RobotPy Simulation Support for CTRE Devices

[EthanWall]

I’ve been trying to simulate a Pigeon IMU with RobotPy recently, but I’m having some trouble. There is a BasePigeonSimCollection object in the ctre package that seems to do what I need, but it requires that I pass the PigeonIMU object to it, which I can’t figure out how to do from the physics.py file. The PigeonIMU does not appear in the Other Devices tab on the simulator.

So, is there any way to simulate the Pigeon in python? Thank you.

[virtuald]

Recent versions of pyfrc will optionally pass the robot object to your physics controller, from which you can get the necessary real motor/sensor objects.

Here’s the output of the latest ./robot.py create-physics:

#
# See the documentation for more details on how this works
#
# Documentation can be found at https://robotpy.readthedocs.io/projects/pyfrc/en/latest/physics.html
#
# The idea here is you provide a simulation object that overrides specific
# pieces of WPILib, and modifies motors/sensors accordingly depending on the
# state of the simulation. An example of this would be measuring a motor
# moving for a set period of time, and then changing a limit switch to turn
# on after that period of time. This can help you do more complex simulations
# of your robot code without too much extra effort.
#
# Examples can be found at https://github.com/robotpy/examples

import wpilib.simulation

from pyfrc.physics.core import PhysicsInterface
from pyfrc.physics import motor_cfgs, tankmodel
from pyfrc.physics.units import units

import typing

if typing.TYPE_CHECKING:
    from robot import MyRobot


class PhysicsEngine:
    """
    Simulates a 4-wheel robot using Tank Drive joystick control
    """

    def __init__(self, physics_controller: PhysicsInterface, robot: "MyRobot"):
        """
        :param physics_controller: `pyfrc.physics.core.Physics` object
                                   to communicate simulation effects to
        :param robot: your robot objet
        """

        self.physics_controller = physics_controller

        print("TODO: modify simulation for my robot")

        """
        # Change these parameters to fit your robot!

        # Motors
        self.l_motor = wpilib.simulation.PWMSim(1)
        self.r_motor = wpilib.simulation.PWMSim(2)

        bumper_width = 3.25 * units.inch

        self.drivetrain = tankmodel.TankModel.theory(
            motor_cfgs.MOTOR_CFG_CIM,           # motor configuration
            110 * units.lbs,                    # robot mass
            10.71,                              # drivetrain gear ratio \omega In/\omega Out
            2,                                  # motors per side
            22 * units.inch,                    # robot wheelbase
            23 * units.inch + bumper_width * 2, # robot width
            32 * units.inch + bumper_width * 2, # robot length
            6 * units.inch,                     # wheel diameter
        )
        """

    def update_sim(self, now, tm_diff):
        """
        Called when the simulation parameters for the program need to be
        updated.

        :param now: The current time as a float
        :param tm_diff: The amount of time that has passed since the last
                        time that this function was called
        """

        """
        # Simulate the drivetrain
        l_motor = self.l_motor.getSpeed()
        r_motor = self.r_motor.getSpeed()

        transform = self.drivetrain.calculate(l_motor, r_motor, tm_diff)
        pose = self.physics_controller.move_robot(transform)
        """

[EthanWall]

Thank you very much!