X1 X2 Analog Input

Filippo Gibellini · Sep 13, 2023

Hi, I'm an electronics engeneer. After carefully reading the instructions file https://compass-ssl.xbox.com/assets...df?n=Xbox-Adaptive-Controller-technical-input-spec.pdf I tried to make my first potentiometric analog joystick (2 axes, 2x10k potentiometers). After making the connections shown in the specifications, I connected the joystick to the XAC. However, after launching the configuration program, I noticed that the device does not work properly. I also tried to insert an active circuit (based on op amps) but it didn't solve the problem. I tried to detect the voltages but the operation is not clear: not having the internal electrical diagram of the XAC I cannot understand its behavior.

This is the joystick I used https://docs.rs-online.com/2dff/0900766b803d068c.pdf.

Do I need to use specific joysticks?

Can anyone help me solve the problem?

Thank you

:)

Filippo Gibellini

I measured approximately 1.25V on the voltage reference

Filippo Gibellini

if I connect 2 independent trimmers (or potentiometers) to the 3.5mm jack they seem to work correctly

SwordofWhedon

i'm afraid this is not the right forum for that, this is a general consumer technical support for him, and not a place for electrical engineers to compare notes unfortunately, no one here has the knowledge to answer your question

I can tell you that commercial joysticks have to be whitelisted if they use USB, which you're not.

I suggest you look on forums like or Ben Heck's community for better input

https://support.xbox.com/en-US/help...ility/xac-user-guide-using-external-joysticks

https://community.element14.com/challenges-projects/element14-presents/benheck/f/forum

MtnBuffalo

Hi Ezra,

thank you for your thorough answer. I won't tinker with the XAC hardware to alter the resistor range - that would also void the warranty of the device.

According to the XAC information found here (link), input ports X1, X2, LT and RT all accept analog inputs. X1 and
X2 is mapped to forward/backward as default. The analog feature of X1 and X2 may therefore come in handy for some games so the user doesn't have to use e.g. a joystick for in-game movement.

I will contact StealthSwitch for information regarding their hardware. But as I found during my tests, the analog ports need a potentiomer in the 200kΩ range to get full throw. However, StealthSwitch may have
an option for arcade buttons as a foot pedal cannot be used for the setup I´m builiding.

I still have one question: Do you know if the resitor range of the analog input ports is something that may be altered using e.g. a firmware update or similar in the future to accommodate different types of external hardware? This would be handy for the
arcade buttons I've described previsouly as this commodity hardware is very cheap (6 $/button) in comparison to e.g. hardware from StealthSwitch.

Thanks for helping out

Aiobhann

Updating for anyone else who might end up with this problem:

After further testing and trying things out, I've found the XAC X1/X2 slots give random, constant joystick output when you plug in a cable that's not attached to something that's programmed as a joystick.

In effect, if you just plug in a working cable, a working cable attached to a working button, or a working cable attached to a not working joystick, it will appear to "spin" in games.

One of my joysticks had a tight connection. I have reduced hand strength, so I didn't realize the cable wasn't completely pushed in until I managed it by accident. Once the cable was pushed fully into the joystick, the spinning stopped.

My second joystick appears to be dead. Even after having someone else make sure the cable was pushed in all the way, it still "spins" aka, doesn't pick up.

X1 X2 Analog Input