ESP32 operates at 3.3V logic. Do NOT connect 5V signals directly to GPIO pins.
GPIO pins source/sink max 40mA each. Total across all pins: 1200mA.
VIN pin accepts 7–12V (onboard regulator). Max 2A.
The 5V pin provides regulated 5V output (when powered via VIN or USB). Max 500mA from USB.
2 · Power Supply Precautions
Never connect an LED directly to a GPIO pin without a current-limiting resistor (220 ohm is typical for the kit's LEDs).
Use external power for motors, relays, and high-current loads. The ESP32's onboard regulator cannot handle motor surges.
Relays: Use optoisolated relay modules. The relay coil draws more current than a GPIO can supply; always drive it through a transistor or use the module's built-in driver.
3 · Electrostatic Discharge (ESD)
The ESP32 is somewhat ESD-sensitive. Touch a grounded metal surface before handling the board.
Avoid working on carpet or synthetic surfaces without ESD protection.
Handle ICs and bare boards by the edges.
4 · Wiring Safety
Double-check wiring before powering on. A misplaced wire can destroy the ESP32 or connected components.
Use the breadboard power rails correctly: red for VCC, blue/black for GND.
When connecting sensors, match voltage levels: most kit sensors are 3.3V-compatible, but always check.
Disconnect USB power before making wiring changes.
5 · Wireless Safety (Wi-Fi / Bluetooth)
The ESP32's radio is FCC/CE certified. Do not modify the antenna or enclosure.
Be mindful of wireless security: use strong passwords for Wi-Fi projects.
Telegram Bot tokens and Ubidots tokens are like passwords. Keep them in placeholders, never commit real tokens to a repository.
6 · Thermal Safety
The ESP32 can get warm during continuous Wi-Fi transmission. This is normal.
If the board becomes hot to the touch, disconnect power immediately and check for short circuits.
Do not operate the board in enclosed spaces without ventilation when drawing significant current.
7 · General Lab Habits
Always wear safety glasses when cutting wires or working with power tools.
Keep liquids away from the electronics workspace.
Work in a well-ventilated area when soldering (this kit uses no-solder breadboards, but future projects may).
Unplug the USB cable when not in use to prevent battery drain (if using a power bank) and to extend component life.
8 · Component-Specific Notes
Buzzer: The active buzzer has a fixed tone. Do not apply reverse polarity.
PIR Sensor: The Fresnel lens is delicate. Do not press or scratch it.
OLED Display: The SSD1306 module is I2C-only. Do not attempt SPI wiring without checking the module variant.
DHT11: Readings take ~1–2 seconds. Do not poll faster than 1 second.
Relay Module: The relay clicks on/off. This is normal mechanical operation. Do not place near audio equipment.