Im almost done with my homade dreamcast arcade stick. the joystick works and the x,b,a,y buttons work also, But im having a problem with the shoulder button's each have three wires " gnd2 ra1 3v2 and gnd3 la1 3v3" the ground is green the other colors are yellow and orange. If i hook them up like a regular push button with the ground on the bottom and one of the colors on the next post they dont work.. but if i replace the ground with one of the other two wires " so instead of having a ground wire on one of the posts i now just have the orange and yellow wires on" It will work but it will be VERY spratic......The left button should be a taunt and the right should be a light kick...... So when i mean spratic i mean if i press the left button i will do both attacks the taunt and the kick, sometimes multiple times when i only press the button once. I am using the quantum fighter pad and i made sure it worked before taking it apart. I need some help......seriously
triggers are analog buttons. The process of which should be understood to find a way to deal with it.
The grounds do what you expect, it's allows the circuit to be completed. The two wires with currents do two different things...
one creates an electromagnetic force in the trigger, the other is an induction coil with a magnetic field inside of a small pad. As the trigger is pulled the pad is squashed and the magnet gets closer to the coil. The magnet, via induction, alters the magnetic field of the coil. This change can be interpreted as how strong you are pushing the trigger.
You should also understand it works basically the same way as the analog stick. Where as the effect on the magnet is received as an x and y value (thinking of it as an analog stick)... meaning both triggers are interpreted as the SAME button. Just one is considered in the x direction and the other in the y direction.
<1,0> = left trigger pulled full
<0,1> = right trigger pulled full
<1,0.5> = left pulled full, right pulled half
You hook up that wire and send full voltage with no induction and what happens?
<5,5> = both triggers pulled really freaking hard and repeatedly... basically... due to the lack of an induction coil the current doesn't perform it's normal cycle so the chip interprets it as multiple pulls of the trigger sometimes.
answer to your problem:
get a meter, check the impedence and all the good info you can get from the returning current of the line when the trigger is fully pulled. You aren't concerned about analog controls in a fighter really, you just need "pushed or not" so you just need the trigger to fire 0 or 1, no in betweens. So use a resistor to pass the proper amount through the wire when the button is pushed.
You also have other options. Some usually get more complex, like using a hex inverter to allow the a button control both the a and c buttons. It's basically the same idea behind the Genesis 6 button pad. The Genesis technically can't support 6 button controls, so instead it used an inverter chip to know if you're hitting "A low" or "A high / X". Hence the necessity for the "mode" button to bypass the inverter and turn off the 6 button controls.
Of course constructing something like this takes knowledge AND much more money they a few handy resistors at 10 cents a pop.
Last edited by lordofduct on Sun Aug 24, 2008 11:04 am, edited 1 time in total.
Are using a first party Dreamcast controller? If so, even if you get the trigger buttons working correctly on your joystick, they have been proven to lag. Meaning, the action onscreen does not happen immediately when you hit the button. The lag is very small but it is enough to throw off your timing.
each have three wires " gnd2 ra1 3v2 and gnd3 la1 3v3" the ground is green the other colors are yellow and orange. If i hook them up like a regular push button with the ground on the bottom and one of the colors on the next post they dont work.. but if i replace the ground with one of the other two wires " so instead of having a ground wire on one of the posts i now just have the orange and yellow wires on" It will work but it will be VERY spratic......The left button should be a taunt and the right should be a light kick...... So when i mean spratic i mean if i press the left button i will do both attacks the taunt and the kick, sometimes multiple times when i only press the button once. I am using the quantum fighter pad and i made sure it worked before taking it apart. I need some help......seriously 
and does anybody already know what resistors i need to make this work Im not sure how to check the returning current