i almost invented multiplexing

So first, what on earth is multiplexing?

In simple terms multiplexing is a smart way to send or control several things using fewer resources. Example: allowing your phone to efficiently connect with many bluetooth devices.

The year was 2018 and we were trying to build a small showcase for Pi Day. Elisha Kindars and I, my then classmate, decided we would build a system that would continuously calculate the digits of Pi and display them in a scrolling fashion through an array of four 7-segment displays.

So how do we do this? Each 7-segment has 7 control pins, so for four displays I would need 7 x 4 = 28 pins, right? Well, any average engineer will know that's quite inefficient. But 15-year-old me didn't know that.

The result was the monstrosity you can see in the image. I literally hooked up 2 Arduino Unos, each giving me 14 digital pins to cover all 28 pins.

And if you stay with me, you will realize this creates a new problem -- how the hell do I sync two separate Arduinos when I had already used all the available pins?

The easy answer: add a third one.

But I came up with a clever solution, or at least so I thought at the time.

Instead of relying on digitalWrite(), I used analogWrite() inside a helper function to generate a PWM-based signal after each iteration so that it created a detectable change on the line that the second board could use as a synchronization cue to advance to the next digit of Pi.

But then I came up with an even more genius idea: connect all similar sections of all 7-segments together and only supply power to one segment at a time, so I don't end up with all four segments always displaying the same thing. And boom -- it worked. Instead of 7 x 4 = 28 pins, I now only needed 7 + 4 = 11 pins.

I had made a breakthrough. I had found a way to simplify the circuitry without compromising functionality.

With joy I went to share my discovery with a teacher... but I was quickly humbled when he told me "that's called multiplexing."

Yeah, I was only about 150+ years late to the game.

But you might ask, why didn't I just look it up online? And that's the whole point -- I was in a public school where there was no internet, I didn't have a phone, and the only resources I had were a PDF about C programming and a blink example in Arduino.

But I am grateful, because all these challenges shaped me to become a very resourceful individual who utilized every resource at my disposal -- a skill that later helped me build commercial high-voltage automation systems that I started selling to schools and churches in Tanzania, shortly before I got the most life-changing scholarship to attend UWC Robert Bosch College.

But it's sad that for thousands of passionate Tanzanians out there, access to quality engineering education is still a privilege of the few.

That's why I started teKsafari, and our mission has been mostly driven by my somewhat selfish desire of not wanting my brothers and sisters to keep going through the same cycle of broken foundations -- leading to a country that can't be self-sufficient on even the most basic technological infrastructure.

We have started in Tanzania, already impacting over thousands of young people, but our mission is to spread across Africa.

We have built affordable learning kits, a programming language in Swahili, established open-access makerspaces, set up and supported technical clubs in schools, and so many more.

And I don't take this lightly -- in fact, I take it quite personally, because I know firsthand how it feels to work twice as hard only to be half as good.

And we know this is not an easy problem, especially in Africa where bureaucracy is deeply commoditized.

That's why we need your help.

If you believe in what we are doing, please go pledge your support on our page -- no monetary contribution needed.

Just your email and a short message to the team.

More than anything, we want you with us on this Safari -- the teKsafari -- to share the wins, weather the setbacks, and celebrate every milestone on the road to fixing this broken system, or die trying.

We can't do this alone.