💡 Level 1 – Fundamentals

Project 1.4: "DC Motor Control"

🚀 Project 1.4 – DC Motor Control

🎯 What You’ll Learn

✅ Goal 1: Rotate a DC motor in both directions.
✅ Goal 2: Control motor speed with PWM.
✅ Goal 3: Drive two motors together for coordinated movement.

Key Ideas

Digital output: Control motor direction pins.
PWM: Adjust motor speed.
Loop: Repeat coordinated movement.

🧱 Blocks Glossary (used in this project)

Digital output: Set motor direction pins HIGH/LOW.
PWM: Control motor speed by duty cycle.
Loop (while True / for): Repeat actions.

🧰 What You Need

Part	How many?	Pin connection
D1 R32	1	USB cable
L298N Driver	1	IN1=Pin 2, IN2=Pin 4, ENA=Pin 5
TT Motor	2	Connected to L298N outputs
Wheels	2	Attached to motors

🔌 Wiring tip: Connect motor driver inputs to pins 2, 4, 5. Motors to L298N outputs.
📍 Pin map snapshot: Pin 2 = IN1, Pin 4 = IN2, Pin 5 = ENA (PWM).

✅ Before You Start

USB cable plugged in
Motors wired correctly to L298N
Test print shows:

print("Ready!")  # Confirm serial is working

🎮 Microprojects (5 Mini Missions)

🎮 Microproject 1.4.1 – The motor rotates in one direction

Goal: Spin motor clockwise.
Blocks used: Digital output
Block sequence:

IN1 HIGH, IN2 LOW → Motor forward

MicroPython Code:

import machine, time                         # Importa librerías
pin2 = machine.Pin(2, machine.Pin.OUT)       # IN1 salida
pin4 = machine.Pin(4, machine.Pin.OUT)       # IN2 salida

pin2.value(1)                                # IN1 HIGH
print("IN1 HIGH")                            # Serial: IN1 encendido
pin4.value(0)                                # IN2 LOW
print("IN2 LOW")                             # Serial: IN2 apagado

time.sleep(3)                                # Motor gira 3 segundos

🎮 Microproject 1.4.2 – The motor rotates in the opposite direction

Goal: Spin motor counterclockwise.
Blocks used: Digital output
Block sequence:

IN1 LOW, IN2 HIGH → Motor reverse

MicroPython Code:

import machine, time
pin2 = machine.Pin(2, machine.Pin.OUT)       # IN1 salida
pin4 = machine.Pin(4, machine.Pin.OUT)       # IN2 salida

pin2.value(0)                                # IN1 LOW
print("IN1 LOW")                             # Serial: IN1 apagado
pin4.value(1)                                # IN2 HIGH
print("IN2 HIGH")                            # Serial: IN2 encendido

time.sleep(3)                                # Motor gira 3 segundos en reversa

🎮 Microproject 1.4.3 – Speed control with PWM

Goal: Control motor speed.
Blocks used: PWM, Digital output
Block sequence:

Setup ENA pin as PWM
Adjust duty cycle for speed

MicroPython Code:

import machine, time
pin2 = machine.Pin(2, machine.Pin.OUT)       # IN1 salida
pin4 = machine.Pin(4, machine.Pin.OUT)       # IN2 salida
pwm5 = machine.PWM(machine.Pin(5))           # ENA PWM en pin 5

pin2.value(1); pin4.value(0)                 # Dirección: adelante
print("Direction: Forward")                  # Serial: dirección adelante

pwm5.freq(2000)                              # Frecuencia PWM
print("PWM frequency set to 2000Hz")         # Serial: frecuencia configurada

pwm5.duty(512)                               # Velocidad media (duty 50%)
print("Motor speed: 50% duty")               # Serial: velocidad media

time.sleep(3)                                # Motor corre 3 segundos

🎮 Microproject 1.4.4 – Two simultaneous engines

Goal: Run two motors at once.
Blocks used: Digital output, PWM
Block sequence:

Setup IN1/IN2 for motor A, IN3/IN4 for motor B
Both forward

MicroPython Code:

import machine, time
# Motor A
pin2 = machine.Pin(2, machine.Pin.OUT)       # IN1 salida
pin4 = machine.Pin(4, machine.Pin.OUT)       # IN2 salida
pwm5 = machine.PWM(machine.Pin(5))           # ENA PWM

# Motor B
pin12 = machine.Pin(12, machine.Pin.OUT)     # IN3 salida
pin13 = machine.Pin(13, machine.Pin.OUT)     # IN4 salida
pwm14 = machine.PWM(machine.Pin(14))         # ENB PWM

pin2.value(1); pin4.value(0)                 # Motor A adelante
print("Motor A forward")
pin12.value(1); pin13.value(0)               # Motor B adelante
print("Motor B forward")

pwm5.freq(2000); pwm5.duty(512)              # Motor A velocidad media
print("Motor A speed 50%")
pwm14.freq(2000); pwm14.duty(512)            # Motor B velocidad media
print("Motor B speed 50%")

time.sleep(3)                                # Ambos motores giran 3 segundos

🎮 Microproject 1.4.5 – Coordinated forward/backward movement

Goal: Drive both motors forward then backward.
Blocks used: Digital output, PWM, Loop
Block sequence:

Both forward → Delay 3s
Both backward → Delay 3s
Repeat

MicroPython Code:

import machine, time
# Motor A
pin2 = machine.Pin(2, machine.Pin.OUT)
pin4 = machine.Pin(4, machine.Pin.OUT)
pwm5 = machine.PWM(machine.Pin(5))

# Motor B
pin12 = machine.Pin(12, machine.Pin.OUT)
pin13 = machine.Pin(13, machine.Pin.OUT)
pwm14 = machine.PWM(machine.Pin(14))

pwm5.freq(2000); pwm14.freq(2000)            # Configura frecuencia PWM
pwm5.duty(512); pwm14.duty(512)              # Velocidad media

while True:                                  # Bucle infinito
    pin2.value(1); pin4.value(0)             # Motor A adelante
    pin12.value(1); pin13.value(0)           # Motor B adelante
    print("Both motors forward")             # Serial: ambos adelante
    time.sleep(3)

    pin2.value(0); pin4.value(1)             # Motor A atrás
    pin12.value(0); pin13.value(1)           # Motor B atrás
    print("Both motors backward")            # Serial: ambos atrás
    time.sleep(3)

✨ Main Project – DC Motor Control

🔧 Blocks Steps (with glossary)

Digital output: Control motor direction pins (IN1, IN2, IN3, IN4).
PWM: Control motor speed (ENA, ENB).
Loop: Repeat coordinated forward/backward movement.

Block sequence:

Setup pins for motor driver (IN1, IN2, ENA, IN3, IN4, ENB).
Run forward sequence.
Run backward sequence.
Repeat forever.

🐍 MicroPython Code (mirroring blocks)

# Project 1.4 – DC Motor Control

import machine, time                               # Importa librerías para pines y tiempo

# Motor A
pin2 = machine.Pin(2, machine.Pin.OUT)             # IN1 salida
pin4 = machine.Pin(4, machine.Pin.OUT)             # IN2 salida
pwm5 = machine.PWM(machine.Pin(5))                 # ENA PWM en pin 5

# Motor B
pin12 = machine.Pin(12, machine.Pin.OUT)           # IN3 salida
pin13 = machine.Pin(13, machine.Pin.OUT)           # IN4 salida
pwm14 = machine.PWM(machine.Pin(14))               # ENB PWM en pin 14

# Configuración inicial de PWM
pwm5.freq(2000)                                    # Frecuencia PWM motor A
print("Motor A PWM frequency set to 2000Hz")       # Serial: frecuencia motor A
pwm14.freq(2000)                                   # Frecuencia PWM motor B
print("Motor B PWM frequency set to 2000Hz")       # Serial: frecuencia motor B

pwm5.duty(512)                                     # Duty 50% motor A
print("Motor A speed set to 50% duty")             # Serial: velocidad motor A
pwm14.duty(512)                                    # Duty 50% motor B
print("Motor B speed set to 50% duty")             # Serial: velocidad motor B

while True:                                        # Bucle infinito
    # Ambos motores adelante
    pin2.value(1); pin4.value(0)                   # Motor A adelante
    pin12.value(1); pin13.value(0)                 # Motor B adelante
    print("Both motors forward")                   # Serial: ambos adelante
    time.sleep(3)                                  # Espera 3 segundos

    # Ambos motores atrás
    pin2.value(0); pin4.value(1)                   # Motor A atrás
    pin12.value(0); pin13.value(1)                 # Motor B atrás
    print("Both motors backward")                  # Serial: ambos atrás
    time.sleep(3)                                  # Espera 3 segundos

📖 External Explanation

What it teaches: How to control DC motors with direction and speed.
Why it works: Digital outputs set motor direction, PWM adjusts speed, and loops repeat actions.
Key concept: Direction + speed + repetition = motor control system.

✨ Story Time

Imagine your robot is a small car. With these blocks, you can make it drive forward, reverse, and even adjust its speed like a real vehicle.

🕵️ Debugging (2 Common Problems)

🐞 Debugging 1.4.A – Motor does not rotate (reverse polarity)

Problem: Motor stays still.
Clues: Wrong wiring polarity.
Broken code/wiring:

pin2.value(0); pin4.value(0)   # Ambos LOW, motor no recibe dirección

Fixed code:

pin2.value(1); pin4.value(0)   # Dirección correcta: motor adelante

Why it works: One pin HIGH and the other LOW sets rotation.
Avoid next time: Always check polarity and wiring.

🐞 Debugging 1.4.B – Inconsistent speed

Problem: Motor speed changes unexpectedly.
Clues: PWM duty not set or too low.
Broken code:

pwm5.duty(10)   # Duty demasiado bajo, motor apenas gira

Fixed code:

pwm5.duty(512)  # Duty medio, motor estable

Why it works: Proper duty cycle ensures consistent speed.
Avoid next time: Use values between 256–768 for stable speeds.

✅ Final Checklist

Motor rotated forward and backward.
Speed controlled with PWM.
Two motors ran simultaneously.
Coordinated forward/backward movement worked.

📚 Extras

🧠 Student tip: Try different duty cycles to simulate acceleration.
🧑‍🏫 Instructor tip: Verify motor driver wiring before running.
📖 Glossary: Digital output, PWM, Duty cycle.
💡 Mini tips: Always test one motor before connecting two.