nRF52832 Custom Board - RESET stuck low

RE: nRF52832 Custom Board - RESET stuck low

phipi — Mon, 19 Feb 2018 15:28:13 GMT

I think I may have a bad connector. It seems like wiggling the 10pin ribbon cable can cause the issue to appear/disappear.

Thanks for the support.

RE: nRF52832 Custom Board - RESET stuck low

Kenneth — Mon, 19 Feb 2018 09:07:03 GMT

Then I am not sure what the problem might be, I assume the board does operate as expected once you are able to program it? If yes, then maybe you should look at the programmer, how it's connected (GND, SWD pins, VDD), if the power supply range is supported by the programmer, try another programmer, and/or reduce programming speed.

RE: nRF52832 Custom Board - RESET stuck low

phipi — Thu, 15 Feb 2018 14:21:02 GMT

I have been able to program it a few more times since then but it seems like it's very finicky. 90% of the time when I connect the J-Link the reset gets pulled low but the other 10% of the time it works and I am able to program. Without the J-Link the reset is high as expected.

RE: nRF52832 Custom Board - RESET stuck low

Kenneth — Thu, 15 Feb 2018 12:02:13 GMT

Hi, what likely has happened here is that you have programmed an application that enabled pin reset (CONFIG_GPIO_AS_PINRESET defined), and in addition you may have configured P0.21 (pin reset) as output low. This will cause the chip to stay continuously in reset state, preventing it to be re-programmed. The only way to get out of this situation is to force P0.21 high externally, by for instance connect it directly to VDD. This is not an ideal situation, since you are driving an output pin high, but should work for a short time while you can recover the chip using 'nrfjprog -f nrf52 --recover'.