Web-Based programmable logic control (PLC)

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Today there are very rapid development of technology and progress, these developments require humans to continue to innovate to create tools that can help in performing daily activities.

Many activities to do outside the home who sometimes have to leave home until the days and – days. Usually we always turn out the lights when leaving the house empty. This could cause the waste of electrical energy consumption for lighting during the day alive, and will also lead to vulnerability to theft because the house is seen in a state of no activity. To overcome this, the authors sought to create control systems electrical installations are cheap and easy to apply.
This application which will manage all electrical systems to manipulate the situation as if uninhabited, except that this application will replace our work in the light turn on and off every day. Therefore, the authors tried to examine and make the “Applications Web-Based Control Electrical Equipment OpenWRT”.
OpenWRT is an operating system (actually more properly called Firmware) that can be installed (more precisely planted / in-embedded) on a wireless radio device. OpenWRT is to replace the function of a PC is usually used in the application of programmable logic control (PLC), as an OpenWRT operating system can be installed with various applications such as web server and PHP. With this capability makes the “Applications Web-Based Control Electrical Equipment OpenWRT” is very flexible and low cost. Another capability of this application is able to control your home from anywhere are, as long as it can be connected to the internet.

Author : puguh

Copyright: Puguhwah@yahoo.com



Digital Volume Control

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This digital volume control has no pot to wear out and introduces almost no noise in the circuit. Instead, the volume is controlled by pressing UP and DOWN buttons. This simple circuit would be a great touch to any home audio project.


Capacitor [C1]  = 0.1uF
IC [U1]              = DS1669
Switch [S1, S2] = PushButton

simple FSK Demodulator

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Here is application of the 565 PLL is as a FSK demodulator. In the 565 PLL the frequency shift is usually accomplished by driving a VCO with the binary data signal so that the two resulting frequencies corre­spond to the logic 0 and logic 1 states of the binary data signal. The frequencies corresponding to logic 1 and logic 0 states are commonly called the mark and space frequencies. Several standards are used to set the mark and space frequencies.

The demodulator receives a signal at one of the two distinct carrier frequencies, 1,270 Hz or 1,070 Hz representing the RS-232 C logic levels of mark (- 5 V) or space (+ 14 V), respectively. Capacitance coupling is used at the input to remove a dc level.

Radio Control/RS-232 over FM Radio

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Here is Decoder and Encoder for FM transmitter and FM radio Receiver, This circuit is a solution for transmit data in long distance.

The RF Solutions RF600E, & RF600D are easy to use encoder and decoder I/C’s. They have been designed to achieve the maximum possible range from any radio / Infra Red transmitter receiver set.
Unlike other encoder /decoder devices the RF600E/600D provide an unprecedented level of security which prevents copying or grabbing whist also obtaining optimum range from the transmitter and receiver.
The devices are very easy to use and can be inserted directly into a circuit. The RF600D has an easy learn feature enabling it to learn up to 7 unique RF600E encoder devices in standalone mode or up to 48 encoder devices when used in conjunction with an external EEPROM. These devices enable a simple but secure remote telemetry application whilst obtaining the maximum range from the radio set.

The RF600D has a serial data output. This outputs the serial number, button and battery status of the transmitter encoder (RF600E) it has successfully received. It also gives an indication of which inputs of the encoder have been activated and the status of the encoder battery. This data may be fed directly to a microcontroller or RS232 type driver circuit which may then be fed directly to a PC serial port. (An RS232 serial data output is provided on SA123 & RFEVAL2).
Serial data is output continually whilst data is being received from the RF600E transmitter. i.e. this output is valid regardless of whether the RF600E encoder has been learnt to the RF600D decoder or not. If the user requires the serial number of pre-learnt RF600E encoders only, then the serial output should be configured only to output data when one of the digital outputs from the RF600D is asserted. (Digital outputs from the RF600E will only activate when a RF600E encoder has been pre-learnt.)

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