9. Input devices¶

Group assignment:¶

• Probe an input device(s)'s analog and digital signals

• Document your work on the group work page and reflect on your individual page what you learned

To see our group assignment click here

Individual assignment:¶

• add a sensor to a microcontroller board that you have designed and read it.

My Custom PCB¶

The sensor is connected to the custom PCB I designed during Week 06 — Electronics Design, based on an ESP32-WROOM microcontroller.

Final Project Development: Smart Mode Management via LDR Sensor¶

This section details the development and implementation of the LDR (Light Dependent Resistor) sensor within the final project architecture.

Operational Modes¶

Code¶

The following code reads the LDR analog value and switches between the two modes:

#define LDR_PIN 34        // Analog pin connected to LDR
#define THRESHOLD 2000    // Adjust based on your environment

void setup() {
  Serial.begin(115200);
  pinMode(LDR_PIN, INPUT);
}

void loop() {
  int ldrValue = analogRead(LDR_PIN);
  Serial.print("LDR Value: ");
  Serial.println(ldrValue);

  if (ldrValue < THRESHOLD) {
    // Room light is OFF → Night light mode
    Serial.println("Mode:  Night Light");
    // Add your night light logic here
  } else {
    // Room light is ON → Visitor mode
    Serial.println("Mode:  Visitor");
    // Add your visitor mode logic here
  }

  delay(500);
}

Serial Monitor — Demo¶

The video below shows the Serial Monitor output as the light condition changes in real time:

Wiring Diagram¶

Results & Observations¶

• The LDR successfully detects the light state of the room.
• The ESP32 switches between Night Light and Visitor modes in real time.
• The Serial Monitor confirms the readings and mode transitions.

Files¶