Servos & Robotics

# Add the libraries you need
import servo

# Give your pins easy-to-remember names
i1 = set_name("button")
o1 = set_name("gate")
o2 = set_name("open_led")

# ===== Automatic gate =====

# This code block executes only once
setup:
    button = set_input(push_button, active_low)
    gate = set_output(servo, 0)
    open_led = set_output(led)

# This code block executes forever
loop:
    if button == ON:  # when button is ON
        servo_flip(gate, 0, 90, 5, 20)  # 1st press opens, 2nd press closes
    if servo_read_angle(gate) > 45:  # when servo_read_angle(gate) > 45
        open_led = ON  # turn open_led ON
    else:  # otherwise
        open_led = OFF  # turn open_led OFF

An automatic gate with servo_flip: the first press of button opens the gate (0° → 90°), the next press closes it. servo_read_angle(gate) tells the program where the gate is, so open_led glows while it is more than half open. The start angle 0 is in set_output(servo, 0).

# Add the libraries you need
import servo

# Give your pins easy-to-remember names
i1 = set_name("up_button")
i2 = set_name("down_button")
o1 = set_name("arm")

# ===== Crane arm =====

# This code block executes only once
setup:
    up_button = set_input(push_button, active_low)
    down_button = set_input(push_button, active_low)
    arm = set_output(servo, 90)
    servo_increment_till(arm, 90, 180, 5, 20)  # wake-up stretch: 90° up to 180°
    servo_decrement_till(arm, 180, 0, 5, 20)  # then all the way down to 0°
    servo_write_angle(arm, 90)  # back to the middle

# This code block executes forever
loop:
    if up_button == ON:  # when up_button is ON
        servo_increment(arm, 10, 170, 100)  # up 10°, never past 170°
    elif down_button == ON:  # otherwise, when down_button is ON
        servo_decrement(arm, 10, 10, 100)  # down 10°, never below 10°
    wait(100)  # pause here for 100 milliseconds before continuing

A crane arm. At start-up it stretches up with servo_increment_till, down with servo_decrement_till and returns to the middle with servo_write_angle. Then two buttons nudge it up and down 10° at a time — never past 170° or below 10°.

# Add the libraries you need
import ultrasonic
import servo

# Give your pins easy-to-remember names
o1 = set_name("dish")
o2 = set_name("dish2")
o5 = set_name("alert")

# ===== Twin radar scanner =====

# This code block executes only once
setup:
    i3 = set_input(ultrasonic_trig)  # cannot be changed
    i4 = set_input(ultrasonic_echo)  # cannot be changed
    dish = set_output(servo, 90)
    dish2 = set_output(servo, 90)
    alert = set_output(led)
    servo_sync(dish, dish2)  # dish2 copies every move of dish
    servo_scan_on(dish, 0, 180, 5, 30)  # keep sweeping on its own

# This code block executes forever
loop:
    d = distance()  # -1 when nothing is in range
    if d > 0 and d < 20:  # when d > 0 and d < 20
        servo_scan_stop(dish)  # freeze, pointing at the object
        alert = ON  # turn alert ON
    else:  # otherwise
        servo_scan_resume(dish)  # carry on from the same place
        alert = OFF  # turn alert OFF

Twin radar dishes (TinkerPy Mega: the ultrasonic uses i3 and i4). servo_scan_on keeps dish sweeping on its own and servo_sync makes dish2 copy it. When something is closer than 20 cm the scan freezes and alert lights; when it goes away the scan resumes from the same place.

# Add the libraries you need
import motor
import servo

# Give your pins easy-to-remember names
o1 = set_name("left_arm")
o2 = set_name("right_arm")

# ===== Robot dance routine =====

# This code block executes only once
setup:
    o3 = set_output(right_motor_P)
    o4 = set_output(right_motor_N)
    o5 = set_output(left_motor_P)
    o6 = set_output(left_motor_N)
    left_arm = set_output(servo, 90)
    right_arm = set_output(servo, 90)
    servo_sync_reverse(left_arm, right_arm)  # arms always mirror each other

# This code block executes forever
loop:
    robot_control("F", 70, "F", 70)  # forward
    wait(1000)  # pause here for 1000 milliseconds before continuing
    robot_control("B", 70, "F", 70)  # spin left
    wait(600)  # pause here for 600 milliseconds before continuing
    robot_control("F", 40, "F", 90)  # curve left
    wait(1000)  # pause here for 1000 milliseconds before continuing
    robot_control("S", 0, "S", 0)  # stop and wave
    servo_oscillate(left_arm, 90, 30, 150, 5, 15)  # oscillate left_arm from angle 30 to 150, start and stop pos: angle 90
    motor_control_right("F", 70)  # only the right wheel: pivot left
    wait(700)  # pause here for 700 milliseconds before continuing
    motor_control_right("S", 0)  # stop the right wheel
    motor_control_left("B", 70)  # only the left wheel, backwards
    wait(700)  # pause here for 700 milliseconds before continuing
    motor_control_left("S", 0)  # stop the left wheel

A robot dance routine: forward, spin left, curve left, stop and wave, then pivot on one wheel and the other. servo_sync_reverse makes right_arm mirror left_arm while it oscillates. Tune the wait times on your own floor.