Arduino Logic Gates

I want to use the Arduino to build examples of logic gates in the hope I can create a Arduino project that can have multiple inputs to demonstrate complex logic circuits and help demonstrate the simplification of complex boolean algebra statements.

I looked for help online and found useful, but basic circuit diagrams and Arduino code on instructables.com.

The project that appealed the most was a universal logic gates implementer, with 3 input buttons and mulitple where complex logic circuits could be entered and tested.

The design appeared quite straight forward:

I applied this to my Arduino, but it would not work:

My main problem was I didn't really understand what the circuit was doing, so I decided to go back to basics and create a simple NOT circuit which worked and I was able to manipulate the code:

I then got more ambitious and attempted to use 2 inputs and create AND and NOT gates based on the following diagram:

At first this didn't work at all:

Again, my inexperience left me unsure why. With the NOT gate, it didn't work so well at first because the LED was plugged in the wrong way, but this wasn't the case with this circuit. So, I built it again, using the opposite side of the breadboard. Amazingly, this worked, below is the OR gate working.

And below is the code for and AND gate

Which can be seen working below:

My make Part 1: what's a resistor

I have now started investigating my own Make. I decided to buy an Arduino Starter kit from Elegoo . The reason for this is because the area of difficulty I have most with my subject is teaching the simplification of Boolean Algebra expressions. After my first make involving circuit boards, I am interested in seeing if I can create a simplify complex circuits using the Arduino and breadboard to help both my knowledge and the knowledge of my students.

I am going to go through the instruction manual, project by project. But the first thing I have learnt is what a resistor does, which I never knew before.

Basically, resistors come in many sizes of Ohm, from 1 to 1 megaOhm (roughly a million Ohms). I did a series of experiments using different resistors to power a red LED to show the lower the Ohm resistance in the resistor, the brighter the light will be:

Here I'm using very low resistance and the light is very bright.

But in this photo, I am using a resistor with more resistance and the light is not as bright.

Without the resistor, the power going to the LED would probably burn out the LED and destroy it.

After this I experimented with a RGB LED, which can generate any light colour. To do this I had to program the Arduino to change the shades of red, blue and green lights:

Initial impressions: The breadboard is very fiddly to use and it can be difficult to get the pins into it. My eyesight also struggles with the small writing and holes and I think I will need to use a bright lamp to see everything more clearly.

Session 3 - Task 1

The three main questions framing the day were:

What are the strengths / the benefits of using Making as a pedagogical tool?
What are the weaknesses / the limitations of using Making?
Are there topics which cannot (or ought not) be addressed through a Making pedagogy?

We were first introduced to the concept of polyrhythms and the ratios required to make them. After this, we split into 2 groups for different activities. In my group, we did an eTextiles activity to create a bag with flashing poly-rhythmic lights which used a version of the Arduino Lilypad.

After examining a pre-made model, we cut material from a pair of old trousers.

We then sewed conductive thread in the material to allow a circuit to be made in the textile.

It looked like this after the conductive thread was added:

Whilst Salma and I were doing this, the other pair in our group were programming the polyrhythm algorithm for the lights to blink and testing it worked on a paper based example:

Then we hit a tricky spot, hand stitching the LED lights onto the bad using conductive thread.

The conductive thread would fray extremely easily, making it nigh on impossible to thread through the needle we used. Everyone got frustrated, but David persevered and created a working bad with 2, rather than 4, lights which flashed polyrhythmically. 

So, lets answer the original questions:
What are the strengths / the benefits of using Making as a pedagogical tool?  Well, the bag was quite impressive when completed and would naturally lead to the requirement of not just how you made it, but also why the lights blink in the order they blink in. This takes learning away from simply doing and internalising, to doing, internalising and then explaining, which is quite a leap.

What are the weaknesses / the limitations of using Making? That bloody conductive thread! I lost patience, so I imagine students would to. Huge amount of preparation would be needed too, but the bag looked great. We estimated you would need at least 8 hours or 1 whole term to complete this project with a class.

Are there topics which cannot (or ought not) be addressed through a Making pedagogy? We looked predominantly at Maths as a theme, introducting textiles, computer science, design technology and a bit of physics, which isn't bad for one task.