Madcatz xbox360 LT/RT help

Tech Talk
21

Trigger pots should be removed. Also, have the power and the ground for the inverter coming from the +5v and ground from the USB cable.

22

That’s the way I have it wired up. Pots gone +5v and ground from USB for the chip.

23

Huh. The only reason I can think of for the analog stick(s) to move when the trigger is pressed is if the voltage on the analog pots changes from a change in voltage in any of three pins. Can you check the voltage on the high pad of one of the potentiometers when its plugged in? If it’s 3.3ish volts, maybe move the inverter power over to the high pad of the pot? (I’m wondering if the board is seeing 5v on the trigger and thinking that the high voltage for all of the analogs should be 5v when its not)

24

Voltage at the Joystick pots is 3.26. I moved the voltage line to the trigger high side. Now everything is rock solid. Thanks Toodles, you da man.

Michael

25

That’s weird, but glad it worked. I’ll edit my original post on the inverter.

26

Here is a diagram for this circuit.

27

I see from this post above that newer versions of the gamestop branded 4716s require this more extensive trigger work. I just picked up a new 4716 and I was wondering if there was a quick way with a multimeter for me to tell if the triggers are active high or active low? Would just be easier to know if I need to pick up the NPN transistors before I head out to Radio Shack to pick up my supplies.

28

If you open it up and the pcb looks like the following photo, you have the older(easier) pcb…
http://picasaweb.google.com/wliu0912/PrehackedPads#5282843023799314882

If you open it up and the pcb looks like the following photo, you have the newer(harder) pcb…
http://picasaweb.google.com/wliu0912/PrehackedPads#5275066499737886146

29

Anyone have a photo of how the setup using the chip would look?

30

Thanks for the pics zombie cpt. Just what I needed.

31

My apologies if I’m misunderstanding the progression of this thread, but is the diagram the same as Toodles’ previous post referring to this method as “this way requires two resistors and one chip”? I’m asking because I followed the diagram for the late model Madcatz and having trouble with it (no response at all, but no misbehaviour either).

I’m just hoping I’m having a comprehension error before I go back and tear it apart looking for loose ends. ^^;

32

Whoa, I should have actually looked at that diagram earlier; the placement of the resistors is wrong. The resistors shown bridging the High and Wiper lines of the trigger pots can be removed; they aren’t needed when using the chip. The other two resistors are shown bridging the exact same things, the Wiper and High lines of the trigger pots; this won’t do anything.

Get rid of the two resistors on the pots; they aren’t needed even if the pot itself is removed because the chip will force the voltage high and low. The other two resistors closer to the chip need to be bridging VCC with the inputs, not the outputs. They should be going between the VCC line and the wire going to the button.

33

Wow, I knew you were all over these forums but didn’t expect that quick a response. :slight_smile:

Is the diagram otherwise fine? I noticed your earlier post had the signals on the “odd” pins and wipers on the “evens”. Does that not matter so long as they’re correctly paired?

34

Damn, good catch. Yes, the inputs and outputs are backwards on the image as well. The grounds look to be properly connected to the inputs.

35

Brilliant, thanks for clearing that up! I won’t be able to fix it until tomorrow but I’ll be sure to post an update.

36

I’m busy procrastinated homework so I cranked this out. Sorry for the hackish MS Paint.
http://img88.imageshack.us/img88/9387/cgtriggeryw9.png

Hope it helps, but some folks get uncomfortable when I do schematics.

37

That makes sense to me, thanks Toodles. Any tips on B&M stores you can pick up the needed parts at now that Radio Shack only sells cellphones and batteries? I’m hoping to have this pad installed in the next few days.

38

Radio Shack might have the chip, but they will almost certainly have the transistors and resistors in the sliding door cabinet they’ve scrunched the old glory of RS into in the back.
Only other chain I can think of is Fry’s. Outside of those, either local stores in your yellow pages, or ordering online.

39

Thanks for all the help again, Toodles. Mine’s not quite as elegant as yours since I didn’t want to touch the board again and just rewired a few things from the erroneous diagram, but it’s working beautifully. You’re a gentleman and a scholar, and I hope this thread manages to stay near the top for everyone picking up current Madcatz pads!

40

One thing to add is that if you are not planning on using the RT/LT, you can leave the pots on. Turn them so they are in the “off” position and hot glue them down. Save the trouble of doing extra wiring work, again only if you never plan to use those buttons.