About Bench Notes
An independent, practical reference for building circuits with the Arduino Uno R3 and compatible boards.
What is here
35 articles in 7 topics. Each tutorial has an overview, a parts list, a wiring table, an original diagram, a complete sketch with a copy button, an explanation of the code and a list of what you should see when it works.
The Workshop Projects are eight sketches with deliberately compact wiring: a potentiometer plugged straight into A0/A2/A4 and an LED between pins 11 and 12. Their code is reproduced unchanged; each article records what was checked.
Safety basics
- Every LED and every seven-segment segment needs a current-limiting resistor unless the part has one built in.
- Keep each I/O pin at or below about 20 mA, and the whole board's pins under about 200 mA.
- Motors and larger servos need their own supply, with its ground connected to the Uno's GND.
- Check polarity: LEDs, electrolytic capacitors, sensors such as the TMP36, and display types (common anode or cathode).
- Make wiring changes with the USB cable unplugged.
Independence
Bench Notes is not affiliated with, endorsed by or sponsored by Arduino, any educational institution or any component maker. Product names are used only to identify compatible parts.
Using the code
Every sketch on this site may be copied, changed and shared without asking. The examples target the Arduino IDE with the board set to Arduino Uno; the Servo and Wire libraries come with the IDE.