Using RTC INT

Stuck? We'll be happy to help!
Post Reply
duandv
Posts: 1
Joined: Wed May 06, 2020 3:42 pm

Using RTC INT

Post by duandv » Wed May 06, 2020 4:19 pm

Dear Mrs/Mr
I want to use the RTC's interrupt function ( minute timer interrupt) of my Maxi Automation. I find on the Maxi Automation pin-out datasheet that RTC INT is connected to port PJ7 ( AVR pin 79). But the PJ7 is a pure input/output ( not INTx or PCINTx). So how to catch the RTC interrupt ?
I also check on the AVR board and find one pad ( for soldering) named RTC/INT but it is not really connected to PJ7. Can I solder this pad to port PD3 ( controlino pin header INT0) in order to catch the RTC Interrup ? If yes which side of this pad is correct?
Expect your soon reply
Regards
D.V.Duan

User avatar
Jarda
Posts: 45
Joined: Fri Dec 14, 2018 10:52 am

Re: Using RTC INT

Post by Jarda » Mon May 18, 2020 11:11 am

Hello,

yes, you can use this pad marked RTC/INT. Pad close the the part of the text "RTC" (upper one when text is readable) is going to RTC output.

But there is also internal pull-up connected to +5V is on the board on the RTC output and with Internal pull down of the Interrupt input it will make divider so there will be maximum 2,8V on the processor pin. So it will be not proper LOG HIGH there, but shall work ;) .

BUT signal from RTC is also at CONTROLLINO MAXI connected to PJ4 - PCINT13 (in parallel with PJ7), which is not Arduino supported interrupt, but if you are able write your code in the way that it is interrupt (see for example https://playground.arduino.cc/Main/PinChangeInterrupt/ ) you can also use this without HW modification.

Regards
Jarda

Post Reply