from microbit import *

#motors
pinMotorLeft = pin12
pinMotorRight = pin13
pinMotorLeft.set_analog_period(10)
pinMotorRight.set_analog_period(10)

#line tracking sensor
pinGroundLeft = pin0
pinGroundRight = pin1

def clip(v,vmin,vmax):
    if v > vmax: v = vmax
    if v < vmin: v = vmin
    return v

def setLeftSpeed(v):# v from -100 to 100
    v = clip(v,-100,100)
    pinMotorLeft.write_analog(150+v)

def setRightSpeed(v):# v from -100 to 100
    v = clip(v,-100,100)
    pinMotorRight.write_analog(150-v)

standBy = True

while True:
    if button_a.was_pressed():
        standBy = not(standBy)
        if standBy:
            setLeftSpeed(0)
            setRightSpeed(0)

    if not(standBy):
        #test line tracking sensors
        print((pinGroundLeft.read_analog(),pinGroundRight.read_analog()))
        # dark = 750, white = 50
        
        if(pinGroundLeft.read_analog()>550):
            setLeftSpeed(-10)
            setRightSpeed(10)
        elif(pinGroundRight.read_analog()<250):
            setLeftSpeed(10)
            setRightSpeed(-10)
        else:
            setLeftSpeed(20)
            setRightSpeed(20)

    sleep(100)