PC BASED DATA LOGGER using RS485
Data acquisition is the process by which events in the real world are sampled and translated into machine-readable signals. Data acquisition typically involves sensors, transmitters and other instruments to collect signals, waveforms etc. to be processed and analyzed with a computer.
The components of data acquisition systems include appropriate sensors that convert any measurement parameter to an electrical signal, which is acquired by data acquisition hardware. Acquired data typically is displayed, analyzed, and stored on a PC. A data logger is any device that can be used to store data. This includes many data acquisition devices such as plug-in boards or serial communication systems which use a computer as a real time data recording system.
ADC is used to convert these analog parameters into digital values. These digital values are then passed to the controller. The data coming out from the controller will be displayed on LCD display. The parameters like temperature, voltage and light intensity are measured in this project.
Analog-to-digital converters are among the most widely used devices for data acquisition. Digital systems use binary values, but in the physical world everything is continuous i.e., analog values. Temperature, pressure (wind or liquid), humidity and velocity are the physical analog quantities. These physical quantities are to be converted into digital values for further processing. One such device to convert these physical quantities into electrical signals is sensor. Sensors for temperature, pressure, humidity, light and many other natural quantities produce an output that is voltage or current.
The analog parameters are read by their respective sensors, converted into corresponding digital data using ADC and passed to the microcontroller. The controller finally displays these values on the PC. The microcontroller continuously reads the values from ADC and displays the updated values on the PC. We are using RS485 for the long distance communication also the sensors can be placed with in a distance of 1 to 1.5 kms
APPLICATIONS OF RS485 :
- Multiple transceiver application.
- Low power application.
- Long distance capability up to 1.5 kms
SOFTWARE AND HARDWARE TOOLS:
- Keil compiler
- Microcontroller AT89S52.
- Sensors- LM35, LDR, voltage measuring circuit