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Showing posts from January, 2014

8x8 LED Matrix

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Introduction This product is a serially driven 8x8 LED Matrix kit powered by MAX7219. It only needs three data lines and two power lines. The 8x8 LED Matrix is easy to use and compatible with Arduino, and its LED brightness adjustment can be implemented in software. 8x8 LED Matrix kit has many applications in real life, such as various types of electronic display panels. If the LED matrix is not driven by any peripherals, it’ll waste the interface of devices, and the LED brightness will be impaired due to insufficient power, so that we cannot get ideal display effect. The LED matrix can be driven in two ways: parallel or serial. We usually drive it in the serial manner in order to save interface. The serial-driven LED matrix actually dynamically displays the LEDs, i.e., displays the LEDs row-by-row or column-by-column. The persistence of vision for humans is about 0.1s, so as long as we can serially display all 8 rows/columns within 0.1s, we’ll see a complete characte

AM Radio using 555 timer IC

Touch Switch using IC 555

555 TIMER

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Introduction: It is a IC chip used in vareity of timer,pulse generation and oscillator application. It is one of the cheapest and most rugged chip in the market. It is used to provide accurate and highly stable time delays or an oscillation. It is in widespread use due it's ease of use,low price and stability. It was estimated that 1 billion units are manufactured every year. Depending upon the manufacture the standard 555 package include 25 transistors,2 diodes and 15 resistors on a silicon chip installed in 8-pin mini dual-in-line package(DIP-8). The circuitary inside the chip takes about 10MA even if the o/p is not driving the load i.e it is not suitable for battery operation if the chip is to be powered all the time. This timer bascially operates in one of the two modes either as an Monostable(one shot)or an astable. The chip producing output frequency 1 cycle per second i.e 1HZ is called Oscillator.but below 1HZ is called Timer. The specification of 555 timer is