Custom Board nRF52840 Some Pins Not Working

RE: Custom Board nRF52840 Some Pins Not Working

Kaja — Wed, 05 Oct 2022 14:24:12 GMT

What is the components in the red circles?

What happens if you disconnect these components?

Can you share the full schematic?

Best regards,
Kaja

RE: Custom Board nRF52840 Some Pins Not Working

douglas.malnati — Tue, 04 Oct 2022 17:34:24 GMT

Hi, the code you provided results in the same observations as before, that is, pins which aren't functioning.

I am seeing this problem on at least 8 boards of a batch, never seeing any work (I stopped checking new ones after a while). I have even found another pin (0.16) which isn't working (in addition to the others) on the last board I tried.

I am thinking there is a PCB Assembly problem. I am reaching out to JLCPCB to find out more.

If you have any other thoughts on what I could check I would pursue that as well.

Thanks.

RE: Custom Board nRF52840 Some Pins Not Working

Kaja — Tue, 04 Oct 2022 07:13:03 GMT

Hi,

just to rule out any possible reasons for this to be dependent on your fw, can you flash this bare metal example to your board, measure directly on the pad and see if you can measure a toggling signal? You need to set PIN_GPIO to the pin that you want to test. For example for pin 0.07, PIN__GPIO = 7UL. Just add the code to the hello_world sample in Zephyr.

/*
 * Copyright (c) 2012-2014 Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#include <zephyr/zephyr.h>
#include <nrf.h>
//define the pin that you want to toggle here
#define PIN_GPIO  (13UL)
int main(void)
{
  // Configure GPIO pin as output with standard drive strength.
  NRF_GPIO->PIN_CNF[PIN_GPIO] = (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos) |
                                (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos) |
                                (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) |
                                (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) |
                                (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos);
  // Toggle GPIO ON/OFF.
  while (1)
  {
    uint32_t volatile tmo;
    tmo = 10000000;
    while (tmo--);
    NRF_GPIO->OUTSET = (1UL << PIN_GPIO);    
    tmo = 10000000;
    while (tmo--);
    NRF_GPIO->OUTCLR = (1UL << PIN_GPIO);  
  }
}

How many boards are you seeing this issue on? What percentage?

Best regards,

Kaja

RE: Custom Board nRF52840 Some Pins Not Working

douglas.malnati — Fri, 30 Sep 2022 14:57:13 GMT

Hi,

Here are the gerbers.

devzone.nordicsemi.com/.../BikeControlBoardNRF_2D00_5v_2D00_gerbers.zip

[quote userid="77059" url="~/f/nordic-q-a/92462/custom-board-nrf52840-some-pins-not-working/388703"]Does you the code that worked on the other board not work at all, our is it just the four pin's?[/quote]

Just those 4 pins aren't responsive to software. The code is running otherwise. Other pins are responsive and work as before.

[quote userid="77059" url="~/f/nordic-q-a/92462/custom-board-nrf52840-some-pins-not-working/388703"]Does your code work on our DK?[/quote]

I didn't try. But it does work on another custom board, and an earlier version of the software worked on the Adafdruit nRF52840 Feather (I subsequently moved to a custom board as development continued).

To give an example of what stopped working - I have (AC19 / 0.25) configured to be UART0 TX in my overlay file and that works in my old custom board. Moving to the new custom board, same configuration, same nRF52840 pin, but the signal isn't measurable at the exposed header.

If I reconfigure my overlay to route UART0 TX to a different pin (L1 / 0.06), I can measure that signal there.

The software is no different between the two configurations.

Thanks.

RE: Custom Board nRF52840 Some Pins Not Working

Kaja — Fri, 30 Sep 2022 09:00:59 GMT

Hi Doug,

can you upload the HW files, altium or gerber?

Does you the code that worked on the other board not work at all, our is it just the four pin's?

Does your code work on our DK?

Best regards,
Kaja