Circuit Documentation

Summary

The circuit is designed to function as a scoreboard system, utilizing two photocells (LDRs) to detect scores for two teams. When a score is detected, an LED for the corresponding team is illuminated. The Arduino UNO microcontroller reads analog inputs from the photocells and controls the LEDs based on the sensor values. The circuit includes resistors for current limiting and voltage division purposes.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• It has 14 digital input/output pins, 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button.

Photocell (LDR)

• A light-dependent resistor whose resistance changes with light intensity
• Used to detect score events in the circuit

Resistor (200 Ohms)

• A passive two-terminal electrical component that implements electrical resistance as a circuit element
• Used for current limiting and voltage division

LED: Two Pin (red)

• A red light-emitting diode
• Used to indicate a score event for a team

Wiring Details

Arduino UNO

• 5V pin is connected to the pin 1 of both Photocells (LDR)
• GND pin is connected to one side (pin1) of each 200 Ohm Resistor
• A0 pin is connected to the junction between pin 0 of Photocell 1 and pin2 of a 200 Ohm Resistor
• A1 pin is connected to the junction between pin 0 of Photocell 2 and pin2 of another 200 Ohm Resistor
• D13 pin is connected to the anode of the red LED
• GND pin is also connected to the cathode of the red LED through a 200 Ohm Resistor

Photocell (LDR)

• One side (pin 0) is connected to an analog input on the Arduino UNO (either A0 or A1)
• The other side (pin 1) is connected to the 5V supply on the Arduino UNO

Resistor (200 Ohms)

• One side (pin1) is connected to the GND on the Arduino UNO
• The other side (pin2) is connected to either a Photocell (LDR) or the cathode of the red LED

LED: Two Pin (red)

• Anode is connected to the D13 on the Arduino UNO
• Cathode is connected to GND on the Arduino UNO through a 200 Ohm Resistor

Documented Code

/*
  Scoreboard Project

  This code reads analog inputs from two photocells (LDRs) connected to pins A0
  and A1. If the analog value of either photocell is below a threshold, it
  indicates a score by turning on an LED connected to pin D13 for team 1 or
  pin D12 for team 2. Otherwise, it turns off the respective LED and prints the
  sensor values to the Serial Monitor.
*/

// Pin definitions
const int photocellPin1 = A0;  // Photocell for team 1 connected to A0
const int photocellPin2 = A1;  // Photocell for team 2 connected to A1
const int ledPin1 = 13;        // LED for team 1 connected to D13
const int ledPin2 = 12;        // LED for team 2 connected to D12

// Threshold for detecting a score
const int threshold = 10;

void setup() {
  // Initialize serial communication at 9600 bits per second
  Serial.begin(9600);
  // Initialize the LED pins as outputs
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
}

void loop() {
  // Read the input on analog pins A0 and A1
  int sensorValue1 = analogRead(photocellPin1);
  int sensorValue2 = analogRead(photocellPin2);
  // Check if the sensor value for team 1 is below the threshold
  if (sensorValue1 < threshold) {
    Serial.println("Team 1 Scores!");
    digitalWrite(ledPin1, HIGH);  // Turn the LED on for team 1
    delay(1000);  // Delay for 1 second
  } else {
    digitalWrite(ledPin1, LOW);  // Turn the LED off for team 1
    Serial.print("Team 1: ");
    Serial.println(sensorValue1);  // Print the sensor value for team 1
  }
  // Check if the sensor value for team 2 is below the threshold
  if (sensorValue2 < threshold) {
    Serial.println("Team 2 Scores!");
    digitalWrite(ledPin2, HIGH);  // Turn the LED on for team 2
    delay(1000);  // Delay for 1 second
  } else {
    digitalWrite(ledPin2, LOW);  // Turn the LED off for team 2
    Serial.print("Team 2: ");
    Serial.println(sensorValue2);  // Print the sensor value for team 2
  }
  delay(1);  // Delay in between reads for stability
}

Filename: Scoreboard sketch 20241008.ino