Explanation of SifuF's volume control diagram

[Tchay]

I noticed that a lot of people were scared and confused by this diagram. No need to be !!!

(lol I have never posted in the N64 section....wierd)

Oh, and I realize this is very random, but its 3am so what else am I ganna do?

Essentially, you are looking at the building blocks of the electronic world. What you see in the picture below are "logic gates." The half circle is an AND gate. In noob terms, the AND only allows voltage to flow through it if both inputs are activated.

Keep in mind: these are symbols not physical drawings of gates. All you need to know is that these gates are inside of IC chips - that is how you will use them.



Thus, pushing "start" AND the "up" button will allow voltage to go to the "volume up" area. "Start" AND the "down" button will allow voltage to go to the "volume down" area.

The triangle with a circle on the end is a NOT gate. It reverses the high/low flowage. In noob terms: this gate makes sure that voltage will go to the AND gate. Why do you need it? Because when you push the "start" and "up" button, you are connecting ground to the AND gate.

AND gates don't like ground very much. In fact, they hate ground so much that no voltage will pass through the AND gate unless both of their inputs are "high" (basically not ground). So the NOT gate turns that ground into a voltage signal (high) that can then pass through the AND gate.

Check a few posts after this one for info on the NPN logic. Credits to Erlex!

SifuF was also kind enough to give us the names of the IC chips that peform AND and NOT functions.

Here's what is going on inside of an AND IC chip. This picture is what allowed me to understand this crap:


These chips are EXTREMELY helpful even though they are kinda basic compared to billion transistor chips. But these chips can give you a lot of cool ways to program your portable. Volume control, as seen above, is a great example. Think about when you use SNES emulators on a PSP. You have to press several buttons to get to the menu. That is AND gates in action.


- If you were really crazy, you could even program your portable to switch between battery and power cord at the press of a button (although that would require plugging in the power cord before hand)
- OR you could program the fan in your portable to shut off to save power (you would have to live in either Canada or Wisconsin for this mod )
- program a switch between PS1 screen and TV screen
- program a switch between gaming platforms if your portable was multi-platform
- program a reset button combo (ex: start+Dpad left+L = reset system)
- screen brightness

You get the idea! So gates are cool, no need to think of them as "too much work". I mean we portablize so even AP exams aren't too bad these days

okay I'm going to bed now...

[Squidlekins]

This is fan-freaking-tastic... and so simple even I can understand it. Way to go SifuF, you continue to inspire.

[mako321]

since I am a failing noob, EXPLAIN.

[blaze3927]

^^:facepalm: i hope that was a joke

i would give you a free thumbs up for this excellent job but there aint no emoticon

[Erlex]

Good work on explaining some basic circuit theory. As stated, a lot are turned off by it when it isn't nearly as hard as it looks.

The NPN - 2N3904 is the type of discrete transistor that he used. This one works by passing a signal from the collector, to the emitter when the base is high (can be thought as on/when voltage is applied/binary 1). See picture.

I don't want to high jack your explanation or anything, but here is a visual explanation of pretty much what Tchay said. This is for the case up turning the volume UP. Remember, the diagram is a logic diagram, the symbols are not physical components.

This is when no button is pressed.


This is when the start button and the up button are pressed.


Maybe that will make it a little more clear

EDIT: Fixed my silly logic mistake.

[kibble]

Erlex, you might wanna check your colors there. You're using red for the start and up buttons when pressed, the ground would be considered a logic 0. Also, the NPN transistor at the end pulls the line down to ground, so it should be blue instead of red also.

[Erlex]

Oops. I confused myself I guess. Thanks kibble. Ill fix it.

[Tchay]

Thanks for helping me out there Erlex! So I guess I was kinda right about the discrete transistor: it allows voltage (high) to flow to the volume control (up/down) only if a voltage goes into it. Otherwise it connects to ground.

[MarioOwnsAll]

This is just like the binary math I am studying at BCIT thanks for the pics man.

[Triton]

Yep! boolean algebra is basically just the math side to digital logic.