Improvements are:
- Default period is 1000ms with callback disabled.
- if period is not specified then it's not updated (previously, if period
was not specified then it was set to -1 and running the timer callback as
fast as possible, making the REPL unresponsive).
- Use uint64_t to compute delta_ms, and raise a ValueError if the period is
too large.
- If callback is not specified then it's not updated.
- Specifying None for the callback will disable the timer.
Signed-off-by: Damien George <damien@micropython.org>
This commit adds an implementation of machine.Timer backed by the soft
timer mechanism. It allows an arbitrary number of timers with 1ms
resolution, with an associated Python callback. The Python-level API
matches existing ports that have a soft timer, and is used as:
from machine import Timer
t = Timer(freq=10, callback=lambda t:print(t))
...
t = Timer(mode=Timer.ONE_SHOT, period=2000, callback=lambda t:print(t))
...
t.deinit()
Damien George