describe the different components and subsystems of the robot here (from a practical perspective), including the two types of batteries and the ESP LEDs.

Robot Components and Subsystems

Overview

• Broadly speaking, all robots we use have at least these key electrical components:

  1. ESP32 Microcontroller

  2. “ESP Battery”

  3. Main Power Battery

  4. Sabertooth Motor Controller

  5. Drive Motors

  6. Main Power Switch

• Some robots have additional sensors or actuators which are programmed via specialized subclasses of the base Robot class.

  • Notable examples include the Quarterback V3 or the Center V2.

  • Robots capable of legally carrying the football must typically be equipped with a tackle sensor.

Component Diagram

Below is an image of a standard lineman with the aforementioned electrical components marked.

Component Descriptions

ESP32 Microcontroller

See also

More information on this component can be found at the main article: ESP32

The ESP32 microcontroller is the “brain” of the robot and serves as the main processing hub for driver control inputs from the PS5 controller.

“ESP Battery”

• An 18650 Lithium Cell 7.7V battery pack powers the ESP32 microcontroller exclusively.

  • This battery is electrically separated from the rest of the robot save for any interface wires between the ESP and other electrical devices.

• Note that unlike the main power battery, this does not have a switch - once plugged in, the ESP32 will turn on immediately.

• Some older robots do not have this battery, and instead have the ESP32 microcontroller connected to the main power battery

Main Power Battery

• The remainder of the robot (including the drive motors and Sabertooth) are powered by the main power battery (or just “battery”).

  • For most robots, this is a Kobalt 24V Drill Battery.

  • For certain robots (the running backs or the Quarterback V3), it is be a 12V sealed lead-acid (SLA) battery.

Sabertooth Motor Controller

See also

More information on this component can be found in its main articles: ST 2x25 and ST 2x32.

• The Sabertooth motor controller is what converts the PWM signal from the ESP32 microcontroller into a DC voltage sent to the motors.

  • This is a 24V device and runs off of the main power battery.

    • Robots that use a 12V SLA battery as their main power battery typically have a different type of motor controller, usually integrated into (Falcons) or attached to (NEOs) the motor.

  • There are two different types of Sabertooth motor controllers: the 2x25 and the 2x32.

Drive Motors

• The drive motors are mechanically attached to the wheels of the robot, typically via a geartrain, and serve as the robot’s primary method of locomotion.

• Usually these are AmpFlow motors, of which we have three types, all 24V:

  • “Big” - AmpFlow E30-400-24

  • “Small” - AmpFlow E30-150-24

  • “Pancake” - AmpFlow P40-350-24

• Other motor types include:

  • Falcon 500 (12V, used in the running back C and the turret of the Quarterback V3)

  • NEO Vortex (12V, used in the running back 1.21)

  • Torquenado (12V, used in the mecanum center and V1 linemen)

Main Power Switch

• This mechanical switch controls whether the main power battery is actively supplying power to the drive motors, motor controller, and other subsystems (if applicable).

• Various different types of power switches are used (from flip-switches to rotating switches). However, they are all typically clearly visible and accessible near the edge of the robot.

• Notably, the Quarterback V3 has two power switches, one for the top and one for the bottom (since they are technically two separate robots).

Tackle Sensor

• Ball-carrying robots are usually required to carry a tackle sensor, which is a fancy accelerometer that triggers the lights to change to red when the robot is impacted (or, in some cases, increases rapidly in speed).

• We have revision 3 and revision 4 tackle sensors.