Scuttle code for following a red object

scuttle.py

import asyncio
​
from viam.robot.client import RobotClient
from viam.rpc.dial import Credentials, DialOptions
from viam.services.vision import VisionServiceClient
from viam.services.vision import VisModelConfig, VisModelType, Detection
from viam.components.camera import Camera
from viam.components.base import Base
​
​
async def connect():
   creds = Credentials(
        type='robot-location-secret',
        payload='[PLEASE ADD YOUR SECRET HERE. YOU CAN FIND THIS ON THE CODE SAMPLE TAB]')
   opts = RobotClient.Options(
        refresh_interval=0,
        dial_options=DialOptions(credentials=creds)
    )
   return await RobotClient.at_address('[ADD YOUR ROBOT ADDRESS HERE. YOU CAN FIND THIS ON THE CODE SAMPLE TAB]', opts)
​
# Get largest detection box and see if it's center is in the left, center, or right third
def leftOrRight(detections, midpoint):
   largest_area = 0
   largest = Detection()
   if not detections:
      print("nothing detected :(")
      return -1
   for d in detections:
      a = (d.x_max - d.x_min) * (d.y_max-d.y_min)
      if a > largest_area:
         a = largest_area
         largest = d
   centerX = largest.x_min + largest.x_max/2
   if centerX < midpoint-midpoint/6:
      return 0 #on the left
   if centerX > midpoint+midpoint/6:
      return 2 #on the right
   else:
      return 1  #basically centered
​
async def main():
   spinNum = 10        	# when turning, spin the motor this much
   straightNum = 300      	# when going straight, spin motor this much
   numCycles = 200        	# run the loop X times
   vel = 500             	# go this fast when moving motor
​
   # Connect to robot client and set up components
   robot = await connect()
   base = Base.from_robot(robot, 'base')
   camera = Camera.from_robot(robot, "cam")
   
   # Set up vision service with a color detector
   vision = VisionServiceClient.from_robot(robot)
   params = {'detect_color': '#a13b4c', 'hue_tolerance_pct': 0.06, 'segment_size': 1000}
   myBallDet = VisModelConfig(name="ball_detector", type=VisModelType("color_detector"), parameters=params)
   await vision.add_detector(myBallDet)
   
   
   frame = await camera.get_image()
   
   # Main loop. Detect the ball, determine if it's on the left or right, and head that way.
   # Repeat this for numCycles
   for i in range(numCycles):
      detections = await vision.get_detections_from_camera("cam", "ball_detector")
​
      answer = leftOrRight(detections, frame.size[0]/2)
      if answer == 0:
         print("left")
         await base.spin(spinNum, vel)    	# CCW is positive 
         await base.move_straight(straightNum, vel)
      if answer == 1:
         print("center")
         await base.move_straight(straightNum, vel)
      if answer == 2:
         print("right")
         await base.spin(-spinNum, vel)
      # If nothing is detected, nothing moves
      
      
   await robot.close()
​
# To test your connection, run this instead of main()
async def test():
	robot = await connect()
	print('Resources:')
	print(robot.resource_names)
​
​
if __name__ == '__main__':
  print("Starting up... ")
  asyncio.run(main())
  print("Done.")