machine
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 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 micropython.alloc_emergency_exception_buf
for how to get around this limitation.
If you are using a WiPy board please refer to machine.TimerWiPy <machine.TimerWiPy>
instead of this class.
Construct a new timer object of the given id. Id of -1 constructs a virtual timer (if supported by a board).
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.
Timer.deinit()
Deinitialises the timer. Stops the timer, and disables the timer peripheral.
Timer.ONE_SHOT Timer.PERIODIC
Timer operating mode.