Sensor (Hygrometer) DHT11, AT89S51 and also component used, in here we also will give you global description about this circuit and also skill needed and other.

Electronic Circuit
Component List
  1. Humidity Sensor (Hygrometer) DHT11
  2. AT89S51
  3. Transistors
  4. LCD
  5. Capacitors
  6. Relay
  7. X-Tal
  8. Diode
  9. Push Button
  10. Array Resistor

Electronic circuit like in Figure 1 above is Humidity Sensor (Hygrometer) DHT11 using AT89S51 circuit. From this circuit, we can build simple humidity sensor based on 8051 microcontroller. Humidity sensor is also called hygrometer. This circuit can sense relative humidity (RH)  from 20% to 95% at an accuracy of 5%. The humidity information is displayed on a 16×2 LCD display. A relay is also provided which is set to be active when the humidity crosses a certain trip point. The circuit is mains operated and it is very easy to install. DHT11 is the humidity sensor used here.
Humidity Sensor (Hygrometer) DHT11
(Sumber: Screenshot of Circuitstoday)

According Circuitstoday site that published this circuit describe that the humidity sensor DHT11 is connected to P3.1 of the 8051 microcontroller. R8 pulls up the communication line between DHT11 and 8051. The relay is driven using P2.0 of the microcontroller. Transistor Q1 switches the relay. R0 is a pull up resistor and R7 limits the base current of Q1. D5 is just a free-wheeling diode. Data lines of the LCD display is interfaced to Port 0 of the microcontroller. Control lines RS, R/E and E are connected to P2.7, P2.6 and P2.5 pins of the microcontroller respectively. R4 sets the contrast of the display. R5 limits the current through the back light LED. C9 is a by-pass capacitor. C8, C10 and X1 are associated with the clock circuitry. C11, R6 and S2 forms the reset circuit..


To build Humidity Sensor (Hygrometer) DHT11 using AT89S51, you need some skill as follow:
  1. Basic soldering.
  2. Read a basic schematic.
  3. Assembling electronic component
  4. Design PCB layout
  5. Testing voltage and current
  6. Microcontroller programming
  7. Software and Hardware Microcontroller
Tools and Material

In this project, you must prepare some tools and material that used as the supporting to build Humidity Sensor (Hygrometer) DHT11 using AT89S51 as follow:

MCS51 USB Downloader

  1. Tools: soldering iron, cutter, multitester, Project Board, and MCS51 downloader.
  2. Material: Tin, PCB

When you want to realize this Humidity Sensor (Hygrometer) DHT11 using AT89S51 circuit into real application, you can build it as like design PCB layout using good software as like: Proteus. From ElcoHow site, you can choose many Proteus version that you can use to build circuit simulation and PCB layout design. Please visit some version of this software below:
How to do?

For more information about this project step-by-step you can follow this project of How to Build Humidity Sensor (Hygrometer) DHT11 using AT89S51 you can read below.
  1. Prepare electronic component listed, material and tools needed.
  2. Now, you write microcontroller listing program using MIDE-51 and also with this software convert this listing program to .hex format.
  3. And then you can realize this project using simulate firstly this circuit of Humidity Sensor (Hygrometer) DHT11 using AT89S51 using software Proteus ISIS.
  4. You also can try this project using Project Board before you realize into PCB layout. In this moment you can load your listing program to AT89S51 using MCS51 downloader.
  5. After you surely with this circuit work properly, now you can begin with design PCB using Proteus ARES.
  6. After designed, now you can make the PCB layout to put these components. You can make PCB by your self or order it according your PCB layout design.
  7. Put all component to the PCB layout and soldering all component.
  8. Now you can test, input and output voltage and current from this circuit. Please read caution below.
  9. Please see more about listing program and other of this Humidity Sensor (Hygrometer) DHT11 using AT89S51 here.
  • Do not put AT89S51 reverse to power supply, and make sure that the AT89S51 with +5VDC not more.

Thank you for your coming here in site, we hope the article above will help you to know more about your eletronic circuit design software and other. Please comment here when you want to share and other. Thank you.


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