TEB2053 Embedded Systems - Week 8

• This module covers the fundamentals of Analogue-to-Digital Converters (ADC), including:

  1. ADC Basics – Converts analogue signals into digital values.

  2. Types of ADCs – SAR, Delta-Sigma, Dual Slope, Pipelined, and Flash ADCs.

  3. Arduino-Based ADC – ATmega328P’s 10-bit SAR ADC, input channels, and voltage reference.

  4. ADC Configuration – Setting ADMUX, ADCSRA, and ADCSRB registers for operation.

  5. Resolution & Calculation – Using formulas to determine digital output from input voltage.

  6. Arduino Programming – Configuring and reading ADC values in Arduino.

​Pulse Width Modulation (PWM) is a technique used to control power delivery by varying the duty cycle of a digital signal. It is commonly used in motor control, LED dimming, and signal generation.

Key Concepts:

1. Duty Cycle (%) – The percentage of time the signal is HIGH in one cycle.

   • Formula: Duty Cycle (%) = (TON / T) × 100

   • Higher duty cycle = More power delivered; Lower duty cycle = Less power.

2. Frequency (Hz) – The number of PWM cycles per second.

   • Formula: PWM Frequency = 1 / T (where T = total period)

   • Higher frequency reduces flicker but affects resolution.

​Function – Converts analogue signals into digital values for microcontroller processing.

• Resolution – Defined by bit depth (N-bit ADC), determining precision (e.g., 10-bit ADC gives values from 0 to 1023).

• Types – Includes SAR, Delta-Sigma, Flash, Dual Slope, and Pipelined ADCs, each with different speed and accuracy trade-offs.

• Microcontroller ADC (ATmega328P) – Uses a 10-bit SAR ADC with 6 input channels, controlled via ADMUX, ADCSRA, and ADCSRB registers.

• Applications – Used in sensor data acquisition, signal processing, and real-world monitoring like temperature, pressure, and motion detection.