Package: ev3-dc
Use python3 to program your LEGO Mindstorms EV3. The program runs on
the local host and sends direct commands to the EV3 device. It
communicates via Bluetooth, WiFi or USB. There is no need to boot the
EV3 device from an SD Card or manipulate its software. You can use it
as it is, the EV3 is designed to execute commands which come from
outside. If you prefer coding from scratch, read thisblog, if you like to benefit from
preliminary work, then use moduleev3_dc.Installationpython3 -m pip install --user ev3_dcExamplesWriting and sending direct commandsThe following program communicates via USB with an EV3 device and
plays a tone with a frequency of 440 Hz for a duration of 1 sec. This
says, you need to connect the EV3 device and your computer with an USB
cable.import ev3_dc as ev3

my_ev3 = ev3.EV3(protocol=ev3.USB)
my_ev3.verbosity = 1
ops = b''.join((
    ev3.opSound,
    ev3.TONE,
    ev3.LCX(1),  # VOLUME
    ev3.LCX(440),  # FREQUENCY
    ev3.LCX(1000),  # DURATION
))
my_ev3.send_direct_cmd(ops)The output shows the request, which was sent to the EV3 device and the
corresponding response:13:02:23.425843 Sent 0x|0E:00|2A:00|00|00:00|94:01:01:82:B8:01:82:E8:03|
13:02:23.432733 Recv 0x|03:00|2A:00|02|Subclasses of EV3 with specialized APIsMethodplay_toneof classJukeboxalso plays tones:import ev3_dc as ev3

jukebox = ev3.Jukebox(protocol=ev3.BLUETOOTH, host='00:16:53:42:2B:99')
jukebox.verbosity = 1
jukebox.play_tone("a'", duration=1)This program does the very same thing via Bluetooth! Before you can
run it, you need to pair the two devices (the computer, that
executes the program and the EV3 device) and replace the MAC-address00:16:53:42:2B:99by the one of your EV3. The output:13:05:11.324701 Sent 0x|0E:00|2A:00|80|00:00|94:01:01:82:B8:01:82:E8:03|Some remarks:ProtocolUSBreplies all requests to provide
collisions. ProtocolBLUETOOTHis much slower and replies only
requests, which demand it.Moduleev3_dcprovides objects with specialized
functionality. Behind the scene, this functionality depends on
messages, which are sent to the EV3 device and replied by the EV3
device.Independent TasksSpecialized classes (e.g. classJukebox)
provide factory methods, which returnthread_task.Taskobjects. Thread
tasks allow to start, stop and continue independent tasks.import ev3_dc as ev3

jukebox = ev3.Jukebox(protocol=ev3.WIFI)
antemn = jukebox.song(ev3.EU_ANTEMN)

antemn.start()This program plays the EU antemn. Before you can execute it, you need
to connect both devices (the computer, that runs the program and the
EV3 device) with the same LAN (local area network), the EV3 device
must be connected via WiFi. If you don’t own a WiFi dongle, modify the
protocol and select ev3.BLUETOOTH or ev3.USB.Some remarks:Methodsong()returns a thread_task.Task object and we need to
start it explicitly. It plays tones and changes the LED-colors.Starting a thread task does not block the program nor does it
block the EV3 device. It runs in the background and allows to do
additional things parallel.Alternatively, you can start a thread task without mutlithreading
byantemn.start(thread=False). This lets it behave like any
normal callable.Specialized Subclasses handle Sensors and MotorsSpecialized subclasses of classEV3,
likeTouch,Infrared,Ultrasonic,Color,Gyro,Motor,TwoWheelVehicle,SoundorVoicehandle sensors, motors, sound or text to speech. You can use multiple
of these objects parallel and all of them can share a single physical
EV3 device. You can also build complex robots with more than one EV3
device and control these robots easily by a single python program.import ev3_dc as ev3

with ev3.Touch(ev3.PORT_1, protocol=ev3.USB) as touch_1:
    touch_4 = ev3.Touch(ev3.PORT_4, ev3_obj=touch_1)
    voice = ev3.Voice(ev3_obj=touch_1, volume=100)

    touched_1 = touch_1.touched
    touched_4 = touch_4.touched
    if touched_1 and touched_4:
        txt = 'both sensors are touched'
    elif touched_1:
        txt = 'only sensor 1 is touched'
    elif touched_4:
        txt = 'only sensor 4 is touched'
    else:
        txt = 'none of the sensors is touched'

    voice.speak(txt).start(thread=False)Some remarks:Connect two touch sensors, one at port 1, the other at port 4 and
connect your EV3 device and your computer with an USB cable.ClassEV3and all its subclasses support the with statement.touch_4 and voice use the connection of touch_1. This is done by setting
keyword argumentev3_obj=touch_1.If you have more than a single EV3 device connected via USB, this
program will fail. To handle this special case identify the device
by using keyword argument host, e.g.ev3.Touch(ev3.PORT_1, protocol=ev3.USB,host='00:16:53:42:2B:99'). For protocol
BLUETOOTH keyword argument host is mandatory.Methodspeak()returns a thread_task.Task object, which we
start threadless.This program depends on the toolffmpegand you need to have it installed on your computer.Readev3-dc.readthedocs.iofor more details.