DATA ACQUISITION SYSTEM USING AT89C51 PREM KUMAR M-TECH (PED) REG NO-1611110018
INTRODUCTION The main objective of this project is to developthe data acquisition system. In this project AT89c51 isused to develop the data acquisition system
WHAT IS DAQ? Data acquisition (DAQ) is the process of measuring an electrical or physical phenomenon such as voltage, current, temperature, pressure, or sound with a computer. DAQ systems either measure a physical parameter or take a specific action (sound an alarm, turn on a light, etc.) based on the data received.
DAQ SYSTEM A DAQ system consists of sensors, DAQmeasurement hardware, and a computer withprogrammable software sensor DAQ DEVICE COMPUTER DRIVER
BLOCK EXPLANATION First the sensor measures the physical quantity or electrical quantity like temperature, pressure, voltage or current. DAQ device which converts measured analog signal into digital signal. And it is also interfaced with PC. We can control the driver circuit by computer through data acquisition system.
PIN DESCRIPTIONCONNECTEDTO ADC TOSELECTSENSORCONNECTEDTO DRIVERCIRCUIT CONNECTED TO MAX 232 CONNECTED TO ADC
ANALOG TO DIGITAL CONVERTER ADC 0808 is 8 bit analog to digital converter, which uses successive approximation type conversion. Key specifications: Resolution 8 Bits Total Unadjusted Error ±½ LSB and ±1 LSB Single Supply 5 VDC Conversion Time 100 μs
MAX 232 The RS232 is not compatible with 89c51,we need a voltage converter to convert the RS232’s signals to TTL voltage levels that will be acceptable to the 89c51’s TxD and RxD pins. The MAX232 converts from RS232 voltage levels to TTL voltage levels, and vice versa.one advantage of the MAX232 chip is that we can use same power supply(+5V) for controller and MAX232.