Ask HN: Non-programmers – what are the first principles in your profession?
I am exploring a few areas (like electricity , home building etc) and was curious to know the first principles of the profession you are in or the area of study you did.
Random embedded systems stuff typed in mobile:
First principle of electricity(from an embedded systems guy), it flows like water in a loop. That might not be fully correct but it's close enough for mostpractical purposes.
You can wiggle it back and forth in a straight line though, like you would in an antenna, but not a lot without lots of power behind it. This is mostly about self capacitance, it's like having two balloons on either end of a hose, you can squish it back and forth but to make a real flow you need loops. And the metaphorical balloons are very small.
Static electricity is that same effect, you're just filling the balloon with a lot of pressure. It's high voltage DC.
The power is in the flow, like water through a turbine, rather than like in some kind of substance that gets depleted. A battery is not a tank, it's a chemical powered pump. It doesn't run out of electrons, they go from one side to the other, or around and around (I'm not actually sure about the electrochemistry), it runs of ability to keep the movement going.
Amps kill, not volts, but it's meaningless because when you know the resistance and the voltage, that is what determines the amps that will flow.
1A at 2 volts would kill you if it went through your heart, the same as a foam bat would, but it will not because it can't push through your skin with enough current(Look up thw case of the guy who died by a multimeter, he stuck both probes in his skin drunk).
But most of the time neither one kills, because we are kinda pretty OK at not touching it. What will get you is the fire it could start. And in that case it really is mostly about the amps. Low voltage might be worse, because you need more amps for the same power.
I'm software we have endless JS frameworks and new languages beginners are compelling to make. In electronics it's parts box and tool accumulating, and the invention of new unifying standards for everything.
Your new RJ45 based serial standard is great. Actually no it isn't. Just use DMX, unless you cm accept that it's not gonna be that practical to do your new thing. Treat it like software. If you do anything nonstandard, accept that it might have to be a just for fun thing that's not practical and don't dump months unless you're really sure.
Or at least, that's what confused me as a kid and absolute beginner, not sure if its the ideal starting point.
The first principal of actually doing low budget embedded systems for companies who have never made a PCB or done VCS is in my opinion, don't be a liability. Forget about providing value, that comes after you've made sure you aren't delivering overcomplicated crap only you can maintain, that will be bad for the company and also your sanity.
An Amazon relay module and an Arduino, powered via a 12v to USB adapter, is unprofessional as heck, but it works and if it doesn't it's rather obvious what to do, and I'd rather see it than any one off PCB you had made at oshpark then left the company. And a random outlet timer off the shelf is probably even better.
Now if you're doing anything artistic your job is to not mess up the theme. If you're doing some creative work, keep the chiptune out of the medival fantasy installation. Don't use some unnatural color that's not historical nor part of any cinematic language for that.
With safety or equipment critical things the first rule is I don't trust you, and you shouldn't trust me. Actually prove it's safe with numbers, not ideas.
The part has a spec for a reason. I have no education on whether it's safe outside the range, just that you're supposed to stay well within it. I had no reason to learn about that. It's not a thing. Engineers want it to stay not a thing. I will not be happy if your 100mW laser is near children's eyes and I don't care if you think it's fine. Please don't.