““Step 3: Build the Start and Stop Circuit The last piece of this project is the button circuit that starts and stops the LEDs. Make these connections now: Connect one push button at the bottom of the breadboard, across the notch in the middle. Plug the 4011 NAND-gate IC into the breadboard, a couple of rows above the button. Make sure its chip marking points toward row 1 on the breadboard. Place the second button above the IC on the right component side so that it’s easy to reach it with your finger. Connect the two resistors, R13 and R14, as shown in the circuit diagram. Then, use jumper wires to make the remaining connections in the SR latch circuit, as shown in the following breadboard diagram. Connect the positive and negative supply columns to the NAND-gate IC (pins 14 and 7, respectively), and connect the wire from pin 11 of the NAND-gate IC to pin 13 of the 4017 decade counter.””
