# Case 03: Turn at An Angle ![](./images/case03.png) ## Introduction --- Hello, we've learnt how to run a shape in case 02, but how can we draw a circle with 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? Let's start this case with the question. ## Hardware Connection Also with the same assembly steps with former practices, connect the left wheel servo to P1 of 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) board and the right wheel servo to P2. ![](./images/case.png) Use a rubber band to fix a pencil on the base board of 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. ![](./images/case0301.png) ## Software Programming --- You should prepare the programming platform ready, if not, please can refer to this essay: [Preparation for programming](https://www.elecfreaks.com/learn-en/pico-ed/index.html) ### Sample Projects ```python # 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](https://shop.elecfreaks.com/products/elecfreaks-pico-ed-ring-bit-v2-car-kit-with-pico-ed-board?_pos=2&_sid=18032a345&_ss=r) smart car operation; `picoed` module contains the operation functions to button A/B. ```python import board from ringbit import * from picoed import * ``` 2. Set the pins of the servos. ```python ringbit = Ringbit(board.P2, board.P1) ``` 3. 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. ```python while True: if button_a.is_pressed(): ringbit.set_speed(-100, -50) elif button_b.is_pressed(): ringbit.set_speed(0, 0) ``` ## Result On button A pressed, the car draws a circle. On button B pressed, stop the car. ## Exploration How can you make your car draw a figure of eight? ## FAQ ## Relevant Files