Week 8 Unusual Switch

Idea:

Since the problem is prompted to create a switch that should use the human body (but not the hands), I instantly come up with the idea to use photoresistor to control the circuit. As photoresistor reacts to the light intensity, basically you could use any body part to control the system as long as it cover/uncover the photoresistor.

Schematic:

It is a simple schematic, where I use A0 to read the LDR values and then programmed so that it affect how the built-in LED(D13) changes accordingly.

Code:

if (value <= lightThreshold) {
    digitalWrite(ledPin, HIGH);   // Dark → LED ON
  } else {
    digitalWrite(ledPin, LOW);    // Bright → LED OFF
  }

This is the part of the code where I control the light based on the A0 values.

The lightThreshold value is determined by experimenting and printing out the A0 value when cover/uncover the LDR.

Serial.print("Light level: ");
Serial.println(value);

 

Reflection:

It took me longer than expected to complete this as I am not familiar enough with working with the board. Nonetheless, it is a fun experience experimenting with both the hardware and the software at the same time. Future improvements would center around controlling other than built-in LEDs and improving the circuit design.