Draft for Design and Implementation FSK Remote Control System Using ATmiga16 Microcontroller A project is just a draft so; many mistakes and grammar errors will be there. Abdullah Abdullah A. Mohamed; Khalaf Al-sabaawi Communication Department Collages of Electronics Engineering - Mosul university-Iraq
[email protected];
[email protected]
Abstract The meaning of remote control is the controlling of the equipment or devices without any physical connections and it provide access for the devices that cannot be reached easily. There are many approaches for doing remote control one of them is our project which include FSK techniques.
1
Chapter 1 Introduction •
Many of practical applications (for example, the machines in factory , missiles tracking ) require a way to communicate electronically with a central office , so that measured data can be reported back to the central office and new tariffs can be set in the remote site and feedback the necessary orders to the controlled device through the remote controlling unit system . This controlling order is usually digital codes, in digital signaling we seek to send one of two logic states. Traditionally we label these states as logic “1” or logic “0”. In a digital circuit, voltages such as 5v for logic "1" and 0v for logic "0" usually represent these states. Frequency shift keying (FSK) is one of the most popular methods of representing digital data. FSK is also known as frequency shift modulation and frequency shift signaling. FSk is data signal converted into specific frequency or tone in order to transmit it over wire ,optical fiber or wireless media to a destination point , and it has many types such as
1. 1_ Binary Frequency Shift Keying (BFSK) 2. 2_ Multiple Frequency Shift Keying (MFSK) 3. 3_Audio frequency-shift keying (AFSK) 4. 4_Minimum frequency-shift keying or minimum-shift keying (MSK) 5.
5_Gaussin Minimum Shift Keying(GMSK)
The simplest FSK is binary FSK (BFSK). BFSK literally implies using a pair of discrete frequencies to transmit binary (0s and 1s) information. With this scheme, the "1" is called the mark frequency and the "0" is called the space frequency
2
1.1 Motivation We choose this project because of most of the modern technique today use the remote control unite where it provide a good facilities for human.
1.2 Aim of the project This project aim to build wireless control unit for several devices ( 8 switches turn on/off ) , and here we used the technique of frequency shift keying (FSK)
Chapter2 Background The trend in wireless system is overwhelmingly towards digital modulation for a variety of reasons. An obvious reason is that if we want to transmit digital information (e.g., digital code) we need to employ digital modulation. However, even for analog signals like voice, digital modulation is very attractive because in the digital domain we can employ coding for the purposes of data compression, encryption, and error correction. These results in a system that makes much more efficient use of bandwidth and power and can provide a wider array of services for our customers. The “real world” is analog. As such we implement digital modulation using analog systems. For the same reasons that FM is superior to AM for analog radio communication, most digital schemes employ frequency- or phase-shift techniques.
3
2.1 Digital Signals In digital signaling, we seek to send one of two logic states. Traditionally we label these states as logic “1” or logic “0”. In a digital circuit these states are usually represented by voltages such as 5 V for logic 1 and 0 V for logic 0. In RF it is almost always more convenient to have a symmetric representation, so we will typically use, say 1 V for logic 1 and –1 V for logic 0. Although we ultimately are interested is communicating a stream of discrete bits, we must implement this with continuous-time signals. Say we wish to send the bit pattern 010… with one bit being sent every Tb seconds. Tb is called the bit period. The bit rate, or number of bits per second, is Rb= 1/ Tb .We communicate a bit pattern by forming a continuous-time function m (t) where m (t) = -1 for 0 ≤ t < Tb m (t) = +1 for Tb ≤ t > 16)>>8; if(DataCode== _DataCode) { for(temp=0;temp
