My day job at FIRST® is working with the team developing and maintaining all the various software components which are required for a successful season (FMS, FRC-Events, and FIRST® Robotics Competition API to name a few). During the season I am part of the remote support team helping to keep events running smoothly. But one week each season I leave HQ to serve as the FTA at an event. This is my opportunity to experience firsthand the results of our efforts. A chance to interact with students, mentors, and volunteers. How do they like the game? Did that change in the software accomplish what we intended?
One of the tools I use at an event is the FTA Notepad. This is a mobile application developed by several volunteers from the Pacific Northwest District that allows me to record problems and issues that occur during each match. I make notes about problems teams are having and then track whether they have been resolved. As the FTA, I am striving to make sure that each team has the best possible event experience. As I review the notes from my 2024 event, the Smoky Mountain Regional, I want to take the time to share some observations which I hope will improve your experience at your upcoming event(s).
Your radio:
Radios losing power were my most recorded issue.
- Mount it so the LED indicators are clearly visible (your FTA will love you for this)
- Make sure that it is powered securely from the correct source
- Make sure that that source is powered correctly and securely
- Make sure that all the power connections are secure (Is there a pattern here? Do a pull test, wiggle the wires, make sure you do not lose power)
- Make sure that the RJ-45 (Ethernet) connector is firmly seated before each match.
Your battery:
Robots losing power were my second most recorded issue.
- Make sure the Anderson connector is firmly seated each time you change your battery (you can use a zip tie to make sure the connection stays tight)
- Make sure that your battery is securely attached to the chassis of your robot (there’s that word again). A loose battery can do all sorts of damage. At a minimum it may become disconnected, at the worst it may slam into other more fragile components and connections.
- Make sure that your battery can stand up to the stresses of the competition. It may measure 12V at rest, but what happens when it is under load. How low does the voltage go? More on this in the next section.
Your swerve drive train:
Swerve drive popularity is on the rise. I saw many more robots with swerve drive this year than in the past. They can provide significant performance advantages and can also present new technical challenges.
- Make sure that your swerve drive is not “browning out” your roboRIO. A detailed discussion can be found here: roboRIO Brownout and Understanding Current Draw — FIRST Robotics Competition documentation (wpilib.org). The symptom that I see when this is happening is “jerky” robot control. The power is turning off and on, making the robot hard to control.
- Make sure that your batteries are up to the challenge(fully charged and not at the end of their lifespan).
- Make sure you set the current limits on your motor controllers to reasonable values. Setting these limits is just the beginning though. Too many motors on at the same time can still cause brownouts even with limits set. Develop a power strategy by considering which things can operate at the same time, and which items if operated together can cause an issue. You can then implement this strategy with your drivers, or enforce it in code.
One other point. If for some reason your robot becomes uncontrollable and is jammed against an immovable object with wheels spinning, please use your A-Stop or E-Stop to keep your robot from burning a hole in the carpet (again, your field crew will love you for this).
Best wishes for a successful competition!