As of late November 2014, I got a new job in an interactive agency with a job title “experiential media specialist”. I shall henceforth be known as the “electronics guy”, the one wielding a soldering iron. See, I even got my own tool bag.
And this is my workbench.
This role has very much to do with hardware – wires, buttons, sensors, tangible interfaces and so on. It is very different from my previous job which had to do with software, when I was an interface programmer. It could potentially be more exciting I guess. I will be touching physical objects, going on site to setup stuff, and shop for parts, very different from sitting at a desk programming all day. But we’ll see.
So during my first week into the job, as part training, I was asked to create a circuit. What this circuit does is that you light up a bunch of big arcade buttons whenever they are pressed. The arcade button LEDs run on 12V powered by a wall adaptor. You need something like an Arduino to act as a micro-controller, so that whenever the buttons are pressed, a relay circuit will allow the wall adaptor to close the circuit with the LEDs and turn them on.
First things first. I have no idea what a relay circuit was. As a result, in my years of using the Arduino, having never damaged any before. This time, I managed to fry TWO of them. Yes, I damaged two Arduinos before I realised there was a wrong connection somewhere. There was a short because I wired the relay circuit wrongly and sent 12V directly to the Arduino. Not just that, I fried my laptop as well. And I had to replace the motherboard. Luckily, my new boss was very forgiving.
So after realising my mistake, everything went smoothly after that. Here is the soldered circuit. The buttons and LEDs are for testing purposes and simulate the switches for the arcade buttons.
Of course I tested the circuit on a breadboard before soldering. This was the part where I messed up.
This is my circuit diagram drawing on paper. My new boss is electronics trained as well and commented that there should not be any over lapping wires and no diagonal wires, which is good feedback.
The final stage was to put the circuit into one of those black ABS boxes. The connectors outside connect to the relay circuits, to which the LEDs and wall power supply are connected.