Based on typical curricula for **CSC3255** (often titled **Microprocessors and Embedded Systems** or **Computer Interfacing**), the electronic components focus on the bridge between software and physical hardware. The core objective is to understand how a CPU interacts with external circuitry. --- ## 1. Core Processing Unit At the center of any electronic system in this course is the **Microcontroller (MCU)** or **Microprocessor (MPU)**. | Component | Description | Role in CSC3255 | | :--- | :--- | :--- | | **Microcontroller** | An integrated circuit (IC) containing a CPU, memory, and I/O. | The "brain" that executes C/Assembly code to control hardware. | | **Crystal Oscillator** | A component that provides a stable clock signal. | Synchronizes the timing of instruction execution. | --- ## 2. Input/Output (I/O) Components These parts allow the system to sense the environment and act upon it. ### A. Input Components (Sensors & Switches) * **Push Buttons/Keypads:** Used for manual user input. Involves learning about **pull-up/pull-down resistors** and **debouncing**. * **Sensors:** * *Analog:* Potentiometers, Thermistors (require **ADC - Analog to Digital Converters**). * *Digital:* Ultrasonic sensors, PIR motion sensors. ### B. Output Components (Actuators & Displays) * **LEDs (Light Emitting Diodes):** Used for status indicators. Requires knowledge of current-limiting resistors. * **LCD/OLED Modules:** Character or graphical displays usually interfaced via **I2C** or **Parallel** ports. * **Motors:** DC Motors or Servos, often requiring a **Transistor** or **H-Bridge** for power amplification. --- ## 3. Communication Interfacing To connect these electronic parts, specific protocols and hardware pins are used: 1. **GPIO (General Purpose Input/Output):** Digital pins that can be set to High (1) or Low (0). 2. **UART (Universal Asynchronous Receiver-Transmitter):** For serial communication with a PC. 3. **I2C / SPI:** Bus protocols used to connect multiple sensors or memory chips using fewer wires. --- ## 4. Fundamental Circuit Components To protect the microprocessor and ensure signal integrity, these passive parts are essential: ```cpp // Example: Basic logic to toggle a GPIO pin connected to an LED #include #include int main(void) { DDRB |= (1 << PB0); // Set Pin B0 as Output while(1) { PORTB ^= (1 << PB0); // Toggle LED _delay_ms(500); } } ``` * **Resistors:** To limit current and prevent burning out LEDs or the MCU. * **Capacitors:** To smooth out power supply fluctuations (decoupling). * **Transistors (BJT/MOSFET):** Used as electronic switches to control high-power devices that the MCU cannot power directly. --- ## 5. Summary Table of Interfacing | Interface Type | Electronic Part Example | Data Type | | :--- | :--- | :--- | | **Digital In** | Tactile Switch | Discrete (0 or 1) | | **Digital Out** | Buzzer / LED | Discrete (On/Off) | | **Analog In** | Light Dependent Resistor (LDR) | Continuous Voltage (0V - 5V) | | **PWM Out** | Servo Motor | Pulse Width Modulation |