Lab Session 0: Microcontrollers simulation with Wokwi¶

Estimated time: 1.5h (1 session)

1. Launch an example¶

Access the Wokwi simulation environment via this link.
Select the ESP32 template.

Warning

Open the ESP32 template from Starter Templates, not from ESP-IDF Templates. The former is based on the Arduino IDE while the latter is based on the ESP-IDF environment that will not be used in the course.
Connect an LED to GPIO 21 with a resistor, as shown in the diagram (rotate - R and flip - P components if necessary).

Simulate the following sketch:

#define LED_PIN 21
#define BUTTON_PIN 35

void setup() {
    pinMode(LED_PIN, OUTPUT);
    pinMode(BUTTON_PIN, INPUT_PULLUP);
}

void loop() {
    digitalWrite(LED_PIN, HIGH);
    delay(500);
    digitalWrite(LED_PIN, LOW);
    delay(500);
}

Question

What is the purpose of the setup() function?
What is the purpose of the loop() function?
What does the #define do?
What does the pinMode() function do?
What does the digitalWrite() function do?
What does the delay() function do?

2. Control the LED state with a push button¶

Implement the circuit shown in the following diagram and simulate a program that:
- Turns the LED ON when the button is pressed.
- Turns the LED OFF when the button is not pressed.
Tip
- Use the function digitalRead() to get the status of the button.
- You may need to use the if...else condition.
Warning

When you place the button, don’t forget to deselect the bounce option to avoid bouncing issues.
Question
- What information is included in the diagram.json? Did it change with respect to the previous exercise?
- Can you do the exercise without using the if...else condition? How?

3. Additional exercises¶

3.1. Blink¶

Using the same circuit as in the previous exercise, write a script that Blinks the LED while the button is pushed.

Tip

You may need to use the millis() function.

3.2. Short press vs long press¶

Using the same circuit as in the previous exercise, write a script that does the following:
- Short press (< 500 ms): Toggle LED (if the LED is ON, turns it OFF, and viceversa).
- Long press (≥ 500 ms): Blink LED.
Tip

You may need to use the millis() function, and the if...else condition.