Boards and essentials
Jumper wires
Short reusable leads connect boards, breadboards, and modules.
What it does
Male ends enter breadboard holes; female ends fit exposed header pins. The conductor has no preferred signal direction.
Connections and compatibility
Choose male-to-male for breadboard connections and female ends where modules have pins. Keep SPI and I²C wiring short.
Choosing one
A mixed set is useful across many builds. Inspect loose crimps and damaged insulation before replacing a supposedly failed sensor.
Common mistakes
Wire color is a convention, not proof of function. Follow pin labels and confirm ground continuity.
Use it in a tutorial
- Analog and PWM signals — Use a potentiometer to control an indicator, and learn how analog measurements differ from PWM outputs.
- Buttons and switches — Wire a button with an internal pull-up, debounce it, and toggle an indicator once per press.
- Blinking an LED — Wire a low-current status indicator and blink it without blocking the rest of your program.
- Passive infrared (PIR) motion sensors — Read an HC-SR501 motion sensor and learn why movement detection is different from occupancy.
- Infrared receiver modules — Decode an old remote with a 38 kHz receiver and distinguish new presses from held-key repeats.
- Servo motors — Move a lightweight pointer with two buttons while powering a micro servo independently of the controller.
- Convert a servo to continuous rotation — Understand a servo conversion, calibrate neutral, and control continuous rotation with a short timed run.
- Stepper motors — Move a 5 V 28BYJ-48 with a ULN2003 driver, starting slowly and accounting for missed steps and backlash.
- Shift registers — Use a 74HC595 to drive eight low-current indicators with three controller pins.
- Transistors — Build a low-side transistor switch, then learn what changes when the load becomes a motor or relay.
- Ultrasonic distance sensors — Measure distance with an HC-SR04, reject missing echoes, and compare raw readings with a small median filter.
- Using an LED matrix module — Show readable status symbols on a MAX7219 matrix instead of adding a full screen.
- Using an analog joystick module — Read a thumb stick, calibrate its resting center, and add a dead zone for stable controls.
- Using rotary encoders — Decode a mechanical knob’s direction and count complete quadrature cycles without mistaking every bounce for a turn.
- Using an RFID module — Read an RC522 tag identifier with correct voltage translation, and understand why a UID is not a secure key.