/ev3-python3

Use python3 to program your LEGO EV3. Communicate via bluetooth, wifi or USB. Send direct commands.

Primary LanguagePythonGNU General Public License v3.0GPL-3.0

ev3-python3

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. I wrote a blog about this code.

There is no need to boot the EV3 device from a SD Card or manipulate its software. You can use it as it is, the EV3 is designed to execute commands which come from outside.

The code consists of the following modules:

  • ev3.py
    Base class EV3, that represents the LEGO EV3 device.
  • ev3_file.py
    FileSystem, subclass of EV3. Access to EV3's filesystem.
  • ev3_sound.py
    Jukebox, subclass of EV3. Combines sound and LED light effects, plays music.
  • ev3_vehicle.py
    TwoWheelVehicle, subclass of EV3. Precise movements of a vehicle with two drived wheels.
  • task.py
    Organizes tasks. Allows parallel and sequential execution of functions.

Examples

Writing and sending direct commands

This program communicates via USB with an EV3 device (mac-address: '00:16:53:42:2B:99') and plays a tone with a frequency of 440 Hz for a duration of 1 sec.

#!/usr/bin/env python3

import ev3

my_ev3 = ev3.EV3(protocol=ev3.USB, host='00:16:53:42:2B:99')
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)

Its output:

11:48:31.188008 Sent 0x|0E:00|2A:00|80|00:00|94:01:01:82:B8:01:82:E8:03|

This shows the direct command, which was sent to the EV3 device.

Subclasses of EV3 encapsulate direct commands

Class Jukebox of module ev3_sound has a method play_tone, which also plays tones:

#!/usr/bin/env python3

import ev3, ev3_sound

jukebox = ev3_sound.Jukebox(protocol=ev3.BLUETOOTH, host='00:16:53:42:2B:99')
jukebox.verbosity = 1
jukebox.play_tone("a'", duration=1)

This program communicates via Bluetooth and sends a direct command too. Its output:

11:55:11.324701 Sent 0x|0E:00|2A:00|80|00:00|94:01:01:82:B8:01:82:E8:03|