Arduino Exercises ENR107

Arduino Overview

• Arduino UNO is a microcontroller board based on the ATmega328P.
• It features analog input pins (6) ranging from 0 to 5 volts and digital pins (14) for binary input/output (0 or 5 volts).
• The board supports PWM output across 6 pins, enabling varying pulse widths.

Software Development

• Software is developed on a general-purpose computer and uploaded to the Arduino control board.
• After uploading, the board can function independently for various applications.

Analog to Digital Conversion

• An A/D converter in Arduino transforms analog input into a 10-bit binary number.
• Voltage levels are mapped as follows: 0 volts = binary 0000000000 and decimal 0; 5 volts = binary 1111111111 and decimal 1023.

Sampling Rate

• The sampling rate for the ADC on Arduino is 9650 samples per second (Baud Rate).
• The maximum frequency of input analog signals is half the sampling rate, with other rates achievable through advanced programming.

PWM Waveform and Duty Cycle

• Duty cycle determines the proportion of time a PWM signal is high (on) versus low (off).
• Duty cycle percentages: 0% for binary 00000000 (Decimal 0) and 100% for binary 11111111 (Decimal 255).
• Average value of PWM can be calculated using the formula: Average Value = (5 × Tw) / T, where Tw is the time the signal is high.

Program Structure

• Standard program structure includes declarations, functions, and commands to execute specific tasks.
• Digital Reading: digitalRead(pin) allows reading values from specified digital pins.

Class Exercise Example

• Example exercise involves writing a program to sense a slide switch connected to +5. If active, an LED connected to pin 12 flashes periodically; otherwise, it remains off.

Circuit Layout and Color Codes

• Use bus lines for supply voltages; ensure a neat layout with horizontal or vertical connecting lines.
• Color code standards:
  • Positive supply voltage 1: RED
  • Ground: GREEN
  • Positive supply voltage 2: PINK
  • Negative supply voltage: BLACK
  • Input lines: BLUE
  • Output lines: PURPLE

Tinkercad Simulator

• Tinkercad provides a platform for simulating Arduino projects and behaviors.

Serial Communication

• Utilize analogRead(potPin) to measure voltage from a potentiometer, with returned values between 0 and 1023.
• Establish serial communication using Serial.begin(9600) and output the ADC result through Serial.println() functions.

Digital/Analog Conversion Calculations

• Conversion formula: Analog Value = (5 × Digital Value) / 1023.
• Output voltage correlates with digital values ranging from 0 to 1023, producing corresponding analog values.

Additional Exercises

• Exercise 4.2 involves reading a variable voltage output from a potentiometer connected to one analog pin on Arduino, with the digital value changing between 0 and 1023 as the voltage varies from 0 to 5 volts.