This example uses three LEDs to make a model traffic light signal. You can use all red LEDs if you like, but its more realistic if you use red, yellow and green.
The LEDs cycle around in the sequence red, green, yellow and then back to red again
You will need the following parts:
1x Micro B USB Cable
3x Jumper Wire
1x Red LED
1x Yellow LED
1x Green LED
To add the extra LEDs and resistors, wire them up as shown in the breadboard layout below.
Ensure that the LEDs are the right way around, with the longer positive leads (anodes) to the left.