Input Devices

We performed several simulations using Wokwi, an online electronics and embedded systems simulator that allows you to develop and test projects with microcontrollers such as Arduino, ESP32, STM32, and Raspberry Pi Pico, among others. Below are some exercises we developed with Instructor Ulises.

Exercise 1 using Wokwi simulator

This is the code I used:

from machine import Pin
from time import sleep
				
print("Hello, Fab Academy 2025!")
				
pinLed = Pin(3, Pin.OUT)
				
while True:
	#pinled.toggle()
	pinLed.value(0)
	print("Apagado")
	sleep(1.0)
	pinLed.value(1)
	print("Encendido")
	sleep(1.0)												

Exercise 2

This is the code I used:

											
from machine import Pin
from time import sleep

print("Hello, Fab Academy 2025!")

pinLed = Pin(3, Pin.OUT)
pinBut = Pin(26, Pin.IN)

while True:
    print(pinBut.value())
   	pinLed.value(pinBut.value())
    sleep(0.5)

Exercise 3:

This is the code I used:

#include <Wire.h>
#include <MPU6050.h>
													
MPU6050 mpu;
													
// Variables para inclinación
float anguloX, anguloY;
unsigned long tiempoPrev;
float dt;
													
void setup() {
  Serial.begin(115200);
  Wire.begin();
  mpu.initialize();
													  
  if (mpu.testConnection()) {
  Serial.println("MPU6050 conectado correctamente");
  } else {
  Serial.println("Error al conectar MPU6050");
  while (1);
  }
													  
  // Calibración inicial (dejar el sensor quieto 3 segundos)
  Serial.println("Calibrando... No muevas el sensor");
  delay(3000);
  tiempoPrev = millis();
  }
													
void loop() {
  // Leer datos del giroscopio y acelerómetro
  int16_t ax, ay, az, gx, gy, gz;
  mpu.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);
													  
  // Calcular intervalos de tiempo
  dt = (millis() - tiempoPrev) / 1000.0;
  tiempoPrev = millis();
													  
  // Convertir a valores útiles
  float aceleracionX = ax / 16384.0; // Escala ±2g
  float aceleracionY = ay / 16384.0;
  float giroX = gx / 131.0;         // Escala ±250°/s
  float giroY = gy / 131.0;
													  
  // Calcular ángulos de inclinación (filtro complementario)
  anguloX = 0.98 * (anguloX + giroX * dt) + 0.02 * atan2(aceleracionY, sqrt(aceleracionX * aceleracionX + az / 16384.0 * az / 16384.0)) * 180 / PI;
  anguloY = 0.98 * (anguloY + giroY * dt) + 0.02 * atan2(aceleracionX, sqrt(aceleracionY * aceleracionY + az / 16384.0 * az / 16384.0)) * 180 / PI;
													  
  // Mostrar resultados en Serial
  Serial.print("Inclinación X: "); Serial.print(anguloX); Serial.print("° | ");
  Serial.print("Y: "); Serial.print(anguloY); Serial.println("°");
													  
  Serial.print("Giro X: "); Serial.print(giroX); Serial.print("°/s | ");
  Serial.print("Y: "); Serial.print(giroY); Serial.println("°/s");
													  
  Serial.println("---------------------");
  delay(200); // Ajusta este delay para mayor/menor frecuencia de lectura
}
												

Sensor Measurement with DHT11

DHT11 Sensor Specifications

• Temperature range: 0°C to 50°C ±2°C
• Humidity range: 20% to 90% RH ±5%
• Operating voltage: 3.3V to 5.5V
• Digital output signal
• Sampling rate: 1 reading every second
• Low power consumption
• 4-pin single row package
• Compact size and easy to use

Objective

Measure temperature and humidity using the DHT11 sensor connected to a microcontroller board (XIAO ESP32-C3).

Materials

• DHT11 Sensor
• XIAO ESP32-C3 or Arduino Uno
• USB cable
• Arduino IDE

Connections

Arduino Code

// Bit‑banging DHT11 without external library
const int DHpin = 2;  // Use GPIO2 (adjust if needed)
byte dat[5];          // [hum_int, hum_dec, temp_int, temp_dec, checksum]

void setup() {
  Serial.begin(115200);
  pinMode(DHpin, OUTPUT);
  digitalWrite(DHpin, HIGH);  // Bus idle high
}

byte read_data() {
  byte result = 0;
  for (int i = 0; i < 8; i++) {
    while (digitalRead(DHpin) == LOW);
    delayMicroseconds(30);
    if (digitalRead(DHpin) == HIGH)
      result |= (1 << (7 - i));  // MSB first
    while (digitalRead(DHpin) == HIGH);
  }
  return result;
}

void start_test() {
  digitalWrite(DHpin, LOW);
  delay(20);                // >18ms for DHT11
  digitalWrite(DHpin, HIGH);
  delayMicroseconds(40);
  
  pinMode(DHpin, INPUT);
  while (digitalRead(DHpin) == HIGH);
  delayMicroseconds(80);
  
  for (int i = 0; i < 5; i++) 
    dat[i] = read_data();
  
  pinMode(DHpin, OUTPUT);
  digitalWrite(DHpin, HIGH);
}

void loop() {
  start_test();
  
  byte checksum = dat[0] + dat[1] + dat[2] + dat[3];
  if (dat[4] != checksum) {
    Serial.println("Error de checksum!");
    delay(2000);
    return;
  }
  
  Serial.print("Humedad: ");
  Serial.print(dat[0]);
  Serial.print(".");
  Serial.print(dat[1]);
  Serial.println("%");
  
  Serial.print("Temperatura: ");
  Serial.print(dat[2]);
  Serial.print(".");
  Serial.print(dat[3]);
  Serial.println("°C");
  
  delay(2000);
}
  

Results

Use the Serial Monitor to view live data:

• Temperature in °C
• Humidity in %

Impact Sensor KY-031

KY-031 Impact Sensor Specifications

• Operating voltage: 3.3V to 5V
• Digital output
• Output type: High when idle, Low when impact detected
• Built-in LM393 voltage comparator
• Adjustable sensitivity via onboard potentiometer
• Mounting hole for easy installation
• 3-pin interface: VCC, GND, and D0 (signal)
• Compact and easy to integrate into projects

Objective

Measure the digital signals generated by the Impact Sensor KY-031 when it detects a shock or vibration, and display the data on the serial monitor or Serial Plotter.

Required Materials

• KY-031 Impact Sensor Module
• ESP32-C3 XIAO
• USB cable for uploading code
• Computer with Arduino IDE installed

Connections

This is the code I used:

const int Shock = 2;  // KY-031 en GPIO2

int val;              // Variable para leer el sensor

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

void loop() {
  val = digitalRead(Shock);
  
  if(val == HIGH) {
    Serial.println("GOLPE REAL");  
    delay(100); 
  }
  else {
    Serial.println("sin golpe");  
    delay(100); 
  }
}