External Programming with nRF5-DK P20

[DanKA]

Hello everyone,

i know that there are many similiar questions on the DevZone but i am not able to get it work and i dont uderstand it yet. I want to flash a custom board.

I connect the nRF5-DK to the custom board as the following:

• Custom Board powered with 3V coin cell
• P20 Pin 2 VDD to VDD of custom board
• P20 Pin 4 SWDIO to SWDIO of custom board
• P20 Pin 5 SWD CLK to SWD CLK of custom board
• P20 Pin 8 GND DETECT to GND of custom board. Also tried to use GND of P13  or both. As shown in other questions.

When i use nRFgo Studio , always the internal nRF is flashed. I know the priority is as follows:

• If target power (3V3) is detected on P19 (= some board is attached and powered) it uses that as target, nothing is sent to P20 or internal nRF52 chip.
• If nothing detected on P19 but target power is visible on P20 then it targets this interface (not the internal nRF52 chip).
• If P19 and P20 seems to be unpowered then SEGGER J-Link OB target's built-in nRF52 chip on the board

I applied 3,0 to 3,3 V to P20.2 and P20.8 (just the voltage, no custom coard) and still the internal chip was succesfully flashed. In that case expected something like a failure. What would you expect here?

On Software side i start with the blank blinky from the sdk. I modified pca10040.h to be suitable with my custom board. One LED is common for both (nRF-DK and custom) so that i know which chip was used.

Do you have any suggestions or guaidance? I want to use P20 as i do not have the connectors for P19 yet.

Edit: I did the test with the external voltage because i would like to indicate, if my custom board has a failure. (Eg Board is powered up, but faulty --> error while flashing)

Kind regards

DanKa

[Duncan Xu]

I set up the wire according to your schematic on the right, and had the same issue in nrfgo studio, no device detected. Can you tell me how you make it work with a little bit more details?

Appreciate it. 

[DanKA]

Hi,

I can confirm that this schematic works
(physically wired P20:GND Detect --> P1:GND and then P1:GND -->Custom Board:GND) :

Unfortunately, I have no further details to add. As I mentioned in my post, there was soldering issue. I was able to use all functions of the device after resoldering.

Have you tried nrfjprog and J-Link commander?

[Anne van Rossum]

Hakon What's actually the difference between the first setup and the second? In other words, between VDD nRF (pin 1) and VDD (pin 2). Does the former provide more power to an external board? I couldn't find it in https://infocenter.nordicsemi.com/pdf/nRF52_DK_User_Guide_v1.2.pdf where actually pin 2 is labelled RESET in section 6.1. Hardware Drawings.

[Anne van Rossum]

Ah, never mind! It's just the same when nothing has been changed. I see now in Figure 7. Power supply circuitry. It's meant to be able to current measurements by adding R6 and cutting SB9 as described in 6.9.1 and 6.9.2.

[Santosh Kumar]

Hi,

I have this exact setting for a nRF52810 custom board programmed from nRF52840 DK.

But every time, Keil programs the chip in the DK and doesn't recognize the custom board.

Any hints on this?

Thanks,

Santosh