Home Automation with ESP32 - 4 Hour Camp

Audience: Students ages 12-18, no prior electronics experience required
Format: 4-hour camp session (same content runs twice: morning and afternoon)
Group size: 20 students per session
Theme: “Your first real hardware project — code something you can feel, see, and take home”

• Slides
• Resources:
  • Glossary
  • Next Steps
  • Hardware Reference
  • Cost Calculator
• Student Handouts:
  • Vocabulary Handout
  • Worksheet
• Instructor Notes:
  • Common Questions
  • Timing Guide
• Starter Code:
  • LED Blink
  • Random Blink
  • DHT22 + RGB (full project)
  • Serial RGB Control

1. Workshop Goals

By the end of this camp, every student should be able to:

• Explain what a microcontroller is and how it differs from a regular computer
• Wire a simple circuit on a breadboard without help
• Upload code to an ESP32 using PlatformIO
• Read a humidity (and temperature) value from a DHT22 sensor in code
• Drive an RGB LED with PWM to mix colors
• Describe what “home automation” means and give real-world examples
• Take home a working humidity-to-color display they built themselves

2. The Project

Students build a humidity-to-color display: a DHT22 reads the room’s humidity (and temperature), and an RGB LED changes color based on the reading. The firmware drives the color from humidity by default — because students can change it instantly by breathing on the sensor, which makes the cause-and-effect obvious and keeps the room engaged. A one-line switch drives the color from temperature instead for anyone who wants to try it. The finished circuit fits on a single half-size breadboard and runs off a USB power bank, so students can take it home.

Color mapping (starting points — students can customize)

Humidity-driven (default in dht22-and-rgb/):

Temperature-driven (alternate mode):

3. Success Definition

A student is successful if they can say:

“I wired this myself, I uploaded my own code, and it works. I know what each part does.”

The circuit working is the floor, not the ceiling. Students who finish early can customize their color ranges, add Serial output, or explore adding WiFi.

4. Hardware

See hardware.md for full details, pin assignments, wiring diagrams, and component notes.

Each student station needs:

• 1 × Elegoo ESP32 DevKit V1 (Type-C)
• 1 × DHT22 / AM2302 bare 4-pin sensor
• 1 × 5 mm RGB LED, common cathode (4-pin)
• 3 × 220 Ω resistors (one per LED color channel)
• 1 × 10 kΩ resistor (DHT22 DATA pull-up)
• 1 × 400-hole half-size breadboard
• 7 × male-to-male Dupont jumper wires
• 1 × USB-C cable (data + power for programming; just power if using a USB power bank at home)
• Laptop with PlatformIO + VS Code installed

Per-room supplies:

• Extra resistors, LEDs, and jumper wires (spares for mistakes)
• Printed wiring diagram at each station
• Instructor demo station visible from all seats

5. Software Setup

Students need the following installed before camp day (or arrive 30 min early):

• VS Code
• PlatformIO IDE extension for VS Code
  • Alternatively, can use PlatformIO Core (CLI) if preferred
• USB driver for CP210x (Windows and some Mac users)

Linux: install pio (PlatformIO Core CLI)

If students are on Linux, this is the quickest reliable setup for the pio command:

# 1) Install pipx (Ubuntu/Debian)
sudo apt update
sudo apt install -y pipx
python3 -m pipx ensurepath

# 2) Restart terminal, then install PlatformIO Core
pipx install platformio

# 3) Verify
pio --version

If pio is still not found after reopening the terminal:

export PATH="$HOME/.local/bin:$PATH"

To avoid serial-port permission errors when uploading to ESP32:

sudo usermod -aG dialout $USER

Then log out and log back in before testing uploads.

Linux: find the ESP32 serial port

Most boards appear as /dev/ttyUSB0 or /dev/ttyACM0, but it can vary.

Use this quick before/after check:

# 1) With board unplugged
ls /dev/ttyUSB* /dev/ttyACM* 2>/dev/null

# 2) Plug in ESP32, wait 2 seconds, run again
ls /dev/ttyUSB* /dev/ttyACM* 2>/dev/null

The new entry is your upload port.

If nothing new appears, watch kernel messages while plugging in:

dmesg --follow

Look for lines mentioning ttyUSB or ttyACM.

Instructors should test uploads on each laptop the day before camp if possible.

6. Camp Agenda

Total time: 4 hours (240 minutes)

7. Segment Breakdown

0:00–0:20 — Welcome & Goal Demo

Show the finished project running — LED changing color as you hold the sensor. Let students ask questions before explaining anything. Set the tone: “You’re going to build exactly this today.”

• Icebreaker: “Name one thing in your home you wish was smarter or automated.”
• Briefly introduce “Lansing Techster” as a curious co-builder.
• Point out the hardware at each station; don’t let students start wiring yet.

0:20–0:45 — What Is Home Automation?

Slide-driven but interactive. Ask questions; don’t just lecture.

• Real examples: smart thermostats, Philips Hue, motion-sensor lights, door locks
• What makes something “smart”? (sensors + logic + output)
• Where does the ESP32 fit? (tiny, cheap, programmable)
• Introduce the three pieces of today’s project: sensor (DHT22) → brain (ESP32) → output (RGB LED)

0:45–1:10 — Meet the Hardware

Hands-on but guided. Students handle components and follow along as you explain each one.

• Breadboard anatomy: rows, columns, power rails, why no soldering needed
• ESP32: point out the USB port, GPIO pins, onboard LED (GPIO 2)
• DHT22 module: the three pins, why it needs power, ground, and data
• RGB LED: four legs, common cathode, which leg is which
• Resistors: why they matter, how to read color bands (quick version)
• Safety rules: don’t connect/disconnect power while wiring; check your work before plugging in

1:10–1:45 — Build the Blink Circuit

Students wire the onboard LED blink circuit from the printed diagram and upload the starter code from onboard-LED-blink/.

• Walk through PlatformIO: open project, platformio.ini, src/main.cpp
• Upload together; watch Serial Monitor for “LED ON / LED OFF”
• Milestone check: every student should see the onboard LED blinking before moving on
• Common issues: wrong COM port, driver not installed, serial monitor baud rate

2:00–2:30 — DHT22 Sensor (after break)

Add the DHT22 to the existing circuit (it can share the breadboard). No RGB LED yet.

• Wire: VCC → 3V3, GND → GND, DATA → GPIO 4, plus a 10 kΩ pull-up between DATA and 3V3 (the bare 4-pin sensor has no built-in pull-up). Leave the NC pin unconnected.
• Walk through the library setup in platformio.ini
• Live-code reading temperature + humidity in the Serial Monitor
• Milestone check: every student sees real temperature/humidity numbers printing
• Discuss: what would you do with this data? thermostat? weather station?

2:30–3:05 — RGB LED + Color Logic

Add the RGB LED circuit (three resistors, three GPIO pins). Write the color-mapping function together.

• Wire: R → 220 Ω → GPIO 18, G → 220 Ω → GPIO 19, B → 220 Ω → GPIO 23, cathode (longest leg) → GND
• Introduce ledcSetup / ledcAttachPin / ledcWrite (LEDC PWM) for color mixing
• Test each channel individually first (red only, green only, blue only) — the firmware’s startup self-test cycles R → G → B for exactly this reason
• Introduce the humidity (default) and temperature thresholds and color mapping
• Write setColor(r, g, b) helper together
• Milestone check: LED changes color when you breathe on the sensor (humidity mode) or warm it with your hand (temperature mode; less sensitive)

3:05–3:30 — Integration + Debugging

Combine the DHT22 read with the color logic in one loop().

• Students who finish fast: encourage exploring intermediate colors (orange between red and yellow)
• Common bugs: wrong pin numbers, cathode vs anode confusion, library not installed, DHT read returning NaN
• Walk the room; don’t fix bugs for students — ask guiding questions

3:40–3:55 — Personalization

Students customize something about their project:

• Adjust the humidity (or temperature) thresholds to match their preference
• Add a slow color fade instead of instant switch
• Print a custom status message to Serial (e.g., “Brendon’s room: HUMID”)
• Experiment with mixed colors (orange, purple, teal)

3:55–4:00 — Wrap-Up

• Quick show-and-tell: a few students demonstrate their project
• Explain how to keep the project running at home (USB power bank)
• Point to next steps resources
• Hand out any printed reference cards

8. Instructor Logistics (Two Sessions)

Morning session prep (before students arrive):

• Verify every laptop has PlatformIO and can upload to an ESP32
• Pre-load the starter project on each laptop so students don’t spend time cloning
• Set out hardware kits at each station with a printed wiring diagram
• Test your own demo circuit is working

Between sessions (turnaround ~30 min):

• Collect any hardware left behind
• Restock any blown LEDs or missing resistors
• Reset demo station if anything was modified
• Quick mental debrief: what questions came up? adjust pacing if needed

Energy management across both sessions:

• Morning groups are usually sharper; afternoon groups sometimes need more energy from instructors
• The break segments are non-negotiable — hardware fatigue is real
• Keep the “show the goal first” demo for both sessions; it anchors motivation

9. Differentiation

Students who finish early:

• Add smooth color fading (interpolate between colors using PWM values)
• Add a WiFi connection and POST humidity data to a free webhook (e.g., webhook.site)
• Display humidity on the Serial plotter instead of monitor

Students who struggle:

• Pair with a neighbor or have a pre-wired “fast start” circuit ready
• Focus on getting the blink working; the DHT22 + LED can be a demo they watch
• Cut scope before cutting confidence — a working blink is a win

10. Materials Checklist

• Hardware kits assembled and counted (20 per session + 5 spares)
• Printed wiring diagrams (one per station, laminated if possible)
• Printed vocabulary handouts
• Laptops charged and software verified
• Instructor demo station assembled and tested
• USB power banks for take-home use (optional but great)
• Ziploc bags for students to take hardware home