Lesson Notes By Weeks and Term v4 - SHS 3
Digital and Analogue System Design
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Digital and Analogue System Design
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Subject: Robotics
Class: SHS 3
Term: 2nd Term
Week: 17
Grade code: 3.2.1.LI.2
Strand code: 2
Sub-strand code: 1
Content standard code: 3.2.1.CS.1
Indicator code: 3.2.1.LI.2
Theme: Robot Design Methodologies
Subtheme: Digital and Analogue System Design
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Welcome, future engineers! Look around you. From the traffic lights that control the flow of cars in Accra, to the automatic water pump that fills your "polytank" at home, to the security system that protects a shop at night, our world is filled with smart systems. These systems make decisions based on information they receive. They take in *inputs* (like a sensor detecting low water) and produce an *output* (like turning on a pump). This lesson will teach you the fundamental skill of designing the "brain" behind such systems using combinational logic circuits. You will learn how to take a real-life problem, break it down into logical steps, and design a digital circuit that solves it.
a. Analogue vs. Digital Systems
First, let's understand the two main types of signals our systems can use. Analogue Signals: These are continuous signals that can have any value within a range. Think of the volume knob on an old radio – you can turn it to any position, not just fixed steps. The temperature throughout the day is another example; it changes smoothly. Digital Signals: These signals have only a limited number of discrete (separate) values. In digital electronics, we are mainly concerned with just two values: HIGH (represented by the number 1) and LOW (represented by the number 0). A light switch is digital: it is either ON (1) or OFF (0).
For this lesson, we will focus on Digital System Design because it is the foundation of computers, microcontrollers, and most modern robotic control systems. We will use the binary states 1 (ON/TRUE/HIGH) and 0 (OFF/FALSE/LOW) to make logical decisions. b. The Digital Design Process (Project-Based Approach)
Designing a combinational logic circuit involves a systematic, five-step process. A combinational circuit is one where the output depends *only* on the current inputs. It has no memory of past events.