How to implement RESET button on nRF51822?

[Michal Zacharias]

I would like to know how to implement reset button on nRF51822. Image of schematic would be very useful, but good explanation should be enough. Thank you in advance.

I already have SWDIO/nRESET (pin 23) connected from ARM programming connector.

[William Grange]

Hi Håkon,

I was planning to use an active-low reset switch in parallel to SWDIO just like Michal describes. The -EK shows 150Ω in series with the switch to ground.

Is the value of the pull-up 13kΩ similar to the GPIO?

Also, can you comment on whether there is an internal capacitor to GND on the reset line or a Schmidt trigger on the reset line's input to de-glitch the transitions?

Thanks, William

[Håkon Alseth]

It's a schmidt trigger. The internal pull up is ~47kOhm.

-H

[Håkon Alseth]

Oh' sorry, did not answer the full post. There is no internal capacitor, other than the stray capacitances that you have in the pad connection and PCB tracks (totals <10 pF-area).

Best regards Håkon