The 555 is our first steps into chips. The 555 is a timer chip, this means that it will ‘tick’ like a clock. We will use this to turn an LED on and off.
The chip has 8 pins. The pins are numbered down one side 1,2,3,4 and up the other 5,6,7,8.
The circuit we will use is also available on Instructables which also includes the breadboard layout.
https://www.instructables.com/id/Flashing-LED-using-555-Timer/