Basic PROS offline usage?

Hi all. I’m getting a team started at a local school and for now we’re playing with a Vex EDR cortex robot and PROS. So far we can get it to compile/download/run code, but only when the USB tether is connected. Once unplugged it does nothing and the game light flashes orange. It seems it’s expecting some field-management commands… ?? As a standalone robot (without any field management), can we get this to operate without a USB tether? And if so how? Vex tech support says they have a switch for it in RobotC, but they’re not sure how it would be done in PROS.


IIRC PROS does not support standalone mode.

Haha James you beat me by mere minutes. You are correct though PROS does not support standalone mode. We require an active Vexnet connection before the code is executed.

Vexxer - Here is the cortex light documentation from vex to help you understand better what the lights mean. PROS has no control over those since the master processor on the cortex is responsible for updating them.

@Jabibi Why don’t you add support for standalone?

Oooh… well that’s a bummer. We had great hopes for it. Oh well, we’ll just pick up a couple licenses for RobotC.


Just to explain what’s happening.

The cortex is looking for a VEXnet key so it can communicate with the joystick (which also has a VEXnet key). If you are starting a team that will be competing in the VEX robotics competition, you will need to have the joystick for the driver controlled part of the match. Field control is completely separate from this, the field control system actually connects to the joystick using a cable. So, despite the fact that I would like to sell you some ROBOTC licenses, you should be able to make this work using PROS if your plan is to build a competition robot.

This feature is in our roadmap and it should be included in our upcoming release due at the end of summer.

So our intention has been to compete in FTC starting this September, but I’ve been getting the kids up to speed on how robots work, mechanical, mechanicals, motors, electrical controls, software, etc. Rather than just yap their ears off for several months, we picked up this kit for use as a training tool, and I purposely chose not to get a joystick, because I wanted them to learn how to let the robot control itself, rather than ending up making more of an RC car.

While I’m here, let me point out that I’ve been mentoring FRC teams for several years and I’ll rant about how the autonomous period needs to be larger, and increase every year. It seems most FRC teams end up building a glorified RC car because there’s not much points to be had in the short auto period. ]

Currently I’ve tasked the students with designing a robot to navigate a maze, then I’ll add having them find and retrieve an object from the maze.

I’m considering doing the VEX robotics competition also, but need to research dates, etc.


@Vexxer, I had the same thought as you and want standalone capabilities for PROS. Based on the kernel code, I have a hunch it’s a simple flag that could be raised in


(we would first need to add that function to the end user API).