Class LegoPort

ev3dev2.port.LegoPort

The ``lego-port`` class provides an interface for working with input and

Declaration

class LegoPort(Device)

Documentation

output ports that are compatible with LEGO MINDSTORMS RCX/NXT/EV3, LEGO WeDo and LEGO Power Functions sensors and motors. Supported devices include the LEGO MINDSTORMS EV3 Intelligent Brick, the LEGO WeDo USB hub and various sensor multiplexers from 3rd party manufacturers.

See the following example for using this class to configure sensors: https://github.com/ev3dev/ev3dev-lang-python-demo/blob/stretch/platform/brickpi3-motor-and-sensor.py

Some types of ports may have multiple modes of operation. For example, the input ports on the EV3 brick can communicate with sensors using UART, I2C or analog validate signals - but not all at the same time. Therefore there are multiple modes available to connect to the different types of sensors.

In most cases, ports are able to automatically detect what type of sensor or motor is connected. In some cases though, this must be manually specified using the mode and set_device attributes. The mode attribute affects how the port communicates with the connected device. For example the input ports on the EV3 brick can communicate using UART, I2C or analog voltages, but not all at the same time, so the mode must be set to the one that is appropriate for the connected sensor. The set_device attribute is used to specify the exact type of sensor that is connected. Note: the mode must be correctly set before setting the sensor type.

Ports can be found at /sys/class/lego-port/port<N> where <N> is incremented each time a new port is registered. Note: The number is not related to the actual port at all - use the address attribute to find a specific port.

Methods

▶ def __init__(self, address=None, name_pattern=SYSTEM_DEVICE_NAME_CONVENTION, ...) override
inherited doc Spin through the Linux sysfs class for the device type and find a device that matches the provided name pattern and attributes (if any).
def __init__(
self,
address=None,
name_pattern=SYSTEM_DEVICE_NAME_CONVENTION,
name_exact=False,
**kwargs,
)
source link
This method overrides ev3dev2.Device.__init__.
Parameters:
class_name: class name of the device, a subdirectory of /sys/class.
For example, 'tacho-motor'.
name_pattern: pattern that device name should match.
For example, 'sensor*' or 'motor*'. Default value: '*'.
name_exact: when True, assume that the name_pattern provided is the
exact device name and use it directly.
keyword arguments: used for matching the corresponding device
attributes. For example, address='outA', or driver_name=['lego-ev3-us', 'lego-nxt-us']. When argument value is a list, then a match against any entry of the list is enough.
Example:
d = ev3dev.Device('tacho-motor', address='outA') s = ev3dev.Device('lego-sensor', driver_name=['lego-ev3-us', 'lego-nxt-us'])
If there was no valid connected device, an error is thrown.
▷ def address(self) @property
Returns the name of the port. See individual driver documentation for the name that will be returned.
@property
def address(self)
source link
▷ def driver_name(self) @property
Returns the name of the driver that loaded this device. You can find the complete list of drivers in the [list of port drivers].
@property
def driver_name(self)
source link
▶ def mode(self) @property
Reading returns the currently selected mode. Writing sets the mode.
@property
def mode(self)
source link
Generally speaking when the mode changes any sensor or motor devices associated with the port will be removed new ones loaded, however this this will depend on the individual driver implementing this class.
▷ def mode(self, value) @mode.setter
@mode.setter
def mode(
self,
value,
)
source link
▷ def modes(self) @property
Returns a list of the available modes of the port.
@property
def modes(self)
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▶ def set_device(self) @property
For modes that support it, writing the name of a driver will cause a new
@property
def set_device(self)
source link
device to be registered for that driver and attached to this port. For example, since NXT/Analog sensors cannot be auto-detected, you must use this attribute to load the correct driver. Returns -EOPNOTSUPP if setting a device is not supported.
▷ def set_device(self, value) @set_device.setter
@set_device.setter
def set_device(
self,
value,
)
source link
▶ def status(self) @property
In most cases, reading status will return the same value as ``mode``. In
@property
def status(self)
source link
cases where there is an auto mode additional values may be returned, such as no-device or error. See individual port driver documentation for the full list of possible values.

Inherited methods

Methods inherited from ev3dev2.Device:
__lt__, __repr__, __str__, device_index, get_attr_from_set, get_attr_int, get_attr_line, get_attr_set, get_attr_string, get_cached_attr_int, get_cached_attr_set, get_cached_attr_string, set_attr_int, set_attr_raw, set_attr_string