class Timer – virtual periodic / one-shot timer

The Timer class implements a software-managed virtual timer that schedules a Python callback either once (one-shot) or repeatedly (periodic) at a given period. Use it when you want a lightweight cross-port way to run a callback on a schedule – for hardware-level features (PWM channels, input capture, encoder mode, dead-time, break input, etc.) use pyb.Timer instead.

Available on every OpenMV port.

Example – periodic 10 Hz callback:

from machine import Timer

def tick(t):
    print("tick")

tim = Timer(-1)
tim.init(period=100, callback=tick)   # 100 ms = 10 Hz

Example – run a callback once after 2 seconds:

from machine import Timer

def fire(t):
    print("once")

Timer(-1).init(mode=Timer.ONE_SHOT, period=2000, callback=fire)

Constructors

class machine.Timer(id: int = -1, /, *, mode: int = PERIODIC, period: int = -1, callback: Callable[[Timer], None] | None = None)

Construct a virtual Timer. id must be -1 (the only supported value). Any keyword arguments are forwarded to init() so the timer can be configured in a single call.

Methods

init(*, mode: int = PERIODIC, period: int = -1, callback: Callable[[Timer], None] | None = None) → None

Initialise / re-initialise the timer.

• mode selects ONE_SHOT (fire once and stop) or PERIODIC (fire repeatedly).

• period is the period in milliseconds.

• callback is invoked when the timer fires. It receives the Timer instance as its only argument.

deinit() → None

Stop the timer and cancel any pending callback.

Constants

ONE_SHOT: int

Pass to mode so the timer fires once and then stops.

PERIODIC: int

Pass to mode so the timer fires repeatedly at period intervals.