blob: b16ad52d597f5bea364a8827e9d7ae23683236f4 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
.. currentmodule:: machine
.. _machine.Timer:
class Timer -- control hardware timers
======================================
Hardware timers deal with timing of periods and events. Timers are perhaps
the most flexible and heterogeneous kind of hardware in MCUs and SoCs,
differently greatly from a model to a model. MicroPython's Timer class
defines a baseline operation of executing a callback with a given period
(or once after some delay), and allow specific boards to define more
non-standard behavior (which thus won't be portable to other boards).
See discussion of :ref:`important constraints <machine_callbacks>` on
Timer callbacks.
.. note::
Memory can't be allocated inside irq handlers (an interrupt) and so
exceptions raised within a handler don't give much information. See
:func:`micropython.alloc_emergency_exception_buf` for how to get around this
limitation.
If you are using a WiPy board please refer to :ref:`machine.TimerWiPy <machine.TimerWiPy>`
instead of this class.
Constructors
------------
.. class:: Timer(id, ...)
Construct a new timer object of the given id. Id of -1 constructs a
virtual timer (if supported by a board).
Methods
-------
.. method:: Timer.init(\*, mode=Timer.PERIODIC, period=-1, callback=None)
Initialise the timer. Example::
tim.init(period=100) # periodic with 100ms period
tim.init(mode=Timer.ONE_SHOT, period=1000) # one shot firing after 1000ms
Keyword arguments:
- ``mode`` can be one of:
- ``Timer.ONE_SHOT`` - The timer runs once until the configured
period of the channel expires.
- ``Timer.PERIODIC`` - The timer runs periodically at the configured
frequency of the channel.
.. method:: Timer.deinit()
Deinitialises the timer. Stops the timer, and disables the timer peripheral.
Constants
---------
.. data:: Timer.ONE_SHOT
Timer.PERIODIC
Timer operating mode.
|
