DESIGN AND IMPLEMENTATION OF 4-CHANNEL DATA ACQUISITION SYSTEM

DESIGN AND IMPLEMENTATION OF 4-CHANNEL DATA ACQUISITION SYSTEM

Data acquisition system means acquiring data from any sensor (physical parameter value) and those values are displayed on the LCD. A Data Acquisition System is comprised of three parts; an I/O sub-system, a host computer (or equivalent circuit, here that is microcontroller) and the controlling software.

The purpose of data acquisition is to measure an electrical or physical phenomenon such as voltage, current, temperature, pressure, or sound. Many times it is required to monitor physical phenomena such as temperature, pressure, humidity, light intensity, sound intensity, force, etc. Such physical phenomena can be monitored by digital systems employing sensors. However sensors generally produce a change in resistance, voltage or current. All such phenomena can be converted into a change in voltage levels. Since the sensors and the subsequent signal conditioning circuits provide a proportionate change in voltage with respect to the phenomena, this cannot be directly interpreted by a digital system. A sensor is usually an analog voltage and can take any value between + 10 to -10 volts. However a digital signal has only two states. 1 (ON) or 0 (OFF). Thus it is required to have additional circuitry between the digital system and analog system that translates the analog signal in to a digital signal. Such conversion can be performed by an analog to digital converter.       

In this project we are interfacing four different sensors to the microcontroller with the help of ADC. To implement this overall project required components are microcontroller, MCP3204, temperature sensor, smoke (MQ-2 gas) sensor, variable resistor, LDR, LCD and LED’S. After interfacing all devices user has to develop one application program in EMBEDDED-C to get the final result. That is all sensors information is displayed on the LCD. For each sensor one set point is assigned in the application program. If the sensor value is crossing the set point one LED is turned ON. Here four sensors related four LED’S are there.

REQUIREMENTS:

HARDWARE REQUIREMENTS:

•   AT89S52
• MCP3204
• POTENTIOMETER
• LM35
• LDR
• SMOKE SENSOR
• LCD display

SOFTWARE REQUIREMENTS:

Ø  Functionality of all above components

Ø  Embedded C programming

Ø  KEIL-C COMPILER