# Trying to make logic gate educational components, like Snap Circuits

#### michael_kantor

Joined Mar 20, 2018
1
I am working on a project with my son (12), and we would like to make individual logic gates that can be wired up easily into various combinations. Something like the Snap Circuits components, but with logic gates. We will need a lot of them - perhaps 30 gates of various types.

I know that we could design and make small PCB boards, and mount an IC and connectors on each, but I'm not sure how to handle the power supply. In an ideal world, I'd like to have students just hook up the signal wires and not be bothered by power.

I have searched, but aside from a some very expensive sets with very few gates, I have not found anything. Is such set of logic gate components available? Or does anyone have a proven design for constructing such components?

#### crutschow

Joined Mar 14, 2008
23,502
The easiest may be just to use a solderless breadboard with CD4000 CMOS series logic gates in DIP packages.
The CD4000's are fairly tough and can operate from a 3V to 15V supply.
They take virtually no current so can be operated from a 9V battery for a very long time.
They can drive high brightness LEDs at a mA or so, which is sufficient to make them readily visible to show the state of a circuit output.
Of course you must add a resistor in series with the LEDs to limit their current.

You do have to wire power and ground but that shouldn't be a real problem.
Some of the wireless breadboards have banana terminals for the power and ground rail.

One cautionary note is that all CMOS devices must have all their unused inputs (not outputs) connected to ground, or they can act flakey.
Edit:
Or you can add 50kΩ resistors on each input to ground. That will keep them at ground if they have no input, but can be readily driven high by the output from another gate.

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Joined Mar 10, 2018
3,609
You could use a PSOC, it has ability using GUI tool to drag and
drop gates, flops, or more MSI like components, onto design canvas
and wire up to its pins, eg. its routable.

Its a general purpose micro, but with a lot of capability, and for simple gates
you would not have to write any code. Plus it has lots of analog.

Tool, "Creator" is free, two boards come to mind, low end PSOC 4, and high
end PSOC 5LP.

http://www.cypress.com/products/psoc-creator-integrated-design-environment-ide

http://www.cypress.com/documentation/development-kitsboards/cy8ckit-042-psoc-4-pioneer-kit $30 http://www.cypress.com/documentation/development-kitsboards/psoc-4-cy8ckit-049-4xxx-prototyping-kits$4
http://www.cypress.com/documentation/development-kitsboards/cy8ckit-059-psoc-5lp-prototyping-kit-onboard-programmer-and \$ 10

Last board most capable part, but all boards would do the logic capability.

Attached is a component list (a component is a design element inside psoc, a resource) that you
can drag and drop onto canvas. It applies to high end part PSOC 5LP, PSOC 4 has a subset of
these resources.

PSOC 101 video series, lessons 1 - 16.....

http://www.cypress.com/video-library/PSoC/psoc-101-introduction-psoc-101/387726

Regards, Dana.

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#### dl324

Joined Mar 30, 2015
9,121
Welcome to AAC!
aside from a some very expensive sets with very few gates, I have not found anything
Post pictures or links to what you found suitable, but too expensive. This will help bound solution space.

What is the target audience age group?

What kind of training will they be given before being turned loose to create circuits?

Will they be likely to harm themselves or others if given pointed objects like wires?

Will they be old enough to follow written and verbal instructions?

What kind of gates (AND, OR, NOT, XOR, NAND, NOR, XNOR) are you planning to use? How many inputs? How many of each?