By design, at wake up from deepsleep, the RTC timer will be reset, but
the data stored in RTC memory will not [1]. Therefore, we have to adjust
delta in RTC memory before going into deepsleep to get almost correct
time after waking up.
[1] http://bbs.espressif.com/viewtopic.php?t=1184#p4082
ESP-SDK system_get_rtc_time() returns uint32 and therefore overflow
about every 7:45h. Let's write the last state of system_get_rtc_time()
in RTC mem and use it to check for overflow. This commit require running
pyb_rtc_get_us_since_2000() at least once within 7 hours to avoid
overflow.
Use the machine.deepsleep() function to enter the sleep mode. Use the
RTC to configure the alarm to wake the device.
Basic use is the following:
import machine
# configure RTC's ALARM0 to wake device from deep sleep
rtc = machine.RTC()
rtc.irq(trigger=rtc.ALARM0, wake=machine.DEEPSLEEP)
# do other things
# ...
# set ALARM0's alarm to wake after 10 seconds
rtc.alarm(rtc.ALARM0, 10000)
# enter deep-sleep state (system is reset upon waking)
machine.deepsleep()
To detect if the system woke from a deep sleep use:
if machine.reset_cause() == machine.DEEPSLEEP_RESET:
print('woke from deep sleep')
Initialize RTC period coefficients, etc. if RTC RAM doesn't contain valid
values. time.time() then will return number of seconds since power-on, unless
set to different timebase.
This reuses MEM_MAGIC for the purpose beyond its initial purpose (but the whole
modpybrtc.c need to be eventually reworked completely anyway).
The first argument to the type.make_new method is naturally a uPy type,
and all uses of this argument cast it directly to a pointer to a type
structure. So it makes sense to just have it a pointer to a type from
the very beginning (and a const pointer at that). This patch makes
such a change, and removes all unnecessary casting to/from mp_obj_t.
py/mphal.h contains declarations for generic mp_hal_XXX functions, such
as stdio and delay/ticks, which ports should provide definitions for. A
port will also provide mphalport.h with further HAL declarations.
