Disable NFC Interrupt

RE: Disable NFC Interrupt

sara — Tue, 25 Jul 2017 05:52:29 GMT

Thanks for your explanation, and essential Q&A from Stefan is a very good post.

RE: Disable NFC Interrupt

endnode — Mon, 24 Jul 2017 08:54:55 GMT

Not really. If you want to use NFC HW peripheral block (e.g. it you expect to be working with reader once antenna enters the field) then no you cannot disable interrupt. If you are optimizing power consumption, there is essential Q&A from Stefan. It's for nRF51 but it's very much applicable for nRF52 as well. There is nothing about NFC but that's only small part, like cherry on top of the cake. If you want to use it, you need to have it active, otherwise disable it. Simple as that.

RE: Disable NFC Interrupt

sara — Mon, 24 Jul 2017 01:46:44 GMT

So what I have do is let device enter SYSTEM ON SLEEP mode and disable HW peripherals, and there is no way to disable NFC interrupt. Is it correct?

RE: Disable NFC Interrupt

endnode — Fri, 21 Jul 2017 10:20:57 GMT

Still the same as any other situation on nRF5x chips: use SYSTEM ON SLEEP mode (WFE/WFI, sd_app_evt_wait()), disabling HW peripherals (+ interrupts) when not needed. If not enough and your use case supports it you can try to use SYSTEM OFF mode with external wake-up by GPIO or NFC (but note that you cannot run internal timers so SD doesn't run any BLE activity etc.)

RE: Disable NFC Interrupt

sara — Fri, 21 Jul 2017 09:19:19 GMT

Understood, but is there any method to save power if user uses NFC to read data?

RE: Disable NFC Interrupt

endnode — Fri, 21 Jul 2017 09:13:45 GMT

I'm afraid you need to wake-up MCU in order to process NFC data flow, only the lowest layer is done in NFC HW peripheral block. So it cannot run with MCU in sleep (SYSTEM ON).