Introduction: 16-Stage Decade Counter Chain - Using Two 4017 Chips
Objective and Motive:
I really like how binary counters can link together in chains. For example, if you have two 8-stage binary counters, you can use them together to easily make a 16-stage binary counter.
I always wanted to do that with decade counters. And today I found a way to do this!
Step 1: Gather the Parts
• lots of jumper wires
• two 4017 decade counters
• one 555 timer
• two 0.1 µF capacitors (#104)
• one 10 µF capacitor
• one 1 nF capacitor (#102)
• five 10KΩ (or anything between 4.7kΩ and 22kΩ)
• three N-channel mosfets
• one switch
• one or two breadboards
• one 5V power supply
With these in hand, you should be ready to make a 16-stage decade counter!
Step 2: Examine the Schematic
Take a look at this schematic to see how the components fit together.
You can click on the schematic picture to see a full-size version.
The 16 green wires on the right of the schematic are the 16 outputs.
I suggest you put 16 LEDs on those outputs with 1KΩ resistors in series to monitor the outputs of this device.
If you don't know how to read schematics, I suggest following this tutorial:
Collin's Lab: Schematics
Step 3: Build Your Circuit
Now that you have looked over the schematic, you are ready to build the circuit.
Assemble the circuit on a breadboard using jumper wires to connect components.
I recommend referring back to the schematic while building your circuit on your breadboard.
If you can pack your LEDs together tightly, it will save you some breadboard space.
In the end, I had to expand to using a second breadboard because my LEDs took up so much space.
I'm getting some LED bar graphs to fix this problem :)
Step 4: Expanding the Chain of Decade Counters
I'm fairly sure that it is possible to expand this indefinitely. If you wanted to hook up 3, 4, or 5 4017's together, there is not reason why that shouldn't work.
One limitation is that each decade counter can only contribute 9 states to the overall number of states of the machine.
This is because in order for the device to function, it relies on one state to stop on.
It requires a state to reach and become stuck at until another 4017 resets it.
Keep in mind: whatever state you stop on, only the states before it will be useful.
i.e. If you have your 4017's stop on their 7th state, you would have a total of 6 usable states per chip for a total of 12 states.
For example, the device I built uses the 9th state to stop.
I completely disregard the final 10th state because I only need a total of 16 usable states (8 states utilized per 4017 chip)
However, if you are building a device that needs 36 states, you could use 4 decade counters that use the final 10th state to stop on.
Therefore you have 9 usable states per 4017 chip and have a total of 36 usable states.
Step 5: How the Reset Switch Works
The reset switch works by resetting your first decade counter and advancing the second decade counter up to its 9th position very fast.
It does this by removing capacitance from the 555 circuit with increases the clock frequency a TON.
In the same flip of the switch it also resets the first decade counter, thus stopping it from counting and getting it back to its 1st position.
Simply put, the device resets one 4017, and advances the other to its maximum state.
Step 6: Do Something With Your 16-Stage Decade Counter!
I'm planning on making my 16-stage decade counter into a drum synth.
There will be 16 beats in each measure.
The decade counter will count through all 16 beats and play a rhythm.
Those are my plans for this device, but what are YOURS?
Do you have any ideas that might work with this device?
Let us know below in the comments!
And if you are building your device, don't forget to post a few pictures while you are at it! :P
Step 7: Wrapping Up
The project has been built! (i hope)
The time has come to put away all the junk that must have accumulated on your bench; we clean our benches so that we might design some other device another day.
If you want to see all of the pictures I have taken of this project, check this out:
Full imgur Album
Did something go horribly wrong?
Let us know down in the comments!
Hopefully we can get something working for you. :)
Thanks for reading!
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