A free directory of hardware builds for Hi Bot Code makers. Default assumption: an ELEGOO ESP32 Super Starter Kit — plus USB cable and Arduino IDE.
The ESP32 is a tiny computer with Wi‑Fi and Bluetooth built in. You write code on a laptop, upload it over USB, and the board runs that program forever (until you upload something new). This listing stays free and open — no account, no paywall, remix anything you like.
When a project could go many ways, we pick parts that ship in a typical ELEGOO ESP32 Super Starter Kit: LEDs, buttons, resistors, buzzers, DHT11, OLED, ultrasonic, servo, stepper, PIR, IR remote, RFID, joystick, relay / motor driver, breadboards, and jumper wires.
Kit note: Exact bag contents vary by kit revision. If something is missing, swap for the closest part (passive buzzer ↔ active buzzer, single‑digit display ↔ OLED) and note the change in your build log. The IMU bag may say GY‑6500 — verify silicon with WHO_AM_I before loading an MPU‑6050‑only library.
Start where you are. Intro is “get the board talking.” Beginner is wiring + simple code. Intermediate combines sensors and actuators. Advanced leans on Wi‑Fi, RFID, and systems thinking.
Do these once. Skip nothing. Every later project assumes Serial works and you can upload without panic.
Prove the pipeline: IDE → USB → ESP32 → LED toggles.
setup().Change the blink rate with a constant at the top of the sketch so classmates can tweak it in one place.
Read an input cleanly and drive an output only when you mean to.
INPUT_PULLUP (pressed = LOW).Toggle mode: one press latches LED on, next press offs it — still ignoring bounce.
Simple loops, one idea per project. Great classroom pace: one build per session.
Mix red, green, and blue with PWM so the color responds to a pot.
Add a button that freezes the current color as a “favorite.”
Lights turn on when the room gets dark — no clock needed.
Use two thresholds so the light does not flicker at the edge of darkness.
Play tones — then a short melody when a button is held.
ledcWriteTone — classic AVR tone() is unreliable on older ESP32 cores.playNote(freq, ms) and test a C major scale.Encode a secret doorbell pattern: three short presses unlock a victory beep.
Read temperature and humidity and print a clean Serial dashboard.
Temp: xx.x C | Humidity: yy%.Drive a status LED green/amber/red based on comfort ranges you define.
Turn a knob; the servo mirrors the angle like a volume needle.
servo.write(angle).Add a soft‑start: first 2 seconds always ease from 90° to the pot angle.
Now sensors decide actuators. Expect longer wire lists and small state machines.
Beep faster as you approach a wall — optional OLED distance readout.
pulseIn (prefer this over NewPing on ESP32). Convert to cm; print to Serial and OLED.Draw a simple bar graph on the OLED instead of only numbers.
Motion turns on a light for N seconds, then fades the LED out with PWM.
analogWrite).Log motion events with timestamps over Serial like a tiny security journal.
Joystick X or Y drives a servo; dead zone keeps it still at center.
Map the unused joystick axis to Serial/OLED as a second “virtual” tilt readout (same single SG90). A true pan‑tilt mount needs a second servo — extra part, not in the default kit bag.
Decode kit remote buttons; each button picks a device mode.
Remember the last mode in RTC memory / Preferences so power cycles restore it.
When temperature rises, spin the DC fan via L293D (or transistor).
Three speeds: off / half PWM / full — driven by temperature bands.
Multiple modules, clearer product goals, and the ESP32’s radio. Plan wiring before you power on.
Serve a tiny HTML page from the ESP32 showing live DHT11 readings.
/ that returns HTML with temperature and humidity./json for machine‑readable values — useful for later dashboards.Auto‑refresh the page every 5 seconds with a meta refresh or tiny JS fetch.
Only enrolled cards unlock a servo latch; OLED shows status.
Enrollment mode: hold a boot button to add the next scanned UID to flash (Preferences).
Sweep a stepper turret, sample distance each angle, plot a crude radar on Serial/OLED.
pulseIn, record angle→distance.If any reading < 15 cm, freeze, buzz, and reverse direction.
GY‑6500 (often MPU‑6500 silicon) pitch & roll on the OLED with a virtual horizon.
Log a 10‑second “maneuver” to Serial as CSV for science lab graphs.
Combine PIR + DHT + OLED + buzzer + Wi‑Fi status page into one “classroom monitor.”
/ and /status over Wi‑Fi so a phone can check the room without Serial.Write a one‑page lab report: wiring photo, state diagram, and what broke first.
Classroom tip: advanced builds pair well — one student owns sensors, one owns UI/Wi‑Fi, then integrate. Keep a shared wiring diagram on paper before anyone reaches for the breadboard.
Pick a project, finish the stretch goal, and take a photo of your breadboard. Share it in class or on the Showcase when you connect the hardware story to a web project.
Attribution: This directory is free and open for teaching and remixing. ELEGOO is a third‑party kit maker — we are not affiliated; kit contents are a practical default so classrooms stay on one BOM. Prefer local purchase options that fit your school’s purchasing rules.