What really sleep() do please ?

[DenisJ]

Hi there all,
I just finish a simple node using a barebone Atmega328p.
I program the bootloader MiniCore at 8Mhz internal clock.
I use a BME280 for temp/humidity and RFM69HC for radio.
All work great

Now I'm on the software part of sleep.
I just use Sleep(30000) in order to test it.
What I receive in the log(parser) is:

Sleep node, duration 30000 ms, SmartSleep=0, Int1=255, Mode1=255, Int2=255, Mode2=255
Set transport to sleep
Node woke-up, reason/IRQ=-1 (-2=not possible, -1=timer, >=0 IRQ)
Set transport to standby
Sent Message ...etc...

So I wonder what sleep() do please ? ...it use a watchdog internal timer in order to wake up ?
I have try to use a "LowPower.h" lib but the compiler give me an error:

multiple definition of `__vector_6'

...like already have this piece of code in the MySensor lib.

So if I understand the watchdog internal timer is the best solution to make sleep all strange thinks inside Atmega328p.
Is I still understand it can't do it more than 8sec.

Can anyone please help me to understand ?

Thanks a lot
Denis

[Yveaux]

@DenisJ MySensors implements sleep() for AVR using the watchdog. As you know, the watchdog can only sleep for at most 8 seconds, so long sleeps are divided into smaller watchdog sleeps by MySensors. Sleeping for eg 30 seconds is divided into 3x8 seconds, 1x 4 seconds and 1x2 seconds. This is all done by the library, in the single call to sleep() without you needing to worry about it

[DenisJ]

@Yveaux said in What really sleep() do please ?:

Sleeping for eg 30 seconds is divided into 3x8 seconds, 1x 4 seconds and 1x2 seconds.

Whoau... this is exact what I was think to do
But if MySensors is do this in automatic... well it's wonderful

Do you know ... is do an automatic sleep also for the RFM69 please ?
Thanks a lot.
Denis

[Yveaux]

@DenisJ yes, it does not depend on the radio, but on the arduino platform

[DenisJ]

Ok great
Thanks a lot again
Denis