slide switches are expensive, jumpers pins are cheap, solder jumpers are free 
Just to add my $.02 to all this speculation/pondering/thinking out loud, my personal philosophy is that if we can do this through analog means then we should, so I think itās worth going with 2 7400s versus a uC.
I agree with logic over uC for this, certainly. Cheaper, faster, easier to use. Mine doesnt use those 7400s though, I went with an inverter and a nand and some pull up resistors.
Makes a lot more sense; wasnāt really thinking too hard about it, but a properly designed discrete logic circuit should be easy enough to select between the two modes (which was why I was contemplating an AVR). Definitely wouldnāt include aswitch, or even the jumpers+pins ā just design it in a flexible fashion so that itād be easy for people to add them.
Itās not just about making it a solderless solution. Thereās also the fact that something on a board is easier to mount/organize than a freestanding chip.
Thatās a good point as well, though anyone who can dead-bug this circuit could also go buy a couple dollarsā worth of perfboard to build it on. A nice board with a screw-hole or other convenient mounting feature would be significantly nicer to install cleanly, and could also reduce sizeā¦
So these workarounds are great, and they definitely make playing with an ABC better. I wouldnāt call these workarounds āidealā though, from an end user standpoint. Ideally, opposite cardinal directions would work like this:
Hold L -> Character moves left
While still holding L, press and hold R -> character moves right
Release L -> character continues moving right
While still holding R, press and hold L -> character moves left
Release R -> characters continues moving left
So basically, whenever the system receives two opposite cardinal inputs, whichever one is newest wins. The idea here is that if Iām blocking by holding Left, and I get crossed up and I start pressing Right, I want Right to come out even if I havenāt quite released Left yet. I donāt want Left, I donāt want Neutral, I want Right because thatās the button that I pushed. Iād want the same for Up and Down.
I get the feeling that implementing something like this would either be really easy or really complicated. Any thoughts?
itād be pretty easy actually, but I dont think thatād work out when you take both axises into account.
Take the hcb type motion for example. Itās common and all too easy to press:
r, r+d, r+d+l, l+d, l
Using the cleaning style youāre describing, that would translate to:
f, d/f, d/f (no change) d/b, b
hmmā¦ the way I imagine, it would translate to f, d/f, d/b, d/b, b
which is still no good, and I see your point how l+r=n would solve that. but being a marvel player Iām more concerned about blocking L\R crossups and changing dash directions quickly. I just feel that the most sensible control scheme is that āwhat you push is what comes outā. If I press right (after holding left) itās because I want right, not because I want neutral.
l+r=n would help because l+r+d=d instead of db, thus providing normal hcb input.
right, but personally Iāve never had a problem with hcb and like I said earlier, Iād rather get the direction that Iāve pushed
And what have you played on an all button controller? Because if itās SFIV then of course you wouldnāt have any issues with a half circle, but for Marvel, which requires a stricter input, or a lot of older titles, you might not hit that half circle as reliably.
Just marvel
Well then you have some good execution, but the l+r=neutral really does help out.
hrm. well seeing as Iāve been using a stickless controller for all of two weeks now, I probably ought to heed your advice. Iāll try L+R=N first and see how I like it - I figure it has to at least be better than L+R=L 
Well Iām not saying itās impossible to do a half circle without it or anything. Since I play on a PS360 I donāt have l+r=neutral on my Hit Box, but because Iāve played on it for so long I just got better at my half circle execution. That being said, you can still feel the difference, whenever Iām play testing a new box even when I half ass a half circle it still comes out, whereas on my own I have to consciously try to get the half circle.
Does anyone have any info on turning an HRAP 3 into a hitboard? Iām looking to mod mine but I can only find info on doing it to a madcatz TEā¦ or is basically the same process?
So, my friend and I tried to do the up+down=up mod last weekend, and itās safe to say it was a complete and total disaster. We bought 2 NAND ICs and neither worked - weāre afraid we probably overheated them with the soldering iron, but since my friend doesnāt have a multi-tool anymore itās hard to tell exactly whatās going on. Basically, weāre not getting any signal output at all - down is completely dead.
So I had some questions about the NAND IC:
-
If the IC has power and is properly grounded with no inputs, all gates should be outputting 1, correct? so we should be able to test by soldering VCC, Ground, and one of the gate ouputs to a button, and that button should always be on?
-
I donāt fully understand how Danās circuit works. Itās probably not important that I understand it, but Iām just curious by nature. My understanding:
The first gate inverts the Down button so that pressing it sends 0 and releasing sends 1. That means that the second gateās truth table looks something like this:
Neutral: 1 0 1
Down: 0 0 1
Up: 1 1 0
D+U: 0 1 1
which doesnāt make any sense. that leads me to believe that Iām completely missing something. I thought the purpose of the chip was to only send 1 when down is pressed without up? It seems like it would always send down except when up is pressed by itself? Isnāt the desired result something more like:
Neutral : 0
Down: 1
Up: 0
D+U: 0
My understanding is that first Up needs to be inverted, and then both connect to an AND gate (with an unfiltered Up signal also sending to the PCB). So instead of inverting down, it should be Up thatās inverted, and then the final output needs to be inverted as well. That would lead to this truth table:
Neutral: 1 0 0
Down: 1 1 1
Up: 0 0 0
Up+Down: 0 1 0
- How easy is it to fry one of these things? My friend was trying to be careful, but do we have to be super duper careful with these things? Iām thinking of buying a 14-pin socket, that would help keep it from frying right?
http://www.thegamesurgeons.com/Hrap%20panel%20replacements2.html
If you mean electronics then it is the same process. Cut the joystick wires and connect QDS to the signals and daisy the ground.
I dunno about frying and Iām not sure how much I can help with troubleshooting, but common ground PCBs detect an input as pressed when a line is grounded (0), if they have voltage on the line (1) then they donāt count an input as pressed. So yeah, you send out 1 from the 7400s if a button isnāt pressed, and 0 if it is pressed.
Up goes to the PCB all on its own since we donāt need to actually filter Up, but we do also input it into the 7400 so the circuit can detect when Up is pressed, and lock-out Down when that is happening.
edit: just to make sure weāre on the same page, youāre referring to these diagrams right?GUIDE: Preventing SOCD on any common-ground PCB by using 7400 chips
I posted some other diagrams earlier in this thread but I think it took a few for me to get it right.