"""
Capstone Team Project. Contains the lower-level code for (only)
the devices used in this Capstone Team Project.
Winter term, 2019-2020.
"""
###############################################################################
# STUDENTS: *** Do NOT change ANYTHING in this module. ***
###############################################################################
import ev3dev.ev3 as ev3
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# Motor
###############################################################################
class Motor(object):
"""
Controls a single EV3 Motor. Our robot has 2 "large" motors for the wheels
and a "medium" motor to control the arm/claw.
"""
def __init__(self, port, motor_type='large'):
"""
Constructs a Motor based on the input parameters. Valid ports:
'A', 'B', 'C', or 'D'
Our "large" motors are in ports "B" and "C"
Our "medium" motor is in port "A"
Valid motor_types: "medium" or "large"
---
:param port: Letter on EV3 brick where motor connects
:type port: str
:param motor_type: Motor types are either "medium" or "large"
:type motor_type: str
"""
if motor_type == 'large':
self._motor = ev3.LargeMotor('out' + port)
else:
self._motor = ev3.MediumMotor('out' + port)
def turn_on(self, speed):
"""
Turns on the motor at the requested speed. Valid speeds:
-100 up to 100
For example:
-100 full speed in reverse
-50 slow reverse
0 coast to a stop
30 slow forwards
60 pretty fast forwards
100 max speed forwards
---
:param speed: Duty cycle percentage for motor
:type speed: int
"""
self._motor.run_direct(duty_cycle_sp=speed)
def turn_off(self, stop_action="brake"):
"""
Stops the motor.
Note: turn_off is similar to turn_on(0), but turn_off
tries to stop the motion a bit faster using the brake option.
"""
self._motor.stop(stop_action=stop_action)
def get_position(self):
"""
Returns the position of the motor since the last reset.
Units are in degrees
:return: Position of the motor in degrees
:rtype: int
"""
return self._motor.position
def reset_position(self):
"""
:return:
"""
self._motor.position = 0
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# TouchSensor
###############################################################################
class LowLevelTouchSensor(object):
"""
An object associated with a physical Touch Sensor that is plugged into
a port (1, 2, 3, or 4). It can report whether or not the Touch Sensor
is pressed or not.
"""
def __init__(self, port=None):
"""
The port must be 1, 2, 3, 4, or None, where None means to attempt
to autodetect a port into which a physical Touch Sensor is plugged.
---
:param port: The port (1, 2, 3, or 4) into which a Touch Sensor is
plugged, or None to attempt to autodetect such a port.
:type port: int | None
"""
if port not in (1, 2, 3, 4, None):
message = "The port for a TouchSensor must be\n"
message += "1, 2, 3, or 4, or None to attempt\n"
message += "to autodetect a physical Touch Sensor."
raise ValueError(message)
if port is not None:
self._touch_sensor = ev3.TouchSensor('in' + str(port))
else:
self._touch_sensor = ev3.TouchSensor() # Attempt to autodetect
def get_reading(self):
"""
Returns 1 if this the physical Touch Sensor associated with this
TouchSensor is pressed, else returns 0.
---
:rtype: int
"""
return self._touch_sensor.is_pressed # 1 (pressed) or 0 (not pressed)