VEX Joystick Accelerometer; Question and Concern

Hi,
I have just spent the past few hours looking up low pass and high pass filters as well as every other method I discovered about reducing and/or removing the excessive “noise” that the VEX Joystick Accelerometer outputs. When connected via VEXnet, the values for the X and Y axis jump between 127 and -127 in what seems to be complete randomness. I attempted to simply average the values out over different periods of time with limited success. I was under the impression that this “noise” was something that was just something I was going to have to deal with until I plugged the A to A cable into both the cortex and the robot. Now, the values are all constant and don’t bounce around wildly. I again tried to see what would happen when using the VEXnet connection and the values went back to their random jumping around. I am using the newest version of RobotC to read the values. What is going on? How can I fix this? Is this a hardware problem or a software problem? Do I need to send my controller back to be fixed?

On another note about the VEX Joystick Accelerometer. The joystick webpage (http://www.vexrobotics.com/276-2192.html) still advertises the VEX Joystick as having a 3 axis accelerometer.

This is false advertising and might become a legal matter if someone chose to make it one.

Currently the VEX firmware doesn’t support the Z axis output or the shake output. I would love to see these features added but if they aren’t going to be forthcoming any time soon then I would sugest that you either mention that those features don’t work or remove them from the list.
This has been this way since 2010 at least: [https://vexforum.com/t/answered-vexnet-joystick-accelerometer/17683/1

Thanks,
Fido488](https://vexforum.com/t/answered-vexnet-joystick-accelerometer/17683/1)

) still advertises the VEX Joystick as having a 3 axis accelerometer.

This is false advertising and might become a legal matter if someone chose to make it one.

Currently the VEX firmware doesn’t support the Z axis output or the shake output. I would love to see these features added but if they aren’t going to be forthcoming any time soon then I would sugest that you either mention that those features don’t work or remove them from the list.
This has been this way since 2010 at least: [https://vexforum.com/t/answered-vexnet-joystick-accelerometer/17683/1

Thanks,
Fido488](https://vexforum.com/t/answered-vexnet-joystick-accelerometer/17683/1)

Thanks for pointing this out. The website has been corrected.

The original intent was to enable this additional functionality, but since it is not currently implemented, we will remove the description from our product page & specs.

-John

I took a look into this and, as far as I can tell at this point, it’s a ROBOTC software bug.

I found the same results you have, using ROBOTC accel X and Y are stable with the USB cable but very unstable using Wifi. I tried both versions 3.08 and 3.04 (although I did not change master firmware, too much of a PITA for now). I also tried the latest version of EasyC and it is stable under both conditions leading me to think this is specific to ROBOTC. I have a method of looking into memory for a running ROBOTC program and it looks like the data being received by the user processor from the master processor is good, that’s about as far as I can debug so I will send in a bug report to CMU.

I’ll look into this for you (it’ll get added of my large list of ‘things to do’) but it might take a while to get to it. I suggest still making a support ticket on it (that way it’ll have a visual reminder for all our staff to see). Thanks for the potential heads up, and as always let us know if you come across any problems with ROBOTC!

Thanks to you all for the info and for the help.

-Fido488