Campus wireless broadcast Intelligent remote control system design and implementation (1)

Current campus radio system is moving in a digital, networked, intelligent direction.

According to market needs and prospects, production campus instructional radio device has a unique advantage. This article combines Intelligent remote control campus wireless broadcasting system that focuses on the wireless radio control system design and implementation.

1 new Intelligent remote control campus wireless broadcasting system introduction

Smart remote control campus wireless broadcasting system is a wireless communication, audio and digital technologies as one of the new campus radio broadcasting system.

Campus wireless broadcasting system using phone dialer send dual tone multi-frequency DTMF (Dual Tone Multi-Frequency) means of communication. Dual-tone multi-frequency is a reliable, proven communication technologies, which provide a higher rate of dial-up, and quickly replaced the traditional turntable telephone use dial pulse signalling. In recent years, the DTMF also applies to interactive control systems in which the language menu, language messages, telephone banking and ATM terminals, etc. DTMF on transmission circuit requirements are low, by ordinary telephone line you can receive and transmit signals transmission distance, and there are many models of universal dual audio components are available. Campus wireless broadcasting system using stereo wireless FM transmitter. In order to avoid addressing the control signal interference to broadcast audio signal, the left channel to broadcast audio signal, the right channel for the double-receivers-addressed the audio signal. Modulated RF signal through emitting into the space of electromagnetic wave is transmitted to the broadcast of the receiver. Receiver through the antenna to the RF signal, after demodulation get stereo two channel audio signal. Left channel broadcasting the audio signal sent to the amplifier amplify; right channel dual audio control signal sent to a dual-audio decoder decodes, get the corresponding binary control code. The control code into the receiver's single-chip, microcontroller-based machine settings, coding, open or close the receiver power amplifier section for fixed-point/partition control all relevant broadcast point FM receiver function. Smart remote control wireless broadcasting system block diagram shown in Figure 1. Figure 1 the left are the manual keystroke, telecommunications terminals, PC machine, mainly used for wireless radio system control functions. PC in addition to the control function, can also provide broadcast audio source to the system.

2 campus radio system control hardware design

Smart remote control campus wireless broadcasting system mainly includes FM transmitter, FM receiver, control systems, as well as the four major broadcast sources.

This article focuses on the wireless radio control system. This control system can be divided into the manual keystroke control, PC control, PC remote phone control three ways. The entire control system of key components for digital addressable coding machine, all kinds of control means final will go through addressing coding machine control entire wireless broadcasting system.

2.1 digital coding machine

The core of digital coding machine components for SCM AT89C52 and DTMF dispatcher 9200.

Manual press control, telephone, remote control and PC PC control, eventually will build on the encoding machine microprocessor controls the information sent by 9200. Different control method for the biggest difference is that through manual keystroke, remote communication terminals and PC these different methods and tools for the entire wireless broadcasting system control directive to the microcontroller. Coding machine hardware structure as shown in Figure 2.

Figure 2, 8870 as DTMF receiver chip, for receiving remote telephone DTMF signals.

7289 to set input keyboard and output display of serial interface chip, external manual press. According to the different control methods for the control code to a single-chip, microcontroller to a serial interface of the control code for DTMF send chip 9200. More than 9200 according to different code produces a corresponding dual audio signal, and then add this dual audio signal transmitter modulation after firing into the air, the propagation of electromagnetic waves by reaching the receiver.

2.2 manual control section

Manual control of parts of the core components of the circuit: sets the keyboard input and output displayed in a body of integrated chip ZLG7289A.

ZLG7289A with serial interface, 8-bit total drive at the vaginal digital tube, you tube can independent digital display control no hidden and properties such as flashes, and provide loop left/cycle right display instructions. ZLG7289A also can connect as many as 64 keys of the keyboard matrix, keyboard controller circuit containing to jitter.

Manual key, if key is pressed, the key value into the 7289 chip, then key 7289 to coding machine, single-chip MCU on the key value after it is processed, as the control code for encoding machine 9200.

This makes it possible to achieve through action press-directed or partition of addressable control. In radio broadcasting systems, broadcast point more cases can manually key-panel set more than one piece of each tablet 7289 7289, have your own piece of selected signal in order to select the MCU devices.

2.3 PC control section

[1] [2] [3]