How to Make a Digital Counter Circuit

Step-by-Step Guide

1. 1

   Step 1: Create 2 buttons labeled increment and reset.

   Connect these both to an OR gate.
2. 2

   Step 2: Create 14 AND gates and 15 RS flip-flops.

   Connect the increment button to each AND gate. , Now match each AND gate output to one S input on each RS flip-flop. ,, At this point you should have 14 AND gates with 1 open input, and 15 RS flip-flops with no open inputs, and 2 open outputs. , Give each of the 4 OR gates 8 inputs and connect each or gate’s output to one of the numerical display inputs. , Follow this pattern for each following set of gates. , Ignore the last gate for now. ,, For example, the 5th XOR gate will connect to OR gate 3 and OR gate 1, resulting in a binary output of
   0101.
   
   Binary Values Binary Number 0000 0 0001 1 0010 2 0011 3 0100 4 0101 5 0110 6 0111 7 1000 8 1001 9 1010 10 1011 11 1100 12 1101 13 1110 14 1111 15 , Every click of the increment button will increase the counter’s value by 1 from 0-15(F).
   
   The reset button will clear the current value back to 0 allowing you to begin incrementing again.
3. 3

   Step 3: Connect the increment button to the S input on the first RS flip-flop.

4. 4

   Step 4: Connect the reset button to every R input on each RS flip-flop.

5. 5

   Step 5: Connect the single OR gate output to the clock input on each RS flip-flop.

6. 6

   Step 6: Create 14 XOR gates

7. 7

   Step 7: 4 OR gates

8. 8

   Step 8: and one numerical/number output.

9. 9

   Step 9: With the first SR flip-flop’s Q output (not Q`)

10. 10

    Step 10: connect it to one input of the first XOR gate

11. 11

    Step 11: and one input of the first AND gate.

12. 12

    Step 12: For each following RS flip-flops

13. 13

    Step 13: connect the output to: an input of the previous XOR gate

14. 14

    Step 14: an input of the next XOR gate

15. 15

    Step 15: and the input of the next AND gate.

16. 16

    Step 16: On the last RS flip-flop the only connections it will have is one to the last XOR gate

17. 17

    Step 17: and one to each of the 4 OR gates.

18. 18

    Step 18: Connect each XOR gate to the corresponding OR gates that would create it’s number in binary.

19. 19

    Step 19: You’re done!

Detailed Guide

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