1.1.1 EMBEDDED SYSTEM:
An embedded system is a special-purpose system in which the computer is completely encapsulated by or dedicated to the device or system it controls. Unlike a general-purpose computer, such as a personal computer, an embedded system performs one or a few predefined tasks, usually with very specific requirements. Since the system is dedicated to specific tasks, design engineers can optimize it, reducing the size and cost of the product. Embedded systems are often mass-produced, benefiting from economies of scale.
Personal digital assistants (PDAs) or handheld computers are generally considered embedded devices because of the nature of their hardware design, even though they are more expandable in software terms. This line of definition continues to blur as devices expand. With the introduction of the OQO Model 2 with the Windows XP operating system and ports such as a USB port — both features usually belong to "general purpose computers", — the line of nomenclature blurs even more.
Physically, embedded systems ranges from portable devices such as digital watches and MP3 players, to large stationary installations like traffic lights, factory controllers, or the systems controlling nuclear power plants.
In terms of complexity embedded systems can range from very simple with a single microcontroller chip, to very complex with multiple units, peripherals and networks mounted inside a large chassis or enclosure.
Fig.1. Example of Embedded System 1.2 AIM OF THE PROJECT:
This project is to design a data acquisition system through PC.
1.3 SIGNIFICANCE OF THE WORK:
The purpose of the project is to design a data acquisition system through PC. The main objective of this project is to design a data acquisition system through PC. PC based wireless data acquisition system will collects the data at predefined time intervals from different sensors for different physical measurements like temperature, light, Voltage variations, moisture and pressure etc. and that will be displayed on the PC through wireless communication.
1.4 CIRCUIT DESCRIPTION:
This section gives an overview of the whole circuitry and hardware involved in the project. In this project we are having two sections. One is transmitter section and other is PC section. Here in this project we are using three different sensors as inputs for the maximum data inputs such as
-Light dependent resistor
- Voltage detector
- Temperature sensor
As these all are made with analog in the name of data and the controller accepts only the data which is in digital form we are using another component for converting from analog data to the digital data and called as the analog to digital converter (ADC). So, now the output of the ADC is in digital and was made to send to the controller. The controller analysis the data according to the program written by the designer and forward to the encoder. Actually here the data in the sense the output of the sensors. The encoder plays one of the important roles in the project because security is the first preference. Any data while communicating, the security stands in a high priority so we need a device for which the data is to be encoded before communicating and the device is the encoder. The required data which is send by the controller was passed through the encoder where it encodes and again sends to the RF TX for the transmission purpose. RF TX receives the data which is sent by the encoder and releases the data into the space in the form of signals. On the other hand we have the RF RX part where the data acquisition part took places. For that we have one RF RX, the decoder, the controller and the PC which is serially interfaced to the controller. The signal which is received by the RF RX is forwarded to the decoder IC...
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