Lecture_10 - Analogue to Digital conversion

# Lecture_10 - Analogue to Digital conversion - SEE215...

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Faculty of Science and Technology Lecture 10 Analogue to Digital conversion SEE215

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Analogue The universe is essentially an analogue environment. Quantities such as weight, pressure, temperature, force, pH, voltage, etc. can have continuous values. These were traditionally measure with instruments which likewise gave gave an analogue representation of the quantity being measured. One quantity is expressed as an other analogous quantity. We, digitise the value when we read the instrument & assign a value to the quantity.
Digital electronics Since the introduction of digital electronics, the electronics where signals are handled with digital signals of 0’s & 1’s, rather then analogue voltages, our instruments have changed in design. The instruments alleviate us from the chore of deciding what the reading is, by the electronics automatically converting the analogue signal to a digital signal & displaying the value. These instruments generally have a microcontroller and an Analogue to Digital Converter in them. We can build our own instruments with microcontrollers.

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Designing & building our own digital instrumentation. With the knowledge of microcontrollers and Analogue to Digital Converters (ADC’s), we have the ability to design and build control systems which are capable of controlling analogue & digital systems. You have already learnt some measurement techniques and principles in SEE216. ADC Analogue Voltage in Digital voltage 1001010010010
Analogue to Digital converters There are many methods of performing a Digital to Analogue Conversion. The ATmega128 employs a technique known as successive approximation. The conversion produces a 10 bit result and takes a finite time. There are 8 analogue signals, which can be connected to the ADC channels of PORTF. Only one channel can be converted at any one time. The ADC is controlled by I/O registers

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Analogue Digital Converter in AVR ATMEGA 128 has a 10 bit ADC with an eight input channel Multiplexer.
Analogue Circuitry Analogue PORT

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