nrf51822 can't reset with SWDIO/nReset pin occasionally

RE: nrf51822 can't reset with SWDIO/nReset pin occasionally

Kenneth — Tue, 07 Dec 2021 14:06:32 GMT

Hello,

My suggestions to try to narrow down the root cause is:

- Try to add NRF_POWER->RESET=1; in start of main(), check if you are able to recreate the issue.

- Try to add a 1Mohm resistor between SWDIO and GND, check if you are able to recreate the issue.

Both of the above will affect the pin reset, and if one of the above solve the issue I will be able to speculate a bit more what is the root-cause.

Kenneth

SimonYao — Tue, 07 Dec 2021 07:41:32 GMT

Hi：

Schematic is as follows, BT_RST is controlled by a push-pull GPIO output(3.3V) of MCU.

Kenneth — Mon, 06 Dec 2021 14:37:07 GMT

Hello,

Can you share a schematic snippet of your circuitry connected to SWDCLK and SWDIO?

Also, can you in start of main() enable NRF_POWER->RESET=1; to make sure pin reset is enabled in debug mode?

Kenneth