16x2 LCD (I2C)
Displays
16-character, 2-line text display using the standard HD44780 controller.
5V Relay Module
Power
Single-channel relay board that lets a low-voltage logic signal (5V) switch a high-power AC or DC load.
7-Segment Display
Displays
Displays a single digit (0-9) using 7 LED segments plus a decimal point.
74HC595
ICs
8-bit serial-in, parallel-out shift register.
A4988
Modules
Microstepping bipolar stepper motor driver module.
Arduino Uno R3
MCUs
The classic beginner microcontroller board, built around the ATmega328P chip.
BNO086
Sensors
9-axis IMU with on-chip sensor fusion — outputs ready-to-use orientation data.
CD4017
ICs
CMOS decade counter/divider IC.
DHT11
Sensors
Simple digital temperature and humidity sensor.
ESP32-WROOM-32
MCUs
Common ESP32-WROOM-32 38-pin DevKit V1 layout.
ESP8266 (NodeMCU)
MCUs
Cheap Wi-Fi microcontroller board built around the ESP8266 chip, the predecessor to the ESP32.
HC-SR04 Ultrasonic
Sensors
Ultrasonic distance sensor — sends a sound pulse and times the echo to measure distance.
HC-05
Modules
Serial (SPP) Bluetooth module for wireless UART communication.
L293D
Modules
Dual H-bridge motor driver IC.
L298N
Modules
Dual H-bridge motor driver module.
LM2596
Power
Adjustable step-down (buck) converter module.
LM358
ICs
Dual operational amplifier IC.
MT3608
Power
Adjustable step-up (boost) converter module — the opposite of the LM2596.
NE555
ICs
The classic 555 timer IC used to generate precise time delays or oscillating signals.
Nokia 5110 LCD
Displays
Small 84x48 monochrome LCD, from Nokia phones, now sold as a cheap breakout module.
Raspberry Pi Pico
MCUs
Small, cheap microcontroller board built around the RP2040 chip.
Soil Moisture Sensor
Sensors
Two-part module — a probe that goes into soil, plus a small board that reads it.
SSD1306 OLED (128x64)
Displays
Small monochrome OLED display driven by the SSD1306 controller.
TP4056
Power
Single-cell Li-ion/Li-Po battery charger module.