Microbit handle control

1. Learning objectives

In this course, we mainly learn how to use Python programming to control the flying car with the microbit handle.

2. Building blocks

For the building blocks steps, please refer to the installation drawings of [Assembly course]-[Pretty car] in the materials or the building blocks installation book.

3. Motor wiring

Insert the motor wiring on the left side of the car into the M1 interface of the Super:bit expansion board, and the black line is close to the battery side;

Insert the motor wiring on the right side of the car into the M3 interface of the Super:bit expansion board, and the black line is close to the battery side;

As shown below:

4. Code analysis

4.1 Flying car

For the program, please refer to the Pretty car code.py file.

from microbit import *
import superbit
import radio
import neopixel

First, import the libraries needed for this lesson from microbit: the superbit library is dedicated to the superbit expansion board; neopixel is used to control RGB lights; radio is used for the wireless communication function of micro:bit.

​x
Red = (255, 0, 0)
Orange = (255, 165, 0)
Yellow = (255, 255, 0)
Green = (0, 255, 0)
Blue = (0, 0, 255)
Violet = (148, 0, 211)
White = (255, 255, 255)
color_lib = { 
'Red': Red, 'Orange': Orange, 'Yellow': Yellow, 'Green': Green, 
'Blue': Blue, 'Violet': Violet, 'White': White}
def RGBLight_more_show(first, num, color): 
global np 
​
np.clear() 
for i in range(first, first + num): 
np[i] = color_lib[color] np.show()

This section of the program is used to define RGB lights of different colors, and define the function RGBLight_more_show to control the color of the RGB light. This function will be called in the subsequent main loop.

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np = neopixel.NeoPixel(pin12, 4)
display.show(Image.HEART)
radio.on()
radio.config(group=1)

display.show(Image.HAPPY): Display a smiley face pattern on the microbit dot matrix;

np = neopixel.NeoPixel(pin12, 4): Initialize the RGB light settings. There are 4 RGB lights in total, connected to the P12 pin of the microbit motherboard (you can check the hardware interface manual);

radio.on(): Turn on the wireless function. Because the wireless function consumes more power and occupies more memory, it is turned off by default. You can also use radio.off() to turn off the wireless function;

radio.config(group=1): Configure wireless group=1, so that other microbit devices with wireless group=1 can communicate with each other. The default is 0. The selectable group is 0~255. The set group value needs to be consistent with the handle setting, otherwise it cannot communicate normally;

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while True:
incoming = radio.receive()
if incoming == 'up':
superbit.motor_control(superbit.M1, 255, 0)
superbit.motor_control(superbit.M3, 255, 0)
...

In the main loop, determine whether the car receives the command sent by the handle, and control the movement state of the car and the color of the RGB light.

incoming = radio.receive(): Receive the data transmitted wirelessly and save it to the incoming variable; if incoming is 'up', the car moves forward, 'down' makes the car move backward, 'left' makes the car turn left, 'right' makes the car turn right, and 'stop' makes the car stop;

If incoming is 'R', the body RGB lights up red, 'G' makes the body RGB light up green, 'B' makes the body RGB light up blue, and 'Y' makes the body RGB light up yellow.

! Note:

The incoming value must correspond to the value sent by the handle. Only the same value can receive and execute commands.

4.2 Handle

Please refer to the Handle code.py file for the program.

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from microbit import display, Image
import ghandle
import radio

First, import the libraries needed for this lesson from microbit: the ghandle library is dedicated to the micro:bit hand; radio is used for the wireless communication function of micro:bit.

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display.show(Image.HEART)
radio.on()
radio.config(group=1)

display.show(Image.HEART): Display a heart pattern on the microbit dot matrix;

radio.on(): Turn on the wireless function. Because the wireless function consumes more power and occupies more memory, it is turned off by default. You can also use radio.off() to turn off the wireless function;

radio.config(group=1): Configure wireless group=1, so that other microbit devices with wireless group=1 can communicate with each other. The default is 0, and the selectable group is 0~255. The set group value needs to be consistent with the handle setting, otherwise it will not communicate normally;

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 Dancer
Dancing and singing