NRF52 pin RESET

RE: NRF52 pin RESET

Wojtek — Thu, 30 Jun 2016 09:43:38 GMT

If you dont want to use reset, just leave this pin floating - as long as you don't explicitly enable reset pin, it won't work. If you want to use it, don't leave it floating - use external pull-up.

RE: NRF52 pin RESET

energy — Thu, 30 Jun 2016 08:49:13 GMT

Hi,

Do you recommend anything on the reset pin if there is no switch ? I have only a wire that go to a testpad ? Is the internal pull-up enough ? Is there any need for an external pull-up ?

On my product it will be powered directly by a CR2032 or CR123A battery in internal LDO mode

Thanks

RE: NRF52 pin RESET

Vincent — Thu, 30 Jun 2016 02:55:31 GMT

Hi, May I ask the enable reset pin web site link again because these link are gone now. Thanks

RE: NRF52 pin RESET

Siddarth — Tue, 17 May 2016 09:11:17 GMT

But what is the default state for reset pin? The registers PSELRESET are set to 0xffff_ffff at reset so GPIO P0.21 is not registered as reset pin by default.

So how can the hardware reset be guaranteed? How should I design the circuit if I want to reset it no matter what the state of the software of flash is?

RE: NRF52 pin RESET

Øyvind Karlsen — Tue, 21 Jul 2015 13:12:24 GMT

Not as long as you set this in firmware.

RE: NRF52 pin RESET

oliverhu — Tue, 21 Jul 2015 13:10:33 GMT

hi Oyvind thank you very much So I don't need to add a pull up resistor before the switch right?

RE: NRF52 pin RESET

Øyvind Karlsen — Tue, 21 Jul 2015 10:32:50 GMT

There is configurable internal pull-up and pull-down on all GPIO pins, see this infocenter page.

RE: NRF52 pin RESET

oliverhu — Tue, 21 Jul 2015 09:44:21 GMT

Yes, I have checked the file before, but in this case the Switch is just connected to other MCU rather than nrf52. so I still wonder whether there is an internal pull-up resistor

RE: NRF52 pin RESET

Øyvind Karlsen — Tue, 21 Jul 2015 09:36:33 GMT

Hi,

If you check the design files for the nRF52 preview DK you can see that SW5(P0.21/RESET) is connected like this:

So yes, you should connect a pull up resistor.

Remember that you also need to enable reset, see this section in the infocenter.

Best regards,

Øyvind