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Arduino LED Lab

Uno R4 lessons — on lesson 4: safe resistor values for LEDs.

  • Electronics
  • Coding
  • Arduino
BuildingBUILD LOG #05

// What I'm building

I'm learning Arduino with an Uno R4 by following an online lesson series. I'm on lesson 4.

I learned which resistor values keep an LED safe, and why: the resistor limits how much electricity flows, so the LED doesn't burn out.

Every LED needs a resistor buddy. A common pick for an LED on a 5V pin is around 220Ω–330Ω.
  • Arduino Uno R4
  • Online lesson series — lesson 4
  • LED + resistor circuits
UNO R4 220Ω

// Build Log

  1. Lessons 1–3 — getting started

    WHAT I TRIED
    Set up the board and worked through the first lessons.
    WHAT BROKE
    —
    THE FIX
    —

  2. Lesson 4 — safe resistor values

    WHAT I TRIED
    Learned resistor values for LEDs and why they matter.
    WHAT BROKE
    Without a resistor, an LED can get too much current.
    THE FIX
    Use the right resistor every time.
NEXT STEP

Keep going with the lessons. Next big idea: an electromagnet (with a grown-up).