I signed up for Unravel The Code with a lot of ideas in my head, but not enough skill for what I want to do, so I thought it’d be smart to take an Intro to Robotics class at the same time (it was a smart choice). The class is being taught by Lucas Haroldsen, he graduated from MICA sculpture program and he’s pretty cool. So on Tuesday, I did my first tutorial on electronics in class with different ways to set up LED lights. After the tutorial we were given assignment to put together a circuit based on a couple of schematic drawing options to build from a couple of basic components (transistor, potentiometer, a couple of different motors, lights, and a photoresistor) to work with. I was very fired up about the idea of my first robot I finish a week worth of assignment in one night. I didn’t talk to anyone. Am I turning into a robot? Find out at the end of the class!
So this was one of the schematics that I chose to do:
Which is which, what is what, I had no idea what was going on. But it’s an introductory class for a reason so it came with a drawing:
Nice, right? So I did my best and prototyped it on my breadboard:
I had trouble with the transistor, but after a couple of tries and when everything finally worked out, it felt like jesus was born again. it’s also interesting to see components that look exactly the same but work differently and make an entire circuit works in a different way.
“By turning a small input current into a large output current, the transistor acts like an amplifier. But it also acts like a switch at the same time. When there is no current to the base, little or no current flows between the collector and the emitter. Turn on the base current and a big current flows.” (src: explainthatstuff.com)
So I used the PNP transistor to switch the current to go to the base from emitter (which is connected to the photoresistor) to the collector (the output, here I chose a small motor that functions like a vibrator) and while in the day bug (using NPN transistor) the motor runs when the photoresistor is exposed to light, the PNP transistor switched it around so current flows when the photoresistor does not receive any light. Honestly, I don’t really know how it works, but at least I could understand the flow of the current so I could do my own troubleshooting.
After making sure the circuit is good on the breadboard, I put it together on a tiny copper clad board. Took me a little time to get used to soldering but it feels just like a small TIG welder:
I am still impressed at how all of these things could fit in that tiny board (and how I didn’t burn my hand or anything nearby). I’m so proud of it.
That was my first baby step and journey into making robots, and I definitely will go beyond the class and make more.