How are matches started at tournaments (using crystal)?

We’re using the Competition Template in EasyC to program our Autonomous commands and our Operator Controlled settings. No setting has been changed regarding the number of seconds each part lasts.

  1. Once we upload the program to our robot, should the robot be ready to go for a tournament?

We’ll use crystal-based transmitters since we don’t have VexNet. If I understand correctly, we remove our crystals for the tournament to avoid interference. I know we can tether our 'bots to practice, but I don’t understand how our transmitters communicate with our robot during the matches.

  1. How are (crystal) transmitters set up to run their robots at tournaments?

We want to clarify this, especially to avoid surprises, since we have our first tournament this weekend. We don’t know fully what to expect regarding how matches begin. At school, we just turn our robot on, and then turn on our transmitter to start the Autonomous portion. After the allotted Autonomous time, we gain driver control. Hopefully, the tournament matches will be little different!

1). You remove your own crystals from the robot, and are not supposed to use them at all during the competition. when you get to the field, you are given tournament crystals by the field staff. It is a good idea to check the crystal set you get given, and make sure both the numbers are the same, as occasionally you are might be given crystals that don’t match up.

2). You don’t need to change anything with your setup. When you get to the field, you plug in a cable to the teacher slot at the back of your cable. You turn on both your robot and transmitter. The tournament control is disables your transmitter from sending a signal via the cable. To start autonomous, it enables your control briefly, so that your robot starts autonomous, and then re-disables your controller so that it does not go into driver controlled period. After the autonomous scores have been counted, your control is re-enabled for the two minutes, after which it is then disabled again to stop the robot after two minutes.

read this link, its got lots of other useful information about competitions in general, seeing as this is your first one. Good Luck:)

https://vexforum.com/wiki//t/answered-vex-controller-io/12375/1

The field control turns the transmitter on and off. So the cycle is:

  1. Plug into field control, power the transmitter up.
  2. Field control disables the transmiter output.
  3. Turn on the robot, it won’t see the transmitter, the reciever light will be out
  4. Auto mode starts, the field enables transmitter output. The reciever sees the transmitter output, drops into auto mode code in the template.
  5. Code runs for either the amount of time specified in the code template OR until the field control disables the transmitter output.
  6. Judges score the round
  7. Driver mode starts, the field enables transmitter output. The reciever sees the transmitter output, drops into the driver code into the template.
  8. Code runs for either the amount of time specified in the code template OR until the field control disables the transmitter output. (*)
  9. Judges score the match.

If for some reason you think there is a field glitch, unplug your transmitter from the field. The default is enabled transmitter output, unplugging it will allow you to drive (assuming a field fault)

(*) Sometimes the field will be enabled before the ref says GO. That time is being counted down by the template. So the time may expire BEFORE the end of the match. We have added 20 seconds to the template time to account for that.

Good luck this weekend, post back how your first match went!

It’s even documented: http://content.vexrobotics.com/docs/vex-round-up/VEX-Round-Up-Robot-Start-Up-Sequence-2010-082410.pdf at https://vexforum.com/wiki/index.php/Event_Management

Thanks for all the help. We had a fantastic day at our first tournament.

We had trouble with our transmitter and receiver the first two rounds and performed poorly. After fixing the problem by replacing the receiver (whew!) we had two strong rounds, placing us in the middle of the pack after qualifying rounds.

In eliminations, our alliance won quarter- and semi-finals, making it to finals! Then each of our alliance robots faced some mechanical issue and we lost to a stronger trio.

Fortunately we left with the Judges award.

An amazing day for our first tournament! We appreciate all your help.