Help with flashing LED circuit design.
Basically, there will be 9 LED's in total, 3 in each row. It will be powered by a 9v battery. The LED's are 2.2v 50mA.
So I want the 3 LED's in Row 1 to illuminate.
Then Row 1, de-luminate fully, then Row 2 to illuminate straight after.
Then Row 2, de-luminate fully, then Row 3 to illuminate straight after.
Then start over again, so it's basically a sequence of 1,2,3,1,2,3,1,2,3 etc.
From what I understand a 555timer is required?
I'm looking to do this as cheap as possible Any help or guidance would be appreciated.