Pressure sensitive, fading leds (PSP)

[in_ducktape_armor]

  ok, so i've got this idea. i want to put Pressure sensitive, fading leds in my psp under all my buttons, but don't know how to go about doing it , can someone help me out?

[j.s2ghetto]

that could work wit the fader and wiring up the buttons some how so when u press it that one lights up but idk if u could just wire to the button itself or need to add something
and it wouldn't fade the way u want it i think it would fade depending on how long u hold it but i think u want it to fade even if u let it go like push fade starts let go fade keeps going till it completely finishes

[bustinthejustin]

Hmmm Ghetto is on to something. I think he's right. There are pinouts to all the positive signal points on the buttons (or is it ground? Idk I have no clue, not much electronics knowledge...). You'd probably need two faders for each individual trigger. Then, you wire up the positive of the fader to your R/L trigger, and then ground it. Then whenever you press the trigger, it'll start fading. When you let go, it'd stop. I don't know how you would wire it up to make it keep going, and I don't even know if my wiring idea would work O_O

[Alien_X]

A PIC would be best.

And bustinthejustin, you have the wiring the wrong way round, buttons are active low.

[in_ducktape_armor]

that could work wit the fader and wiring up the buttons some how so when u press it that one lights up but idk if u could just wire to the button itself or need to add something
and it wouldn't fade the way u want it i think it would fade depending on how long u hold it but i think u want it to fade even if u let it go like push fade starts let go fade keeps going till it completely finishes

yeah, that's exactly what i'm talking about. idk, maybe pushing the button would build up a charge in a capacitor, and then the capacitor would redistribute it to led and slowly fade out depending on how long you pushed it for, i think this would also make it fade in which i'm more than fine with. just an idea (let me remind you all that im total noob). i attempted to draw a (very) basic idea of the concept in paint.



eh?

[pm666drummer]

A PIC would be best.

Definitely what I was thinking. Or possibly if there is a regular IC you might be able to use that; haven't seen a fader IC mainly since most people want to change the 'pulse' rate

[Alien_X]

yeah, that's exactly what i'm talking about. idk, maybe pushing the button would build up a charge in a capacitor, and then the capacitor would redistribute it to led and slowly fade out depending on how long you pushed it for, i think this would also make it fade in which i'm more than fine with. just an idea (let me remind you all that im total noob). i attempted to draw a (very) basic idea of the concept in paint.



eh?

Sorry that wouldn't work, you could wire the led's ground to the button though.

[in_ducktape_armor]

Sorry that wouldn't work, you could wire the led's ground to the button though.

what?

[bustinthejustin]

Wait, so the button points are the button's ground? Meaning if I were to wire up an led to any positive point, and used the button point as ground, it would light up whenever I press the button? I still don't understand buttons   

[j.s2ghetto]

NO the buttons share a ground u would have to use a pic to detect when u press it or something like that i am not an expert on it but i kno that it won't work the way u wanna do it
buttons share gnd but have different + points

[Alien_X]

Wait, so the button points are the button's ground? Meaning if I were to wire up an led to any positive point, and used the button point as ground, it would light up whenever I press the button? I still don't understand buttons   

Yup just like that, ignore js2ghetto he is wrong - the buttons are active low!!(  ).


See this image I made several months ago:

[bustinthejustin]

Okay that's pretty cool, thanks.

[in_ducktape_armor]

Yup just like that, ignore js2ghetto he is wrong - the buttons are active low!!(  ).


See this image I made several months ago:

very helpful thnx.

[in_ducktape_armor]

I GOT IT!!! 
my uncle gave me some help.
close LED and Capacitor in parallel. the value of the capacitor will effect the speed of discharge. google "RC time constant" to find the equation.
next from what i was reading when you press the button it sends a positive voltage out to a pin.
depending on the voltage this might be enough to power the led if not I'd have to put in a transistor to "switch" on another circuit to power the led from the battery

[Alien_X]

For goodness sake!!!

Why over complicate it?

Just wire the ground of your leds to the buttons, and the positive to the pulse board.


But it is very good that you know what a capacitor is, that majority of people on here don't 

Anyway, BUTTONS!!!!

The individual button signal pin is an input to a microcontroller. This signal is brought high by the use of a pull up resistor.
When the button is pressed it connects the microcontroller's input pin straight to ground, bypassing the (around 10k) pull up resistor ( we all know electrons take the path of least resistance).

So if you were to read the voltage of one of the psp button signals (pins), when it was open (not pressed) the voltage would be around 2.5-5V (rough figure) and when pressed it would become low (ground voltage level - 0v - 0.8v approx.).

So if you solder the negative of an led straight to the button signal, and the positive to a positive point, when the button is pressed it will supply the ground.

This is all basic MCU logic.

This is how buttons are made to work with cpu's and microcontrollers in the most basic form, there are more advanced ways which utilize logic gates and diodes.. I am not 100 percent sure the psp works with a pull up resistor as aforementioned, since I cannot trace the signals path back to the processor entirely (Because it has multiple signal layers), but the rest is all correct.

[123sample]

I might try this, looks good XD

[bustinthejustin]

WOW Alien made sense to me! Thank you... Now I somewhat understand buttons :P

[in_ducktape_armor]

For goodness sake!!!

Why over complicate it?

Just wire the ground of your leds to the buttons, and the positive to the pulse board.


But it is very good that you know what a capacitor is, that majority of people on here don't 

Anyway, BUTTONS!!!!

The individual button signal pin is an input to a microcontroller. This signal is brought high by the use of a pull up resistor.
When the button is pressed it connects the microcontroller's input pin straight to ground, bypassing the 10k pull up resistor ( we all know electrons take the path of least resistance).

So if you were to read the voltage of one of the psp button signals (pins), when it was open (not pressed) the voltage would be around 2.5-5V (rough figure) and when pressed it would become low (ground voltage level - 0v - 0.8v approx.).

So if you solder the negative of an led straight to the button signal, and the positive to a positive point, when the button is pressed it will supply the ground.

This is all basic MCU logic.

thnx, I appreciate input from someone who knows what they're talking about.

[in_ducktape_armor]

Thanks everyone for your input, it was lt all very helpful, i now know how i will do it. 



GREEN= RESISTOR
BLUE= LED
YELLOW= CAPACITOR

[edit]

i made a mock-up, it works perfectly!

[Slim Hacker]

WOW a lot of tech talk well I understand all of this
and it is pretty awsome that you/they have figured it out in 3 little
parts
1 resistor
1 capacitor and
1 led

good job!

[LaCozTe-2028]

Yup alien did you got to electronique school or something

[in_ducktape_armor]

WOW a lot of tech talk well I understand all of this
and it is pretty awsome that you/they have figured it out in 3 little
parts
1 resistor
1 capacitor and
1 led

good job!

thnx, i'm fairly experienced with soddering so im hoping it will a go smoothly.

[LaCozTe-2028]

but with a pic its still ways better

[whuthefxk]

for this too work with 0603 LEDs, what capacitor should i use?