Resistors are one of the most fundamental and widely used components in electronics. They play a crucial role in controlling the flow of current, voltage division, and signal conditioning. Understanding resistors and their properties is essential for any electronics enthusiast or engineer.

Project: Creating a Voltage Divider Circuit

In this project, we will create a simple voltage divider circuit using resistors. The objective is to divide a given input voltage into a desired output voltage using resistors of specific values.

To build this circuit, we will need the following components:

1. Arduino Uno - 1x
2. Breadboard - 1x
3. Jumper wires - as required
4. Resistors:
   • 1kΩ resistor - 1x
   • 2kΩ resistor - 1x

Examples:

Example 1: Calculating the Output Voltage

int Vin = 5; // Input voltage
int R1 = 1000; // Resistance of R1 (1kΩ)
int R2 = 2000; // Resistance of R2 (2kΩ)

void setup() {
  Serial.begin(9600);
}

void loop() {
  float Vout = (Vin * R2) / (R1 + R2); // Calculate the output voltage
  Serial.print("Output Voltage: ");
  Serial.print(Vout);
  Serial.println("V");
  delay(1000);
}

Explanation:

• We define the input voltage (Vin) as 5V and the resistance values (R1 and R2) as 1kΩ and 2kΩ, respectively.
• In the loop, we calculate the output voltage (Vout) using the voltage divider formula: Vout = (Vin * R2) / (R1 + R2).
• The calculated output voltage is then printed to the serial monitor.

Example 2: LED Brightness Control

int Vin = 5; // Input voltage
int R1 = 1000; // Resistance of R1 (1kΩ)
int R2 = 2000; // Resistance of R2 (2kΩ)
int ledPin = 9; // Pin connected to the LED

void setup() {
  pinMode(ledPin, OUTPUT);
}

void loop() {
  float Vout = (Vin * R2) / (R1 + R2); // Calculate the output voltage
  analogWrite(ledPin, Vout * 255 / Vin); // Control LED brightness using PWM
  delay(100);
}

Explanation:

• Similar to the previous example, we calculate the output voltage using the voltage divider formula.
• Instead of printing the output voltage, we use it to control the brightness of an LED connected to pin 9 using Pulse Width Modulation (PWM).
• The analogWrite function maps the calculated output voltage to the range of 0-255, which corresponds to the brightness levels of the LED.