VEXNet upgrade

With the VEXNet upgrade for the pic microcontroller do you require easyC V4 for the cortex or do you have to still use PIC programming? Also with the VEXNet upgrade for the PIC transmitter, can you attach a cortex partner joystick as a partner or does it still need to be a PIC transmitter as the partner?

You use easyC V2 and VEX no longer has this in stock.

I do not have easyC, but I would assume you’d still use the PIC version. The programming languages are dependent on the hardware of the controller, not on how the transmitter connects to the PIC.

You cannot attach a Cortex joystick to a PIC transmitter. (even if it has the VEXnet upgrade.)

thanks for the help. Also I am aware that the website and the company says they have none in stock however one of their resellers that are near me has them in stock.

According to the VEXnet Upgrade page, you need easyC V2 or easyC Pro OR if you use RobotC, ROBOTC for IFI VEX 1.98.4.

Newer version of EasyC v2 and v3 ( Pro ) and RobotC should be fine as well…

BTW, which Retailer has the VEXnet Upgrades?? is showing that they have them in stock and they are added to your cart if you add them.

Thanks for the link… I should get a backup.

one other thing. I would asume you can but can you link a vexnet transmitter module to a cortex or does it need to connect to a pic vexnet upgrade module.

VEX does not support that (it may or may not actually work), and also it is illegal for VRC competitions:

yes i am aware of this however I am not competeing with the official vex league. My school board has started they’re own league. Last year we competed in swept away and this year we are doing elevation. We have only competed in the clean sweep and round up season with the official vex league.

I was able to Link the VEXnet transmitter module for the 75Mhz Controller to a Cortex and Link the VEXnet Joystick to the VEXnet PIC module, BUT I DID NOT try and see if the OI would control the Robot…

I would guess that there may be a Similar Command Structure, and it would Partially Work…

It was discussed previously here: (scroll down to JVN’s post at the bottom of the first page).

In short, at the time it appeared to partially work, but VEX does not support that usage and couldn’t guarantee that it would continue to work. Firmware upgrades since that post may have already broken it.

I certainly wouldn’t buy any equipment with that usage in mind.

Thanks for the Link… My Forum Reading for 2010 was very Spotty… :wink:

It is kind of Sad, because I like the Control Sticks on the 75Mhz Transmitters better than the Game Controller style Control Sticks…

It would really be nice to Mix and Match systems as needed…

It should be possible to construct an adapter that lets you plug an old 75MHz transmitter into the partner port of a VEXnet joystick and at least use it as a secondary control. You’d need a microcontroller between them to handle the protocol conversion, but both protocols are well documented.

You could do this with a disused Vex PIC Micro (there is MPLAB code here for decoding the old PPM signal), or pick up one of the many tiny Arduino variants for something small enough to put in-line covered in heat shrink.

[EDIT] Actually, the code link above is for PIC code to generate PPM signals. Decoding them is easy on the PIC microcontroller because it has two built-in ports to read PPM signals :wink: Then it is just a matter of a simple program to post the control values via the serial port using the VEXnet Partner Joystick protocol. I think you could use the serial half of the orange programming cable as a level shifter - you just need a DE9M to 4P4C modular adapter to connect the programming cable to the partner joystick port.[/EDIT]


  • Dean

I did think of this… I doubt it would be VRC Legal, but maybe it could be designed and submitted to the VEX Engineers as User Designed Hardware…

I would think that some teams might like the Option to the Old Control System…

There was a post from VEX a few weeks ago that said any user created electronics could be connected to the partner port on the VEXnet joystick. One of the college teams was thinking of hooking up a USB arcade style joystick, they may have done this I haven’t heard, the difficulty being the USB connection to the joystick rather then the partner port interface.

For 75MHz receiver support, according to my notes from last summer, the Rx1 port on the cortex goes to Port C bit 8, the rx2 goes to Port B bit 10, so if support has been dropped from EasyC we could add it back in with custom user code, however, I have a feeling it is still there.