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.
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.
Just be very careful that the reset trace from the button to the IC is not too long. nRF51 likes to pick up noises on the reset line.
If you have a long (more than 1 inch) reset line, you need to put a strong pull up (1K or 470) as close as possible to the IC (in less than 100mil distance). Layout is not a given.
I have raised this issue to Nordic a while ago. I guess I cannot say this is an issue, which is a common practice when you are dealing all other micros. Let's call it "Be Aware".
Thanks, Paul. I will keep an eye out.
It's a schmidt trigger. The internal pull up is ~47kOhm.
-H
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