need to know what resistor to use for my project

Using Arduino General Electronics
3

Thanks. (Can't go to RS now- a blizzard on US EAST COAST!)
The project is a simple led flasher. From book "beginning arduino "
The hardware used in Project 1:

Breadboard

5mm LED

100 ohm Resistor*

Jumper Wires

  • or whatever value appropriate for your LED

The code is:

Listing 2-1. Code for Project 1

// Project 1 - LED Flasher
int ledPin = 10;
void setup() {
pinMode(ledPin, OUTPUT);
}
void loop() {
digitalWrite(ledPin, HIGH);
delay(1000);
digitalWrite(ledPin, LOW);
delay(1000);
}