usb-serial woes

I bought my classroom robotics gear in two stages. Six kits with the PICs in '08 or '09 and then six kits with the Cortex in '10 or '11. I also got 6 more Cortex controllers for the older kits. Shown below are the kinds of cables that shipped with each kind of kit. I honestly don’t know which came with which but only the type on the right works. (This actually plagued me for years and I would just troubleshoot and swap things out until we could download to the Cortex.) The fact that only six worked wasn’t an issue because I never had a class with more than six robots running at a time. Now I need to use them all. Do the these cables require different drivers? In all the documentation I have seen they distinguish between pre and post 2012 but I’m pretty sure both of these are pre 2012. I’m happy to buy third-party if that’s what it takes but thought I would try to get this other cable going first. I will be running 12 computers so it would be OK if only one cable type works with some computers and the other type with the rest. Any thoughts are appreciated.


MacBook Pro
Windows 7 Enterprise
RobotC 3.65
Vex Cortex w/VexNet


There has been some discussion a while back on these guys. Something about non-compliant chips being used in the cable making the new Prolific drivers not work. You can downgrade the drivers but it takes a lot to keep them happy.

I suggest tossing them and ordering the new style Vex programming cables if you can.

Or you could do something like this. I made a franken-cable that worked for me with a little persuasion to get the screw holders to line up. The cords are not attached solidly but it has worked just fine for 2+ years now.

So $15 from Amazon and a little elbow grease or $49 from Vex. Up to you.

If you have to buy 6 new cables, you could just get USB A male to A male cables. They’re cheaper and in our experience a little less finicky, but you don’t get wireless communication of course.

Thanks for the responses. I’ve got A-A cables for each kit that we fall back on when things aren’t working right. I didn’t realize until yesterday that you can go from controller to Cortex with the A-A, so I feel even better about it now. I will get the usb-serial adapters you suggested from Amazon as I had one lying around and it worked well.

So… I think I’m good. Amazing what you can get done after the students leave.