Ringmaster Programming Skills Intro Help

I am a new coach leading two brand new teams and would appreciate guidance on approaching programming skills for Ringmaster.

The teams have been trying to use basic robot commands to release the bonus tray. Example attached. The teams are struggling with:

  1. The programs are very sensitive to having the robot perfectly straight before pressing start. If the robot is not perfectly lined up, it will drift out of place while driving across the field.
  2. Even when the robot is lined up correctly, the robot does not always drive perfectly straight.


  1. Are we even on the right track here? Is there a better path for learning programming within the Ringmaster game?
  2. How can we resolve the above issues?

If there’s interest, I could facilitate a few programming skills video conferences. I have a GoToMeeting video conference subscription that supports 25 participants.

Thank you,

What type of drive do you have on the base? What type of wheels?

I went to a workshop this summer and we played around with the robots trying to get them to drop the tray while in autonomous. We found the greatest success by playing around with the speed of the wheels. Have them do trial and error and they will see some good results.

We are working with Stretch, which is the same drive as the clawbot. We have tried the regular wheels from the Stretch build guide and 2 omni wheels on the front.

We have dropped speeds down to 40 as noted in the example program. Slowing down helps some. If the robot starts just a few degrees off, it will miss the bonus tray levers after traveling the length of the field.

Last year, my kids would make it run into a wall to get it straight again before going to do a task.

You can use the gyro to help it run straight but how much this will help depends on the way in which the robot is going off course. The gyro measures change in rotational position so if it “crabs” off line, it won’t be much use. You also have the black line running all the way to the buttons which could be used as a way of keeping on track, but that also presents it’s own problems as you can’t use traditional line edge following because of the regular crossroads in the black lines.

Is there any way to have the VEX IQ robot go straight using Modkit and the gyro? I would need to see a program or code.

We wrote a nice bit of code using the color sensor. It follows the line down the field and detects the end of the field using the bump sensor. Works like a champ every time.

You could put it on the back of the robot and run in reverse.

@turbodog How do you account for the crossing line on the iq field? My son has written two different programs one runs the length takes the rings off the far post backs to the button hits the other button and then dumps rings on the pole. Then does a small turn and pushes any rings in for an extra few points. It works… sometimes. 57 points last competition.

The other does the first two posts rings to pole and again works sometimes… 70 points when it works but they haven’t ran it at competition yet.

We use a smash into the wall to straighten it out on both and that works pretty well, but I’d love to help him follow the line across rings to pole if it is “easy” to account for the cross lines.

We currently have two color sensors hooked up and have written small programs against them but nothing we have implemented in competition code yet.

The line happens to line up with the tray release lever. Start at one end, with the sensor already on the line. It should almost track down the field w/o help. You might have 1 sensor correction 2/3 the way down. Then, we watch the bump sensor. Capture that input. Stop the wheels. Do a manual push for another few inches to force the lever to flip. Then a manual reverse, turn 90, forward, watch for the line, turn 90, forward (using line tracking), and hit the other paddle.

Got it thanks.

Be sure to back up (after paddle1) a good way and stop IN THE MIDDLE OF THE ‘SQUARE’ so you wont’ accidentally hit a cross-line.

Also, this distance gives the line follower enough time/distance to get a really good alignment on the 2nd paddle.