Arduino Mega 2560 Rev3 · ELEGOO Most Complete Starter Kit · 29 parts
The board
Click any pin to see what it does and which kit parts use it, or light up pins by function with the buttons below. Each pin has its own link you can share. Press ? for keyboard shortcuts.
Board revisionMega 2560 Rev3, current datasheet
29 parts · colour-coded by type
Kit parts
Pick a part for its pinout, the resistors it needs, and the wiring from its kit lesson.
Which resistor, and where
Resistors
Every Mega pin can supply 20 mA at most. A resistor keeps LEDs and displays under that, and holds inputs at a steady level.
Quick rules
| What you're connecting | Resistor | Where |
|---|---|---|
| An LED (any colour) | 220Ω | In series with the LED, on either leg |
| RGB LED | 3 × 220Ω | One on each colour leg |
| 7-segment display | 220Ω each | On the segment pins, or the digit pins (see the display's page) |
| Button or switch input | None | Use INPUT_PULLUP, or a 10kΩ pull-down to GND |
| Thermistor or photocell | 10kΩ or 1kΩ | From the analog pin to GND, forming a divider |
| Transistor (PN2222, S8050) | 1kΩ | Between the Mega pin and the base |
| Sensor modules | Usually none | They have their own resistors on board |
LED resistor calculator
Resistors in the kit
1% metal film with 5 colour bands. Read them with the brown tolerance band on the right.
Every part, and the resistors it needs
Where the facts come from
Sources
The board facts come from Arduino's current Mega 2560 Rev3 documents (datasheet rev 4, 20 Oct 2026) and the ATmega2560 datasheet. The kit wiring comes from the pin numbers in ELEGOO's own lesson sketches (download V1.0.2023.05.05). Links marked PDF copy are datasheets from ELEGOO's kit download, hosted here for convenience. They belong to ELEGOO and the original manufacturers.