🤖 Drive a Robot Car with Python · ขับหุ่นยนต์ด้วย Python · 用 Python 开机器人小车

Download find.py

"""Step 2 - Find the robot car.

This script only looks. It does not move the car.

Run it:
    Windows:  python find.py
    Mac:      python3 find.py

Install bleak first:
    Windows:  python -m pip install bleak
    Mac:      python3 -m pip install bleak

On a Mac, say yes when it asks for Bluetooth.
If you miss it: System Settings > Privacy and Security >
Bluetooth > turn on your Terminal app.
"""
import asyncio

from bleak import BleakScanner


async def main():
    print("Looking for the robot...")
    devices = await BleakScanner.discover(timeout=10)

    found = False
    for d in devices:
        if d.name and "micro:bit" in d.name:
            print("Found it:", d.name)
            found = True

    if not found:
        print("No robot.")
        print("Is the car on?")
        print("Is the phone app closed?")
        print("Are you near the car?")


asyncio.run(main())

Download light.py

"""Step 3 - Turn the lights on and off.

This script is safe. The car does not move.
Start here. If this works, your Bluetooth works.

Run it:
    Windows:  python light.py
    Mac:      python3 light.py

Install bleak first:
    Windows:  python -m pip install bleak
    Mac:      python3 -m pip install bleak

On a Mac, say yes when it asks for Bluetooth.
If you miss it: System Settings > Privacy and Security >
Bluetooth > turn on your Terminal app.
"""
import asyncio

from bleak import BleakClient, BleakScanner

# The robot's letter box. Messages go here.
BOX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"


async def say(car, command):
    """Send one command to the robot."""
    await car.write_gatt_char(BOX, command.encode() + b"#", response=False)
    await asyncio.sleep(0.05)


async def find_robot():
    """Look for the car and give it back."""
    return await BleakScanner.find_device_by_filter(
        lambda d, a: d.name and "micro:bit" in d.name)


async def main():
    print("Looking for the robot...")
    robot = await find_robot()
    if robot is None:
        print("No robot. Is it on? Is the phone app closed?")
        return
    print("Found it:", robot.name)

    async with BleakClient(robot) as car:
        for name, code in [("red", "G"), ("green", "H"), ("blue", "I")]:
            print("Light is", name)
            await say(car, code)
            await asyncio.sleep(1)
        await say(car, "M")
        print("Lights off.")

    print("Done.")


asyncio.run(main())

Download song.py

"""Step 6 - Play a song with flashing lights.

This script is safe. The car does not move.

The numbers are notes.
1=do 2=re 3=mi 4=fa 5=sol 6=la 7=si 8=high do.
A space is a rest.

Run it:
    Windows:  python song.py
    Mac:      python3 song.py

Install bleak first:
    Windows:  python -m pip install bleak
    Mac:      python3 -m pip install bleak

On a Mac, say yes when it asks for Bluetooth.
If you miss it: System Settings > Privacy and Security >
Bluetooth > turn on your Terminal app.
"""
import asyncio

from bleak import BleakClient, BleakScanner

BOX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"

# Twinkle Twinkle Little Star. Change this and make your own song.
SONG = "1155665443322 1"

# Each note gets a colour. So the lights follow the music.
COLOUR = {"1": "G", "2": "J", "3": "H", "4": "K",
          "5": "I", "6": "L", "7": "G", "8": "J"}

BEAT = 0.4          # how long one note lasts
ON = 0.7            # how much of the beat the light stays on


async def say(car, command):
    """Send one command to the robot."""
    await car.write_gatt_char(BOX, command.encode() + b"#", response=False)
    await asyncio.sleep(0.05)


async def find_robot():
    return await BleakScanner.find_device_by_filter(
        lambda d, a: d.name and "micro:bit" in d.name)


async def play(car, song):
    for note in song:
        if note == " ":
            await asyncio.sleep(BEAT)
            continue
        await say(car, note)              # the sound
        await say(car, COLOUR[note])      # the light
        await asyncio.sleep(BEAT * ON)
        await say(car, "M")               # light off
        await asyncio.sleep(BEAT * (1 - ON))


async def main():
    print("Looking for the robot...")
    robot = await find_robot()
    if robot is None:
        print("No robot. Is it on? Is the phone app closed?")
        return
    print("Found it:", robot.name)

    async with BleakClient(robot) as car:
        print("Playing a song.")
        try:
            await play(car, SONG)
        finally:
            await say(car, "M")
            print("Lights off.")

    print("Done.")


asyncio.run(main())

Download move.py

"""Step 5 - Drive the car with the keyboard.

WARNING: the car MOVES. Put it on the floor first.
It can fall off a table.

Type keys, then press Enter:
    w = forward     s = back
    a = turn left   d = turn right
    q = spin left   e = spin right
    x = quit

You can type more than one key. "wwd" goes forward twice, then turns.
Every key moves the car for a short time. Then the car stops by itself.
So the car can never run away from you.

Run it:
    Windows:  python move.py
    Mac:      python3 move.py

Install bleak first:
    Windows:  python -m pip install bleak
    Mac:      python3 -m pip install bleak

On a Mac, say yes when it asks for Bluetooth.
If you miss it: System Settings > Privacy and Security >
Bluetooth > turn on your Terminal app.
"""
import asyncio

from bleak import BleakClient, BleakScanner

BOX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"

# One key, one command.
KEYS = {
    "w": "A",   # forward
    "s": "B",   # back
    "a": "C",   # turn left
    "d": "D",   # turn right
    "q": "E",   # spin left
    "e": "F",   # spin right
}

# How long one key moves the car.
# Make it bigger for longer steps.
STEP = 0.5


async def say(car, command):
    """Send one command to the robot."""
    await car.write_gatt_char(BOX, command.encode() + b"#", response=False)
    await asyncio.sleep(0.05)


async def find_robot():
    return await BleakScanner.find_device_by_filter(
        lambda d, a: d.name and "micro:bit" in d.name)


async def drive(car):
    print()
    print("w = forward     s = back")
    print("a = turn left   d = turn right")
    print("q = spin left   e = spin right")
    print("x = quit")
    print()

    while True:
        # Wait for typing. to_thread keeps Bluetooth alive while we wait.
        line = await asyncio.to_thread(input, "> ")
        line = line.strip().lower()

        if line == "x":
            return

        for key in line:
            if key not in KEYS:
                print("  I do not know", key)
                continue
            await say(car, KEYS[key])       # go
            await asyncio.sleep(STEP)
            await say(car, "0")             # stop again


async def main():
    print("Looking for the robot...")
    robot = await find_robot()
    if robot is None:
        print("No robot. Is it on? Is the phone app closed?")
        return
    print("Found it:", robot.name)

    async with BleakClient(robot) as car:
        print("Put the car on the floor.")
        try:
            await drive(car)
        finally:
            # This always runs. So the car always stops.
            for i in range(3):
                await say(car, "0")
                await asyncio.sleep(0.15)
            print("Stopped.")

    print("Done.")


asyncio.run(main())

Download robot.py

"""Step 7 - The whole program.

It finds the car. It plays a song with lights.
Then it drives a circle. Then it stops.

WARNING: the car MOVES. Put it on the floor first.

Run it:
    Windows:  python robot.py
    Mac:      python3 robot.py

Install bleak first:
    Windows:  python -m pip install bleak
    Mac:      python3 -m pip install bleak

On a Mac, say yes when it asks for Bluetooth.
If you miss it: System Settings > Privacy and Security >
Bluetooth > turn on your Terminal app.
"""
import asyncio

from bleak import BleakClient, BleakScanner

BOX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"

SONG = "1155665443322 1"
COLOUR = {"1": "G", "2": "J", "3": "H", "4": "K",
          "5": "I", "6": "L", "7": "G", "8": "J"}


async def say(car, command):
    """Send one command to the robot."""
    await car.write_gatt_char(BOX, command.encode() + b"#", response=False)
    await asyncio.sleep(0.05)


async def find_robot():
    return await BleakScanner.find_device_by_filter(
        lambda d, a: d.name and "micro:bit" in d.name)


async def main():
    print("Looking for the robot...")
    robot = await find_robot()
    if robot is None:
        print("No robot. Is it on? Is the phone app closed?")
        return
    print("Found it:", robot.name)

    async with BleakClient(robot) as car:
        try:
            print("Playing a song.")
            for note in SONG:
                if note == " ":
                    await asyncio.sleep(0.4)
                    continue
                await say(car, note)
                await say(car, COLOUR[note])
                await asyncio.sleep(0.3)
                await say(car, "M")
                await asyncio.sleep(0.1)

            print("Driving in a circle.")
            for i in range(8):
                await say(car, "A")          # forward
                await asyncio.sleep(0.25)
                await say(car, "C")          # turn left
                await asyncio.sleep(0.40)
        finally:
            # This always runs, even if something breaks.
            # So the car always stops.
            for i in range(3):
                await say(car, "0")
                await asyncio.sleep(0.15)
            await say(car, "M")
            print("Stopped.")

    print("Done.")


asyncio.run(main())

Download faces.py

"""Faces and letters for a 5x5 grid of lights.

The micro:bit screen is 25 lights in a 5 by 5 grid. A picture for it is
five numbers, one for each row. Numbers are hard to read, so here you
draw each picture with dots and hashes instead.

This draws in your terminal. It needs no robot and no Bluetooth, so it
works on any computer.

    python faces.py                  # a smile
    python faces.py heart            # one picture
    python faces.py HELLO            # spell a word
    python faces.py font             # show everything

Run it:
    Windows:  python faces.py heart
    Mac:      python3 faces.py heart
"""
import sys


def icon(*rows):
    """Five strings of dots and hashes -> five numbers.

    One number for each row. Bit 4 is the LEFT light, bit 0 the right one.
    """
    out = bytearray()
    for row in rows:
        value = 0
        for i, ch in enumerate(row[:5]):
            if ch not in ". 0_":
                value |= 1 << (4 - i)
        out.append(value)
    return bytes(out)


FACES = {
    "smile": icon(".#.#.", ".#.#.", ".....", "#...#", ".###."),
    "sad":   icon(".#.#.", ".#.#.", ".....", ".###.", "#...#"),
    "wink":  icon(".#...", ".#.##", ".....", "#...#", ".###."),
    "flat":  icon(".#.#.", ".#.#.", ".....", "#####", "....."),
    "heart": icon(".#.#.", "#####", "#####", ".###.", "..#.."),
    "yes":   icon(".....", "....#", "...#.", "#.#..", ".#..."),
    "no":    icon("#...#", ".#.#.", "..#..", ".#.#.", "#...#"),
    "up":    icon("..#..", ".###.", "#.#.#", "..#..", "..#.."),
    "down":  icon("..#..", "..#..", "#.#.#", ".###.", "..#.."),
}

FONT = {
    " ": icon(".....", ".....", ".....", ".....", "....."),
    "A": icon(".###.", "#...#", "#####", "#...#", "#...#"),
    "B": icon("####.", "#...#", "####.", "#...#", "####."),
    "C": icon(".####", "#....", "#....", "#....", ".####"),
    "D": icon("####.", "#...#", "#...#", "#...#", "####."),
    "E": icon("#####", "#....", "####.", "#....", "#####"),
    "F": icon("#####", "#....", "####.", "#....", "#...."),
    "G": icon(".####", "#....", "#..##", "#...#", ".###."),
    "H": icon("#...#", "#...#", "#####", "#...#", "#...#"),
    "I": icon("#####", "..#..", "..#..", "..#..", "#####"),
    "J": icon("#####", "..#..", "..#..", "#.#..", ".##.."),
    "K": icon("#...#", "#..#.", "###..", "#..#.", "#...#"),
    "L": icon("#....", "#....", "#....", "#....", "#####"),
    "M": icon("#...#", "##.##", "#.#.#", "#...#", "#...#"),
    "N": icon("#...#", "##..#", "#.#.#", "#..##", "#...#"),
    "O": icon(".###.", "#...#", "#...#", "#...#", ".###."),
    "P": icon("####.", "#...#", "####.", "#....", "#...."),
    "Q": icon(".###.", "#...#", "#...#", "#..#.", ".##.#"),
    "R": icon("####.", "#...#", "####.", "#..#.", "#...#"),
    "S": icon(".####", "#....", ".###.", "....#", "####."),
    "T": icon("#####", "..#..", "..#..", "..#..", "..#.."),
    "U": icon("#...#", "#...#", "#...#", "#...#", ".###."),
    "V": icon("#...#", "#...#", "#...#", ".#.#.", "..#.."),
    "W": icon("#...#", "#...#", "#.#.#", "##.##", "#...#"),
    "X": icon("#...#", ".#.#.", "..#..", ".#.#.", "#...#"),
    "Y": icon("#...#", ".#.#.", "..#..", "..#..", "..#.."),
    "Z": icon("#####", "...#.", "..#..", ".#...", "#####"),
    "0": icon(".###.", "#..##", "#.#.#", "##..#", ".###."),
    "1": icon("..#..", ".##..", "..#..", "..#..", ".###."),
    "2": icon("###..", "...#.", "..#..", ".#...", "#####"),
    "3": icon("####.", "....#", "..##.", "....#", "####."),
    "4": icon("#...#", "#...#", "#####", "....#", "....#"),
    "5": icon("#####", "#....", "####.", "....#", "####."),
    "6": icon(".###.", "#....", "####.", "#...#", ".###."),
    "7": icon("#####", "....#", "...#.", "..#..", ".#..."),
    "8": icon(".###.", "#...#", ".###.", "#...#", ".###."),
    "9": icon(".###.", "#...#", ".####", "....#", ".###."),
    "!": icon("..#..", "..#..", "..#..", ".....", "..#.."),
    "?": icon(".###.", "#...#", "...#.", ".....", "..#.."),
}


def render(bitmap, label=""):
    """Print a picture in the terminal."""
    if label:
        print(f"  {label}")
    for row in bitmap:
        line = "".join("#" if (row >> (4 - i)) & 1 else "." for i in range(5))
        print("   ", line.replace("#", "[]").replace(".", " ."))
    print("    numbers:", " ".join(str(b) for b in bitmap))
    print()


def show(what):
    """Draw a face, a letter, or a whole word."""
    if what.lower() == "font":
        for name, bm in list(FACES.items()) + list(FONT.items()):
            render(bm, name)
        return

    if what.lower() in FACES:
        render(FACES[what.lower()], what.lower())
        return

    for ch in what.upper():
        bm = FONT.get(ch)
        if bm is None:
            print(f"  I have no picture for {ch!r}\n")
        else:
            render(bm, ch)


if __name__ == "__main__":
    show(" ".join(sys.argv[1:]) or "smile")

Download track.py

"""Step 9 - the car follows a black line by itself.

WARNING: the car DRIVES ITSELF. Put it on the floor first.

PUT THE CAR ON THE BLACK LINE BEFORE YOU START.
If it does not start on the line, it just drives in circles
looking for one.

    python track.py

Run it:
    Windows:  python track.py
    Mac:      python3 track.py

Install bleak first:
    Windows:  python -m pip install bleak
    Mac:      python3 -m pip install bleak

This script only uses line mode (S#). Yahboom's sheet lists two more
modes, T# and U#. Do NOT use them. They drive the car and 0# does not
stop them - only the power switch does. Tested on a real car.
"""
import asyncio
import sys

from bleak import BleakClient, BleakScanner

BOX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"

SECONDS = 15


async def say(car, command):
    """Send one command to the robot."""
    await car.write_gatt_char(BOX, command.encode() + b"#", response=False)
    await asyncio.sleep(0.05)


async def find_robot():
    return await BleakScanner.find_device_by_filter(
        lambda d, a: d.name and "micro:bit" in d.name)


async def main(seconds):
    print("Looking for the robot...")
    robot = await find_robot()
    if robot is None:
        print("No robot. Is it on? Is the phone app closed?")
        return
    print("Found it:", robot.name)

    async with BleakClient(robot) as car:
        print()
        print("Put the car ON the black line now.")
        print("It will follow the line by itself.")
        for n in [5, 4, 3, 2, 1]:
            print("  starting in", n)
            await asyncio.sleep(1)

        try:
            await say(car, "S")            # line mode on
            print("  following the line for", seconds, "seconds...")
            await asyncio.sleep(seconds)
        finally:
            # Send the stop more than once. One lost message would
            # leave the car driving.
            for i in range(3):
                await say(car, "0")
                await asyncio.sleep(0.15)
            print("Stopped.")

    print("Done.")


asyncio.run(main(float(sys.argv[1]) if len(sys.argv) > 1 else SECONDS))

Download smile.py

"""Make the robot smile.

Yahboom's firmware draws a happy face while Bluetooth is connected,
and a sad face when it disconnects. So to make the bot smile, we
connect and simply hold the connection open.

    python smile.py        # smile for 30 seconds
    python smile.py 120    # smile for 2 minutes

Run it:
    Windows:  python smile.py
    Mac:      python3 smile.py

Install bleak first:
    Windows:  python -m pip install bleak
    Mac:      python3 -m pip install bleak
"""
import asyncio
import sys

from bleak import BleakClient, BleakScanner


async def main(seconds):
    print("Looking for the robot...")
    robot = await BleakScanner.find_device_by_filter(
        lambda d, a: d.name and "micro:bit" in d.name)
    if robot is None:
        print("No robot. Is it on? Is the phone app closed?")
        return
    print("Found it:", robot.name)

    async with BleakClient(robot) as car:
        print(f"Connected - the robot is smiling for {seconds}s.")
        try:
            await asyncio.sleep(seconds)
        except KeyboardInterrupt:
            pass
    print("Disconnected - it goes sad again.")


asyncio.run(main(float(sys.argv[1]) if len(sys.argv) > 1 else 30))