1.. zephyr:code-sample:: servo-motor
2   :name: Servomotor
3   :relevant-api: pwm_interface
4
5   Drive a servomotor using the PWM API.
6
7Overview
8********
9
10This is a sample app which drives a servomotor using the :ref:`PWM API <pwm_api>`.
11
12The sample rotates a servomotor back and forth in the 180 degree range with a
13PWM control signal.
14
15This app is targeted for servomotor ROB-09065. The corresponding PWM pulse
16widths for a 0 to 180 degree range are 700 to 2300 microseconds, respectively.
17Different servomotors may require different PWM pulse widths, and you may need
18to modify the source code if you are using a different servomotor.
19
20Requirements
21************
22
23The sample requires a servomotor whose signal pin is connected to a pin driven
24by PWM. The servo must be defined in Devicetree using the ``pwm-servo``
25compatible (part of the sample) and setting its node label to ``servo``. You
26will need to do something like this:
27
28.. code-block:: devicetree
29
30   / {
31       servo: servo {
32           compatible = "pwm-servo";
33           pwms = <&pwm0 1 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
34           min-pulse = <PWM_USEC(700)>;
35           max-pulse = <PWM_USEC(2500)>;
36       };
37   };
38
39Note that a commonly used period value is 20 ms. See
40:zephyr_file:`samples/basic/servo_motor/boards/bbc_microbit.overlay` for an
41example.
42
43Wiring
44******
45
46BBC micro:bit
47=============
48
49You will need to connect the motor's red wire to external 5V, the black wire to
50ground and the white wire to the SCL pin, i.e. pin P19 on the edge connector.
51
52Building and Running
53********************
54
55The sample has a devicetree overlay for the :ref:`bbc_microbit`.
56
57This sample can be built for multiple boards, in this example we will build it
58for the bbc_microbit board:
59
60.. zephyr-app-commands::
61   :zephyr-app: samples/basic/servo_motor
62   :board: bbc_microbit
63   :goals: build flash
64   :compact:
65