gw.sleep on battery powered magnet door switch

[Chakkie]

@AWI Thanks. By the way would you care to explain the interrupt index number? or may be a link for explanation?

[AWI]

@Chakkie In a few words.. The ATMEGA has two external interrupts 0 and 1 which are connected to pins 2 and 3. ("-2" translates the pin number to the interrupt number, which is rather confusing as @mfalkvidd meant)

[Chakkie]

@mfalkvidd Thanks for the info. Does DigitalPinTolnterrupt works better?

[Chakkie]

@AWI Thanks this clear thinks up but at the same time also confusing too.

So "-2" activates both 0 and 1 on pin 2 or pin 3 as you mentioned earlier. I always though it represents a pin number.

[AWI]

@Chakkie The function digitalPinToInterrupt(pin) translates the pin number to the attached interrupt like "-2" does but in a reliable and more understandable way.

[Chakkie]

@AWI thanks. this looks like more promising.

[mfalkvidd]

Pull request done for the development version: https://github.com/mysensors/Arduino/pull/441

[siod]

I would like to build the same but I am still very confused now. Could you upload some pictures so I can make myself an image of how you wirde things together?

Also I don´t really understand what happens here: gw.sleep(BUTTON_PIN_Deur - 2, CHANGE, BUTTON_PIN_Post - 2, CHANGE, 86400000);

[AWI]

@siod If you are using a "standard" Atmega328 (pro-mini, etc.) don't make it hard for yourself. This processor has two external interrupts (0 & 1) connected to pins 2 & 3. Taking your line of code gw.sleep(BUTTON_PIN_Deur - 2, CHANGE, BUTTON_PIN_Post - 2, CHANGE, 86400000); the arguments are respectively:

1. Use interrupt "0" (connected to pin 2 is BUTTON_PIN_Deur)
2. Have is fired on change (i.e Rising and Falling)
3. Use interrupt "1" (connected to pin 3 is BUTTON_PIN_Post)
4. Have is fired on change (i.e Rising and Falling)
5. Wake after every 86400000 ms (24 hrs) if no interrupt fired. To be safe you should use 86400000UL (the UL indicating that it is an Unsigned long type)

[siod]

@AWI
Ok thx for explanation, but that means he is using 2 reed switches, right (interrupt at pin2 and int pin3)?

[AWI]

@siod I guess so. But don't ask me why. One should be sufficient to detect if the door is open :smile:

In addition (and for what it is worth). If you use a real low power circuit you can save around a factor 3 on battery lifetime when you get rid of the timed wakeup. The arduino sleeps a lot better when it doesn't have to look at the alarm clock every few ms :zzz:

[siod]

@AWI
yes, makes sense, but how should you do this wihout the wakeup ? I guess this is just the disadvantage one must accept...

[AWI]

@siod The wakeup function can be disabled by setting the timer values to 0 (or omitting it). There is no purpose in the sketch above for what I can see. If you want to have a kind of "hey I am still alive"/heartbeat feature you need to do a little more (e.g. sending battery level)

[172pilot]

@AWI I was going to ask about that.. I dont see any reason to wake up every 24 hours just to go back to sleep again.. I assume the radio doesn't have any reason to send a keepalive or anything? So, you can omit that number, and it will sleep until interrupted? That's cool..

-Steve

[AWI]

@172pilot yes, no reason to wake up. Especially if there is a regular wake-up from interrupt to let the controller know it it is alive

[Chakkie]

@AWI

Thanks for the info. I thought you always have to add the sleep time to the gw.sleep. I will disable the a wake timer by removing the 86400000.

@siod I use one switch for the letterbox and one for the door.

[siod]

well, as you can see, if you don´t know the libraries exactly you accept things as they are or as they seem to be. I wasn´t aware that you can just set the wakeup function to 0. So this said I would like to thank you @AWI for your patience and your willingness of explaining also the most obvious things! :thumbsup:

[treb0r]

The sketch works with both reeds switches (2 windows) but how to integreate it with DS18B20 temp sensor? I also power it with battery, so I would like to check the temp eg every 5min and if it is changed then send the new value to the controler. How to wake up arduino only if any window is opened or temp is changed (after 5 min)
Thanks
treb0r

[dynamite]

@treb0r You can either wake up on the interrupt or on a time period:

bool sleep(int interrupt, int mode, unsigned long ms=0);

interrupt - Interrupt that should trigger the wakeup.
mode - RISING, FALLING, CHANGE
ms - Number of milliseconds to sleep (or 0 to sleep forever).

The sleep method returns true if wake up was triggered by pin change and false means timer woke it up.

[172pilot]

@treb0r the problem is, you need to wake up the arduino to tell the temp sensor to take a new reading, so the best you can do is to trigger on the interrupts for the Windows and then use the timer to wake up and take the temperature reading, and then you'll have to compare to your saved value to decide whether it has been 5 degrees or not, so you can't completely sleep until that happens..