How to never end up with an unpowered power expander during driver control

As anyone who has been to a competition knows, people are always forgetting to plug in their power expander! This often causes even the best of teams to lose important matches. But I have a solution, and it’s not even very hard to implement. The power expander has and always has had a status port to check on it’s status. The solution is to simply have your autonomous routine check if the power expander is on by checking the status port, if the power expander is on, run the autonomous routine. If not, don’t run it. This will cause your robot to never move in autonomous if your power expander isn’t plugged in. The ruling says that if your robot didn’t move in autonomous, you can plug in things or turn things on.

TL;DR: use the status port on the power expander, it’s there for a reason.

Thats a good idea. Thanks

Our team blew a undefeated day because of this.

They implemented this system and never had a problem again.

Some teams will have the speaker play a tone until it’s plugged in, which is also fairly effective.

This was my thought. We usually just plug them in when we put them on the robot. I don’t understand the issue with that.

Our team had it plugged in, just not all the way.

In our case our driver was the only person from his team there that day and made a mistake in a rush.

things happen, they still managed to win the tournament.

Not plugged in all the way… Huh, there’s a clip. Oh well, things happen.

Sometimes the first line of defense fails and other countermeasures are required.

There was serious discussion why the failure happened and from that countermeasures were set in place.

In this case i think the pins were a little funny (maybe the clip is broken, idk), it doesn’t matter. Generally operation critical systems will have multiple redundant systems to insure it remains operable. We determined that such a failure is possible and that implementing a secondary system was unobtrusive and effective. so they did it.

The whole thing was a text book example of problem solving and counter measuring. Great resume stuff.

Yeah, I am just always genuinely confused when this topic comes up because I have never had an issue. That being said, I’m sure I will lose an important match because my power expander is not plugged in.

If the wires are broken/wonky, I can entirely see something like this happening. But then, not running an autonomous routine in order to plug it in, well… It’s already plugged in, that isn’t the problem. Making a sound wouls be better, you could go get another battery in time.

it can happen to anyone. Especially if that person is doing more than they are use to, and are in a hurry, or being rushed by the field staff. Its funny what stress can do to you.

These guys went on to win state last year, so they aren’t a couple newbies, things can just go wrong.

It’s best to play it safe.

I thought of this a little while ago but never actually did it.

Let me know when you figure out a solution to accidentally downloading the wrong program :stuck_out_tongue:

Use a vex speaker, there are audio files for every number that it can play. In your code, have a number that you increment with every revision of the code, and make it so that when the robot powers on, it says that number

Make a checklist. It will eliminate mistakes like this. It doesn’t need to be complicated, just have plugging in and turning on things on it somewhere, plus make your last point 3 green lights on the controller &1 green light on the expander.

This is a great idea. Another great idea is to have a check that will check things like this and display error messages on the LCD screen. You could run this test before each match. It could even be used to check each motor and sensor.

So, what would you plug the other end of the status port into? Would it be analog? Or digital? And how do you go about programing it?

Edit: Figured out the first part with some research :expressionless:

That’s a great idea, at state last year we lost an important match because we had no power going to the lift because we forgot to plug in the battery.

We used to have the LCD display a reminder to plug it in but we didn’t think to have the code actually check