Question

const int LED11 = 11;
const int SW12 = 12;
int sw_in;

void setup() {
Serial.begin(9600);
pinMode(LED11, OUTPUT);
pinMode(SW12, INPUT_PULLUP);
}

void loop() {
sw_in = digitalRead(SW12);
if (sw_in == LOW) {
digitalWrite(LED11, HIGH);
}
else {
digitalWrite(LED11, LOW);
}


Serial.print(“Switch State: ”);
Serial.print(sw_in);
Serial.print(“ | LED State: ”);
Serial.println(digitalRead(LED11));
delay(100);
}

Answer 1

Your Arduino code looks mostly fine; it reads the state of a switch and controls an LED based on that state, while also printing the states to the Serial Monitor. However, there's a small issue in the code related to the use of typographic quotes, which can cause a compilation error. Make sure to replace the curly quotes with straight quotes. Here’s a corrected version of your code:

```cpp
const int LED11 = 11;
const int SW12 = 12;
int sw_in;

void setup() {
Serial.begin(9600);
pinMode(LED11, OUTPUT);
pinMode(SW12, INPUT_PULLUP);
}

void loop() {
sw_in = digitalRead(SW12);
if (sw_in == LOW) {
digitalWrite(LED11, HIGH);
} else {
digitalWrite(LED11, LOW);
}

Serial.print("Switch State: ");
Serial.print(sw_in);
Serial.print(" | LED State: ");
Serial.println(digitalRead(LED11));
delay(100);
}
```

### Key Components of the Code:
1. **Constants Definition**: The pins for the LED and switch are defined at the beginning using `const int`.
2. **Setup Function**: Initializes the Serial communication at 9600 baud and sets the pin modes for the LED (output) and the switch (input with an internal pull-up resistor).
3. **Loop Function**:
- Reads the state of the switch.
- If the switch is pressed (`LOW` due to the pull-up configuration), the LED is turned on; otherwise, it is turned off.
- The states of both the switch and the LED are printed to the Serial Monitor.
- A small delay of 100 milliseconds is included to prevent flooding the serial output.

### Note:
- Make sure that the connections are correct: The LED should be connected to pin 11 (with a resistor in series), and the switch should connect pin 12 to ground when pressed.
- After uploading the code to your Arduino, open the Serial Monitor to observe the output reflecting the switch and LED states.