Python library for the Maqueen Plus robot developed by DFRobot.
This library is a python version of the one proposed by DFRobot used for block coding.
This version has been developed for students to let them play and enjoy coding this nice little robot.
Link to DFRobot page : [https://www.dfrobot.com/product-2026.html]
- Create robot object
Instantiate the robot object
import microbit
import lib_robot_maqueen as mqn
import time #can be removed if not used
mq = mqn.MaqueenPlus()Move the robot along 4 axis :
- F -> forward
- B -> backward
- L -> left
- R -> right
Function definition :
def move(speed, dir):
"""
speed(pwm) : 0 -> 255
dir(string) : "F" or "B" or "L" or "R"
"""Example :
mq.move(70, "F")
time.sleep(1) #wait for 1s
mq.move(70, "R")To move the robot you can also use the motorControl method.
Function definition :
def motorControl(self, mot, dir, spd):
"""
mot left: MT_L ; mot right: MT_R
dir (forward): 1; dir (backward): 2
spd max: 255; stop: 0
"""Example :
mq.motorControl(mq.MT_L,2,50)
mq.motorControl(mq.MT_R,2,70)MaqueenPlus is equipped with wheel encoders. The function goto uses the wheel encoders to turn or move the robot over an exact number of encoder ticks:
- F -> drive a number of encoder ticks forward
- L -> turn left for a number of encoder ticks
- R -> turn right for a number of encoder ticks
Function definition :
def goto(self, dir, spd, dist):
"""
mot left: MT_L ; mot right: MT_R
dir(string) : "F" or "L" or "R"
spd max: 255; stop: 0
dist: the number of encoder ticks the robot should move
"""Example :
# drive forward with PWM speed 200 for 400 encoder ticks
mq.goto("F", 200, 400)
# turn left with PWM speed 70 for 144 ticks (about 180 degrees)
mq.goto("L", 70, 144)Stop the robot
Function definition:
def stop(self):
"""Stop the robot
"""Example:
mq.stop()You can move three servos with the version of the library, S1, S2, S3.
Function definition:
def servo(self, number, angle):
"""Move a servo for a given angle
Args:
number (int): number of the servo to move
angle (int): rotating angle (min=0 max=180)
"""Example:
mq.servo(mq.S3,90)
time.sleep(1)
mq.servo(mq.S3,0)Read line tracking sensor state. Not all the functions proposed by DFRobot have been implemented. It is up to you to do so.
Function definition:
def getLine(self):
"""Read line tracking state
Returns:
dictionary of [int]: 0 : white / 1 : black
valid keys for the dictionary are: "L3", "L2", "L1", "R1", "R2", "R3"
"""Example:
#Read line tracking sensor state
line = mq.getLine()
print(line["L1"])
print(line["R1"])Get the distance between the robot and an object. An optional argument maxDist was added so you can choose the range of the sensor, which can be important to limit delays in your program. The default setting is 0.4 meters.
Function definition:
def ultrasonic(self,maxDist=0.4):
"""Get the distance between the robot and an object.
Args:
[float, optional] The maximum distance in meters
If function is called with no arguments, defaults to 0.4
Returns:
[float]: distance to the object if one is detected, else max value.
"""Example:
distance = mq.ultrasonic()
distance = mq.ultrasonic(0.8)Get the linear speed of a given motor. INFO : This method has no been tested yet but you can test it and set an issue for feedback.
Function definition:
def motorSpeed(self, mot):
"""Get the linear speed of a given motor
Args:
mot (int): object attribute define in the constructor (MG, MD)
Returns:
[type]: [description]
"""Example:
mq.move(70, "F")
time.sleep(1) #delay is necessary. Otherwise the robot read the speed before the motor started.
spd = mq.motorSpeed(mq.MT_L)
display.show(str(spd))
time.sleep(5)
mq.stop()Turn on/off the rgb light of your choice with the color you want.
-
RGB LED choice: RGB_L : left led, RGB_R : right led, RGB_ALL : both leds
-
Color choice: RED, GREEN, BLUE, YELLOW, PINK, CYAN, WHITE, OFF
Function declaration:
def RGBLight(self, rgbshow, color):
"""Turn on/off the rbg light of your choice with the color you want.
Args:
rgbshow (int): rgb light object attribute defined in the constructor :
RGB_L : left led,
RGB_R : right led,
RGB_ALL : both leds
color (int): color of the led:
RED,GREEN,
BLUE,YELLOW,
PINK,CYAN,
WHITE, OFF
"""Example:
mq.RGBLight(mq.RGB_L,mq.RED)Read the values of the wheel encoders
Function definition:
def getEncoders(self):
"""Read the values of the wheel encoders
Returns:
[tuple of 2 int's]: Value of the left encoder and right encoder
"""Example:
encoders = mq.getEncoders()
print(encoders[0])
print(encoders[1])Reset the values of the wheel encoders to 0
Function definition:
def clearEncoders(self):
"""Reset the values of the wheel encoders to 0
"""Example:
mq.clearEncoders()- Version 1.0: Initial version
- Version 2.0: Compacted code style (short variable names, delete unnecessary space characters) to work around memory constraints and find space for adding functionality. Added goto function for moving the robot with use of the decoders. Added optional maximum distance argument to the ultrasonic function. Should still work with the micro:bit V1. if more functions to this library are added, you will probably need to equip your Maqueen Plus with the micro:bit V2. I am considering making a separate version of this library for the micro:bit V2