11. Case 03: Turn at An Angle

11.1. Introduction

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Hello, we’ve learnt how to run a shape in case 02, but how can we draw a circle with the Ring:bit car? Let’s start this case with the question.

11.2. Hardware Connection

Also with the same assembly steps with former practices, connect the left wheel servo to P1 of the Ring:bit board and the right wheel servo to P2.

Use a rubber band to fix a pencil on the base board of the Ring:bit car.

11.3. Software Programming

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You should prepare the programming platform ready, if not, please can refer to this essay: Preparation for programming

Sample Projects

# Import the modules that we need
import board
from ringbit import *
from picoed import *

# Set the pins of the servos
ringbit = Ringbit(board.P2, board.P1)

# While true, detect if button A/B is pressed to make the [Ring:bit](https://shop.elecfreaks.com/products/elecfreaks-pico-ed-ring-bit-v2-car-kit-with-pico-ed-board?_pos=2&_sid=18032a345&_ss=r) car drive the circle or stop. 
while True:
    if button_a.is_pressed():
        ringbit.set_speed(-100, -50)
    elif button_b.is_pressed():
        ringbit.set_speed(0, 0)

Details of program:

1. Import the modules that we need. board is the common container, and you can connect the pins you’d like to use through it; ringbit module contains classes and functions for Ring:bit smart car operation; picoed module contains the operation functions to button A/B.

   import board
   from ringbit import *
   from picoed import *
   

2. Set the pins of the servos.

   ringbit = Ringbit(board.P2, board.P1)
   

3. While true, detect if button A/B is pressed to make the Ring:bit car drive the circle or stop.

   while True:
       if button_a.is_pressed():
           ringbit.set_speed(-100, -50)
       elif button_b.is_pressed():
           ringbit.set_speed(0, 0)
   

11.4. Result

On button A pressed, the car draws a circle.

On button B pressed, stop the car.

11.5. Exploration

How can you make your car draw a figure of eight?

11.6. FAQ

11.7. Relevant Files