Project Overview

This project introduces basic digital output control by making an LED blink. Students will learn about GPIO pins and simple timing in MicroPython.

Educational Goals

• Introduce basic electronics concepts (circuits, LEDs, resistors).
• Understand digital output and GPIO pins on the ESP32.
• Learn basic MicroPython programming (importing modules, loops, delays).
• Develop problem-solving skills through simple debugging.

Detailed Parts List

• ESP32 – 1
• LED (any color) – 1
• Resistor (220 ohm or similar) – 1
• Breadboard – 1
• Jumper Wires – Male-to-Male

Circuit Diagram Description 

Connect the long leg (anode) of the LED to a digital GPIO pin on the ESP32 (e.g., GPIO16) through the resistor. Connect the short leg (cathode) of the LED to the GND pin on the ESP32. The resistor is crucial to limit the current flowing through the LED and prevent it from burning out. 

Software Functionality 

The MicroPython code will initialize the chosen GPIO pin as an output. It will then enter a loop that repeatedly sets the pin high (turning the LED on), waits for a short duration, sets the pin low (turning the LED off), and waits again.

Web Interface Features 

For this basic project, a web interface is not necessary.

Implementation Steps

1. Set up the MicroPython environment on the ESP32.
2. Connect the LED circuit on the breadboard as described.
3. Write the MicroPython code to control the LED.
4. Upload and run the code on the ESP32.
5. Observe the LED blinking.

Extensions and Challenges

• Make the LED blink at different rates.
• Create different blinking patterns (e.g., Morse code).
• Control multiple LEDs with different patterns.
• Introduce a button to turn the blinking on/off.

Troubleshooting Guide

• LED not lighting up: Check the circuit connections, ensuring correct polarity of the LED.
• Verify the resistor value is appropriate. Confirm the correct GPIO pin is used in the code and the pin is set as an output.
• MicroPython code errors: Check for syntax errors in the code. Ensure necessary modules (e.g., machine, time) are imported.

Project Code

# Project 1: LED Control and Blinking Patterns
# This script demonstrates basic digital output control by making an LED blink.

from machine import Pin  # Import the Pin class to control GPIO pins
import time              # Import the time module for delays

# Define the GPIO pin number connected to the LED.
# Replace 16 with the actual GPIO pin you are using.
led_pin = 16

# Create a Pin object for the LED pin and set it as an output.
# Pin.OUT specifies that the pin will be used for outputting signals (high/low voltage).
led = Pin(led_pin, Pin.OUT)

# Define the blinking interval in seconds.
# The LED will be on for this duration and off for this duration.
blink_interval = 0.5

print("Starting LED blinking script...")

# Start an infinite loop to make the LED blink continuously.
while True:
    # Turn the LED on by setting the pin to a high logic level (typically 3.3V on ESP32).
    led.value(1)
    print("LED On")
    
    # Wait for the specified blink interval.
    time.sleep(blink_interval)
    
    # Turn the LED off by setting the pin to a low logic level (typically 0V).
    led.value(0)
    print("LED Off")
    
    # Wait for the specified blink interval.
    time.sleep(blink_interval)

# This loop will run forever until the power is cut or the script is stopped.

STEM Benefits

Science:

• Electricity and Circuits: Students learn about basic electrical circuits, including the flow of current, voltage, and the function of components like LEDs and resistors. They observe how electricity powers the LED.
• Optics: Understanding how an LED produces light (though typically at a basic level in this project).

Technology:

• Microcontrollers: Introduction to the ESP32 as a programmable electronic device.
• Digital Outputs: Learning how the microcontroller’s GPIO pins can be used to control external components.
• Programming: Using MicroPython to write instructions for the microcontroller.

Engineering:

• Circuit Design and Building: Students practice assembling a simple circuit on a breadboard based on a diagram or description.
• System Integration: Connecting software control to hardware output.
• Troubleshooting: Identifying and fixing issues when the LED doesn’t blink as expected.

Mathematics:

• Timing and Delays: Understanding time intervals and how to implement delays in code.
• Counting (implicit): While not explicit, the concept of cycles in a blinking pattern relates to counting.
• Basic Arithmetic (for resistor calculation, if covered): If the project includes calculating the appropriate resistor value, basic Ohm’s Law (V=IR) would be introduced.