A team in a game

Radio in a game, agreeing roles without talking, and swapping jobs when the score says so.

10.5CompetingRobot club14 min

Do this lesson in the simulator

Print it: worksheet (PDF) · answers (PDF) · as a web page

Shuttle Relay, Control Points, Dodgeball and Capture the Flag are won by teams, and a team that has not agreed anything is two robots doing the same job.

Saying who does what

The radio from Module 9 works in a game exactly as it did in the lesson: send(text) goes to every robot on the mat, and messages() gives you what has arrived since you last looked.

from bugbot import *
connect()

# in a game, the first thing a team does is agree who is doing what
send("striker")
for m in messages():
    print("heard:", m)

Run this in the simulator

Everyone hears everything, including the other team. Say what your team needs and nothing you would mind an opponent knowing.

A rule that settles it without talking

Radio is useful, but two robots can agree without a word if they follow the same rule. The usual one is by name or by number: the robot whose name sorts first attacks, the other defends.

from bugbot import *
connect()

me = "bugbot-2"
team = ["bugbot-2", "bugbot-7"]
job = "attack" if me == min(team) else "defend"
print(me, "is going to", job)

Run this in the simulator

That is worth knowing because a rule cannot be jammed, cannot arrive late, and works on the first tick of the game.

Swapping jobs

Fixed jobs lose to a team that notices. The pattern is: do your job, watch the score, and swap when it makes sense.

  • Attacker taken out? The defender becomes the attacker.
  • Two goals ahead with ten seconds left? Everyone defends.
  • Both chasing the same ball? The nearer one takes it, and says so.
# the shape of it, inside the game loop. In Control Points, Capture the Flag and Dodgeball,
# info()['score'] holds every team's score, such as {'red': 2, 'blue': 3}
score = info()['score']
mine = score[info()['team']]
best_other = max(v for t, v in score.items() if t != info()['team'])
if mine < best_other and clock() > 40:
    job = "attack"

Task: call it and go

Send a message saying which job you are taking, then do it: drive to the base zone that matches. This time the job is attack: send attack, then drive to the far base, up the mat and to the left. (Defending would mean the near base, down and to the right.)

from bugbot import *
connect()

# say what you are doing, then do it
send("attack")

Challenges

  1. Choose the job from the robot's own name with min(), as above, and send what you chose.
  2. Print everything messages() gives you for ten seconds, so you can see what a busy game sounds like.
  3. Send a message when you arrive, so a team mate knows the job is done.