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FIRST Global Technical FAQ

Do you have a question about the FIRST Global Kit, its parts, or how something works? Please take a look at our list of frequently asked questions about the kit of parts. If your question isn't answered below, please send us an email:

Control System & Electrical

  • Check Electrical connections RS485 (3pin communication cable) and XT30 power connection are in place. There should be a blue light on the expansion hub.
  • Make sure you have updated or created a new configuration on the driver station tablet that includes the expansion hub.

SRS ProgrammerThe REV Smart Robot Servo is both a continuous rotation mode and standard angular mode servo. You can easily change modes using the SRS Programmer from your kit of parts (pictured).

  1. Plug in the servo and turn on the SRS Programmer.
  2. Move the switch to the S position (Servo Mode).
  3. Press the PROGRAM button.
  4. The LEDs will flash indicating that the servo has been reconfigured.

Changing to Continuous Mode from Servo mode follows the same process with the switch in the C position.

There are many more features available with the Smart Robot Servo. For more information please take a look at both the Smart Robot Servo User's Manual and SRS Programmer User's Manual.


Make sure that the motors and servos are labelled correctly in the configuration file, with the correct ports assigned and that the names given in the configuration file match what is being used in the program.

This error can occur if the OpMode is uninterruptible. When creating loops in your code, especially while loops, be sure the conditional statement can be interrupted. An easy way to do this is to do this in Java is to use opModeIsActive() in your conditional statement.

Also, never block or delay for too long in an iterative OpMode, the SDK has a 2.5s watchdog safety timer. If it thinks the OpMode is unresponsive, it will stop running as a fail-safe.


To connect the ends of the polycord/round belt, you can use one of the included polycord barbs. The barbs allow you to connect the ends of the polycord by putting one end of the barb into one end of the polycord, and then doing the same with the remaining ends of the barb/cord.

To aid in this process (because it can be a fairly tight fit), placing the ends of the polycord in hot or boiling water for a few minutes can loosen up the polycord and make it easier to get the barb in.

288 counts per revolution of the output bushing.

The internal encoder to the Core Hex Motor has 4 counts per revolution. Applying the internal gear ratio (72:1) gives 288 counts per revolution at the output.