Examples

Python Examples

This page provides example usage in Python with our APIs

Compiling Proto Files to Python

Use the protoc compiler to generate Python files from your .proto files.

For example, to drive the robot we need the Service from robot_api_service.proto and Twist message from math.proto

python -m grpc_tools.protoc -I=/path_to_repository/bearrobotics-public/base/ --python_out=. --grpc_python_out=. bearrobotics/api/v0/robot/robot_api_service.proto

python -m grpc_tools.protoc -I=/path_to_repository/bearrobotics-public/base/ --python_out=. bearrobotics/api/v0/common/math.proto 

Driving the Robot

Prerequisite: Compiled pb2 files for robot_api_service and math

Script: The following script turns the robot in place at 0.2 m/s at a set rate of 15Hz. To stop the robot from rotating, terminate the script.

import time
import grpc
from math_pb2 import Twist
from robot_api_service_pb2 import DriveRobotRequest
from robot_api_service_pb2_grpc import RobotServiceStub

# Server details
SERVER_ADDRESS = "10.10.127.2:5123"

# Twist parameters
LINEAR_VELOCITY = 0.0  # m/s
ANGULAR_VELOCITY = 0.2  # rad/s
PUBLISH_RATE = 15  # Hz

def main():
    # Establish a gRPC channel
    channel = grpc.insecure_channel(SERVER_ADDRESS)
    stub = RobotServiceStub(channel)

    try:
        while True:
            # Create a Twist message
            twist = Twist(
                linear_velocity=LINEAR_VELOCITY,
                angular_velocity=ANGULAR_VELOCITY
            )

            # Create a DriveRobotRequest
            request = DriveRobotRequest(twist=twist)

            # Send the request 
            stub.DriveRobot(iter([request]))
            print(f"Published: linear_velocity={LINEAR_VELOCITY}, angular_velocity={ANGULAR_VELOCITY}")

            # Maintain 15 Hz publishing rate
            time.sleep(1 / PUBLISH_RATE)
    except KeyboardInterrupt:
        print("Stopped publishing.")

if __name__ == "__main__":
    main()