Commit ddbcc795 authored by Damien George's avatar Damien George
Browse files

docs: Add quickref info about Servo; improve Servo docs.

parent ce5b5caf
.. _pyb.Servo:
class Servo -- 3-wire hobby servo driver
========================================
Servo controls standard hobby servos with 3-wires (ground, power, signal).
Servo objects control standard hobby servo motors with 3-wires (ground, power,
signal). There are 4 positions on the pyboard where these motors can be plugged
in: pins X1 through X4 are the signal pins, and next to them are 4 sets of power
and ground pins.
Example usage::
import pyb
s1 = pyb.Servo(1) # create a servo object on position X1
s2 = pyb.Servo(2) # create a servo object on position X2
s1.angle(45) # move servo 1 to 45 degrees
s2.angle(0) # move servo 2 to 0 degrees
# move servo1 and servo2 synchronously, taking 1500ms
s1.angle(-60, 1500)
s2.angle(30, 1500)
.. note:: The Servo objects use Timer(5) to produce the PWM output. You can
use Timer(5) for Servo control, or your own purposes, but not both at the
same time.
Constructors
------------
.. class:: pyb.Servo(id)
Create a servo object. ``id`` is 1-4.
Create a servo object. ``id`` is 1-4, and corresponds to pins X1 through X4.
Methods
......@@ -17,22 +39,41 @@ Methods
.. method:: servo.angle([angle, time=0])
Get or set the angle of the servo.
If no arguments are given, this function returns the current angle.
If arguments are given, this function sets the angle of the servo:
- ``angle`` is the angle to move to in degrees.
- ``time`` is the number of milliseconds to take to get to the specified angle.
- ``time`` is the number of milliseconds to take to get to the specified
angle. If omitted, then the servo moves as quickly as possible to its
new position.
.. method:: servo.calibration([pulse_min, pulse_max, pulse_centre, [pulse_angle_90, pulse_speed_100]])
.. method:: servo.speed([speed, time=0])
If no arguments are given, this function returns the current speed.
Get or set the calibration of the servo timing.
If arguments are given, this function sets the speed of the servo:
- ``speed`` is the speed to change to, between -100 and 100.
- ``time`` is the number of milliseconds to take to get to the specified
speed. If omitted, then the servo accelerates as quickly as possible.
.. method:: servo.pulse_width([value])
Get or set the pulse width in milliseconds.
If no arguments are given, this function returns the current raw pulse-width
value.
.. method:: servo.speed([speed, time=0])
If an argument is given, this function sets the raw pulse-width value.
.. method:: servo.calibration([pulse_min, pulse_max, pulse_centre, [pulse_angle_90, pulse_speed_100]])
If no arguments are given, this function returns the current calibration
data, as a 5-tuple.
If arguments are given, this function sets the timing calibration:
Get or set the speed of a continuous rotation servo.
- ``speed`` is the speed to move to change to, between -100 and 100.
- ``time`` is the number of milliseconds to take to get to the specified speed.
- ``pulse_min`` is the minimum allowed pulse width.
- ``pulse_max`` is the maximum allowed pulse width.
- ``pulse_centre`` is the pulse width corresponding to the centre/zero position.
- ``pulse_angle_90`` is the pulse width corresponding to 90 degrees.
- ``pulse_speed_100`` is the pulse width corresponding to a speed of 100.
......@@ -98,6 +98,7 @@ Power related functions
If given no arguments, returns a tuple of clock frequencies:
(sysclk, hclk, pclk1, pclk2).
These correspond to:
- sysclk: frequency of the CPU
- hclk: frequency of the AHB bus, core memory and DMA
- pclk1: frequency of the APB1 bus
......
......@@ -48,6 +48,18 @@ See :ref:`pyb.Pin <pyb.Pin>`. ::
p_in = Pin('X2', Pin.IN, Pin.PULL_UP)
p_in.value() # get value, 0 or 1
Servo control
-------------
See :ref:`pyb.Servo <pyb.Servo>`. ::
from pyb import Servo
s1 = Servo(1) # servo on position 1 (X1, VIN, GND)
s1.angle(45) # move to 45 degrees
s1.angle(-60, 1500) # move to -60 degrees in 1500ms
s1.speed(50) # for continuous rotation servos
External interrupts
-------------------
......
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