Vexnet Joystick Stuff

Vexnet upgrade compatibility with vexnet joystick

The Vexnet joystick is not compatible with the Vexnet upgrade kit, it can only be used with the CORTEX.  This is really unfortunate… they did not think out the upgrade kit very well.   It is also discontinued anyway.

Simple Vexnet joystick rechargeable 9.6v battery adapter:

The Vexnet joystick uses 6 AAA batteries which is very inconvenient to teams since they will have to invest in AAA rechargeables if they don’t want a to spend a fortune on batteries.

Video of adapter here.

I made a simple adapter that connects to the 75mhz controller 9.6 battery.  This is within the voltage limits of the Vexnet joystick.   Use two dead AAA batteries.  Solder a red wire to the positive end of one battery and a black wire to the negative end of the other battery.  Then connect an RC battery male to the other end of the wires.  The male terminal can be purchased from ALL ELECTRONICS for 75 cents.   Now simply insert the two batteries into the top two slots with the negative wire on one battery touching the left spring and the positive wire on the other battery touching the right pad.      In other words, if you opened the back and exposed the battery holder its like putting only two batteries in series into the top slots.  Make sure the wires are on the outer edges of the rack with the negative wire on the left and the positive wire on the right.    The two wires are then fed through a slot opening near the USB connector slot.  That’s it and it works fine.

You can then Velcro the battery to the bottom of the joystick or just use a rubber band to hold it.

10/9/2010 Update: To keep from interferring with  the USB connector  be sure to use  shielded stranded wire of small gauge that is no wider than pwm wire.    Smaller is better.   Then feed the wire through the screw hole with a wire on each side of the screw as shown in the pictures.

Then tighten the screw just enough to hold the back plate on and not damage the wires.


Vexnet Joystick vs legacy joystick:

The ability to command a pure y-axis without some x-axis slop is a lot harder with the Vexnet joystick.  Although you get a few more buttons … I would take the legacy over the Vexnet any day for controllability and the ability to trim the channels.  The slop is especially noticeable with Arcade drive.  The $150 price doesn’t buy you much quality.

10/9/2010 Update:  Note that the legacy and the Vexnet joysticks cannot be mixed.


4 Responses to Vexnet Joystick Stuff

  1. Paul Copioli says:

    Regarding the VEXnet joystick posts:

    – The VEXnet upgrade was only meant to be a temporary solution for VEXnet to make sure there was enough practical user usage for embedded wifi. It was never meant to be a permanent solution. We made a conscious decision to not support the old transmitter + VEXnet upgrade using cortex. The firmware required to handle the specific portions of 802.11g that we are using is different for the cortex+joystick than it is for VEXnet upgrade. I decided that supporting both will hinder our ability to support the nex joystick going forward. Again, this was a conscious decision.

    – On that note, we have received a few other comments regarding the joystick deadband and are looking into it.

    – Battery power. We will be coming out with something for the battery power. Most likely, it will be a wall adapter that connects directly to the program port. This allows our classroom users to drive the robots during the long school day without dealing with the battery issue. In addition, we will be coming out with a new programming cable that will also power the joystick during programming and debugging.

    – If you want to discuss these items with me in more detail, please contact me directly at my e-mail.

    Thanks for all your passion for VEX,


  2. vamfun says:

    Good to hear Vex is working the problems.

    I’m sorry that the vexnet upgrade kit was discontinued and not reworked to be Cortex compatible. You have a lot of the legacy joysticks out there and they work well. From an environmental reuse standpoint, the quality of the joystick movement/trim capability, plus the existence of 9.6 rechargeable batteries…seemed a good reason to keep them going. I guess it didn’t fit into your business model.

    I still want you guys to make a nice 9.6 v adapter for the vexnet joy sticks. Maybe have it go through the programming port as well and perhaps have a little plastic adapter that neatly supports the battery on the bottom of the joystick.

    I wonder if a standard 9v battery which is smaller would have sufficient life to power through a competition. That would be easy to adapt to the programming port.

    During most of my development of the Bobcat I ran tethered which is a nice feature since it powers the joystick from the robot battery. This, of course, is a little less practical once the team gets to full field development.

  3. Jon Thompson says:

    I am trying to build the battery adapter. I have soldered wires to old aaa batteries. I can get the wires out the hole by the usb port. But I can’t get the VEXnet USB Adapter Key past/over the wires. How did you do it? Did you use special wire?


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: