USB Powered Joystick

I’ve got an idea to make cable to power the Vex Joystick off a USB power bank because my team never seems to have enough AAA batteries. I’d make a USB Type A Male - RJ14 Male USB cable.
I believe the controller functions off 5V because the Programming Hardware Kit powers the controller through USB. I’d copy the VEXnet Joystick Power Adapter’s positive/negative leads and map them to the USB power wires.

Does anyone have any thoughts on this? (is it the dumbest thing you ever seen, cool idea that’ll never work, etc.)
Could someone please take a photo of the power adapter output specifications (e.g. 5V 0.2A) and the plug at the end of it (to see the pin layout)? My team doesn’t have power adapter.


Why not just use the wireless programming cable?

I guess it is very expensive and soon to become obsolete, but the newer one already powers the joystick off of usb while still allowing you to use vexnet.

Yeah, are using those, but we only have 2 (and 5 teams). It also means we have to be near a laptop (they can’t be powered off USB power banks, I’ve tried).

Our competitions are pretty relaxed so I’d like to use my homemade cables to power the joystick during official scrimmages as well. I think having the controller plugged into a laptop might be pushing the limit though (the laptop could potentially be altering the robot’s performance whereas a cable + power bank is almost definitely not).

I would just suggest buying more rechargable AAA batteries. They are pretty cheap

@tabor473 Thanks, but that’s kind of missing the point. We will probably end up buying more batteries (they’re about $2.20USD each), but I’d like to try making the cable an experiment.
Do you have any thoughts on the viablilty of the cable?

I made a couple of wall power adapters that use the programming port. There was a pinout here on the forum somewhere for that, just solder the - and +5v together with a cut USB cable. Finding a phone cable with all 6 pins is the hardest part.

Why are all 6 pins required? Is there some hardware check that needs to be spoofed? I would have thought that the only pins required would be the power pins (2 pins on the RJ12 and 2 pins on the USB).

Yeah, but I can’t remember if it’s pins 3 and 4 for power (which I doubt), which is why unless you are crimping your own end, you want to buy a cord with all 6 conductors.

For those in the future finding this thread by searching, here are the links & info I’ve found so far:
The joystick program port is the same as the PIC serial port (source).

field control technical analysis by JPearman.
competition switch diagram (a past team member made our own competition switch to save us the $$$)

The AAA batteries are a problem with the Vexnet. I loved being able to use the 9.6 Volt battery on the original Vex 6-channel remote.

BTW, it is possible to power the controller off a 7.2V battery. I got AAA sized metal and popped them into the joystick’s battery slot. It worked but I kept leaving the battery on the table and walking off with the controller still attached. It also really heavy :stuck_out_tongue:

Why not just use this.

Because I’d like it to be portable.

And no, I don’t want to drag an extension cord around behind me :smiley:

Are you asking to cut the adapter, solder it to a USB,male/A connector, then carry around a USB battery pack? You should also be able to charge your joystick anywhere by connecting your controller to a programming cable(, then connecting the USB male to a USB battery bank. Not sure if it works tho, but worth a try :wink:

Kind of, I’d buy another RJ12 connector an USB connector and wire the power cables

It doesn’t work, I tried today. The LED on the programing box lights up red and the joystick doesn’t turn on :frowning:

The VEXnet Power Adapter is rated for a 5 volt 1 ampere output. If you open the image of the adapter from the Vex store and zoom in, you can see text underneath the plug.

I did bring up this idea with my team at one point, but the idea was dismissed as we literally have a box of rechargeable AAA batteries, more programming cables than we need, and (unopened) VEXnet Power Adapters.
Personally I think its a great idea and would love to see someone make a working unit, even if V5 is coming next year.

I just make it a happen before the season to invest in over a 100 triple A batteries. Never went through all of them in a season.

@5YNAP5E thanks, I did try zooming in before but I thought it was too blurry… Idk why because I can’t see it fine now :stuck_out_tongue:

@OscarNVCC I just want to make it to see if I can :smiley: I know there are more practical ways to power the joystick.

So I just thought I’d say that I did successfully make the USB/RJ14 cable, and it works reliably.

Pin1 is the left most pin when the pins are facing up and away from you
Pin2: 5V out
Pin4: Ground

I also made a autonomous plug which activates autonomous (surprise!) when it’s plugged in.

To make it join pins 1, 2, 4 & 7 together from an Ethernet cable.
Circuit diagram