FIRST Tech Challenge Tech Talk: Rev Robotics Expansion Hub FAQ

Read our new technology evolution announcement here!

Q: Why the change?

A: There are several reasons for the change to the REV Robotics Expansion Hub. The new configuration will be easier for teams to use. Placement of the single REV Robotics Expansion Hub takes up less �real estate� and will give teams more options in how they build their robots. Wiring will be more straight forward with fewer connections. Also, REV Robotics Expansion Hub connectors use compact hobby-style connectors that are commonly used in the RC/hobby industry. These connectors offer greater resilience to shock and vibration. The cost of a single, integrated electronics hub is less expensive than several discrete devices. These benefits follow the similar evolution of most electronics (smaller, faster, cheaper).  

Q: How does this effect programming? 

A: This year, teams programmed in JAVA via Android Studio, App Inventor, or Blocks. 

Next year, the same languages will be allowed and teams should see little difference in their programming experience with the REV Robotics Expansion Hub. One small change will be the ease of addressing motors, sensors and servos since programmers will directly assign these values through the REV Robotics Expansion Hub and avoid the step of choosing a particular Modern Robotics device, and then assigning the values. 

Q: Can I continue to use Modern Robotics modules? 

A: Yes. Teams using Modern Robotics modules can continue to use these devices. They can expect the same performance they have been used to, and the new REV Robotics Expansion Hubs will have similar output characteristics to the Modern Robotics modules. For example, DC motor current rating is the same between the two controllers.  

Q: Can I replace my Modern Robotics devices with the REV Robotics Expansion Hub via the FIRST�storefront? 

A: Yes. Veteran teams will be allowed to purchase a maximum of one REV Robotics Expansion Hub via the FIRST� storefront at a team discount price upon registration next season. 

Q: Can my existing servos and motors/encoders be used with the new REV Robotics Expansion Hub? 

A: Yes, teams can use their existing servos and motors/encoders with the new Expansion Hub. Existing servos can be plugged right in to the Expansion Hub. The 12V power cables of existing approved motors will need an adapter cable to connect these motors to the Expansion Hub. For the existing approved motor encoders, a special adapter cable with a logic level converter will need to be used to connect these encoders to the Expansion Hub.  Teams will be able to purchase the cables and adapters through the FIRST storefront.

Q: Can my existing sensors be used with the new REV Robotics Expansion Hub? 

A: For teams using existing Modern Robotics I²C sensors, because the Expansion Hub uses a 3.3V logic-level while the Modern Robotics sensors use a 5V logic-level. A team will need to use a special adapter cable with a logic-level converter included that will allow their 5V Modern Robotics I²C sensors to be used with the new Expansion Hub. Teams will be able to purchase the cables and adapters through the FIRST storefront. 

For the other Modern Robotics sensors (touch sensor and optical distance sensor) the REV Robotics Expansion Hub kit will include 3.3V alternative sensors that work directly with the Expansion Hub.

Teams also have the option of using their existing Modern Robotics Core Device Interface modules in parallel to an Expansion Hub to connect their existing 5V sensors to their Robot Controller.

Q: Can legacy NXT-style sensors be used directly with the new REV Robotics Expansion Hub? 

A: No, the new REV Robotics Expansion Hub does not have provisions to use the older style NXT sensors. 

Q: What sensors are included with the new REV Robotics Expansion Hub and will they be allowed for use in the FIRST�Tech Challenge?  

A: The new REV Robotics Expansion Hub will include a color-range sensor and a touch sensor.  Also, there is a built in inertial measurement unit (Bosch BNO055 9 axis absolute orientation sensor) built into each Expansion Hub.  Teams can use the color-range sensor as an optical distance sensor and as a color sensor.  Teams can use the touch sensor as a limit switch and touch sensor.  Teams can use the onboard IMU for inertial navigation. These sensors will be allowed for use in the FIRST� Tech Challenge.

Learn more about our new Rev Expansion hub here!