The FTC Control System
The FIRST Tech Challenge seeks to inspire youth to become the next generation of STEM leaders and innovators through participation in mentor-guided robotics competition. Teams who participate in the FIRST Tech Challenge must build a robot that performs a variety of tasks. The tasks vary from season to season, and are based on a set of game rules that are published at the start of each season. The more tasks that a robot can complete, the more points a team will earn.
A FIRST Tech Challenge match has an autonomous phase and a driver-controlled or "tele-operated" phase. In the autonomous phase of a match the robot operates without any human input or control. In the driver-controlled phase, the robot can receive input from up to two human drivers.
The FIRST Tech Challenge uses Android phones to control its robots. During a competition, each team has two Android phones.
One phone is mounted onto the robot and is called the Robot Controller. The Robot Controller acts as the “brains” of the robot. It does all of the thinking for the robot and tells the robot what to do. It consists of an Android device running the FTC Robot Controller app.
A second phone sits with the team drivers and has one or two gamepads connected. This second phone is known as the Driver Station. The Driver Station is sort of like a remote control that you might use to control your television. The Driver Station allows a team to communicate remotely (using a secure, wireless connection) to the Robot Controller and to issue commands to the Robot Controller. The Driver Station consists of an Android device running the FTC Driver Station app.
The REV Robotics Expansion Hub is the electronic input/output (or “I/O”) module that lets the Robot Controller talk to the robot’s motors, servos, and sensors. The Robot Controller communicates with the Expansion Hub through a USB connection. The Expansion Hub is connected to a 12V battery which is used to power the Expansion Hub, the motors, the servos and sensors. The Robot Controller typically has its own internal battery, which can also be charged through the USB cable connected to the Expansion Hub.
During a typical FIRST Tech Challenge match, a team’s robot has to perform a variety of tasks in an effort to score points. For example, a team might want their robot to follow a white line on the competition floor and then score a game element into a goal autonomously during a match. Teams write “op modes” (which stand for “operational modes”) to specify the behavior for their robot.
Op Modes are computer programs that are used to customize the behavior of a competition robot. The Robot Controller can execute a selected op mode to perform certain tasks during a match.
Teams who are participating in the FIRST Tech Challenge have a variety of programming tools that they can use to create their own op modes. Teams can use a visual ("drag and drop") programming tool called the FTC Blocks Programming Tool to create their op modes. Teams can also use a text-based Java tool to create their op modes.