08-16-2017, 11:59 PM
interfacing of humidity sensor with 8051 microcontroller pdf
Abstract
This project is about a 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.DHT11 is a low cost humidity cum temperature sensor which has a digital output. Capacitive method is used for sensing the humidity and a thermistor is used for measuring the temperature. The sensor can sense relative humidity from 20% to 95% at a resolution of 5%. Temperature measurement is up to 50 C at a resolution of 2 C. The communication with the microcontroller is through a single wire.
Interfacing Humidity Sensors Family Models :
Atmel, NXP, Philips, 8051, 8052, 89C51, 89C52, 89S51, 89s52, 89C1051, 89C1051, 89C2051, AT89C4051, AT89S8252,l AT89C1051, AT89C2051, AT89C4051, P89C51RB+, P89C51RC+, P89C51RD+, P89C51RB2Hxx, P89C51RC2Hxx, P89C51RD2Hxx, P89C660, P89C662, P89C664, P89C668, P89C669, P89C51RA2xx, P89C51RB2xx, P89C51RC2xx, P89C51RD2xx, P89C60X2, P89C61X2,P89LV51RB2, P89LV51RC2, P89LV51RD2, P89V51RB2, P89V51RC2, P89V51RD2, P89V660, P89V662, P89V664.
About Humidity Sensors
Humidity sensor is used to detect the quantity of humidity from the environment. Humidity is measured into percentage and different types of Humidity Sensors are used to measure humidity. With interfacing with microcontrollers it becomes a standalone system to measure the percentage in the environment. Relative humidity/temperature and relative humidity sensors are configured with integrated circuitry to provide on-chip signal conditioning. Absorption-based humidity sensors provide both temperature and %RH (Relative
Humidity) outputs. On-chip signal processing ensures linear voltage output versus %RH. Sensor laser trimming offers +5 %RH accuracy and achieves 2 %RH accuracy with calibration. Packages are chemically resistant and operate in ranges of -40 C to 85 C [-40 F to 185 F] to accommodate harsh environments. They are following types:
Relative Humidity Sensor
Digital Humidity Sensor
Soil Humidity Sensor
Humidity And Temperature Sensor
Humidity Sensor Switch
Humidity Sensor probe
Applications Of Humidity Sensors 89C51 89C52 89S51 89S52 Microcontrollers
Relative Humidity Sensors are used in every fields. It has lots of importance and plays an important role in measuring Humidity from environment. They are also useful in all applications where humidity compensation is needed. It is used to develop following applications :
Office Automation Applications
Automotive Cabin Applications
Air Control Applications
Home Appliances Applications
Industrial Process Control Systems & Applications
Refrigeration And Cooling Systems & Applications
Drying Systems & Applications
Meteorology Applications
Battery Powered Systems Applications
OEM Assemblies and Applications
Offical Applications
Features Of Humidity Sensors
Full interchangeability with no calibration required in standard conditions
Instantaneous desaturation after long periods in saturation phase
Compatible with automatized assembly processes, including wave soldering, reflow and water immersion
High reliability and long term stability
Patented solid polymer structure
Suitable for linear voltage or frequency output circuitry
Fast response time
Individual marking for compliance to stringent traceability requirements.