nRF52840 PDK to external board programming

[Labuka]

I'm using the P20 connectors in nRF52 PDK to flash my custom nRF52832 board.

The connections are like this:

SWDIO ----> SWDIO

SWDCLK ---->SWDCLK

VTG ------> VDD

GND DETECT, GND ----> GND

I've powered up the custom board externally. I'll attach a screenshot of the error I'm receiving. Is the connections I've given correct? or Is there any workarounds for solving this problem. nrfjprog is also throwing an error as JLINKARM_DLL_ERROR. 

[Håkon Alseth]

Hi,

 

It is recommended that you short "VDD_NRF" to "VTG" on P20, to force the segger to  use this port for programming, and power your external board from the nRF5x-DK.

Once this is done, you can connect SWDIO+SWDCLK to your target, in addition to the VDD_NRF and GND.

 

What does the output of Jlink Commander show if you try to connect using this tool?

Do you have other custom boards that behave similar?

 

Best regards,

Håkon

 

[Vijay]

If we short the VDD_nRF and VTG pins, where should the custom boards' VDD be connected? Should the board be powered separately?

Thanks

-vivenkat

Edit 1: My connections are as follows:

On P20,
VDD_nRF and VTG are shorted
VDD is used to power the custom Nordic board

SWDIO and SWDCLK in nRF52 DK to SWDIO and SWDCLK on the custom Nordic board

One of the GND pins from the DK to the custom board.

I have the same error as Labuka. Any help would be gladly appreciated!

-vivenkat

[Labuka]

Hi,

I gave the connections exactly as you described but still I'm facing the same issues. I'll post the logs for reference.

[Håkon Alseth]

Could you check the current consumption of your external board?

You haven't cut SB9 on a previous occasion and not remembered to place a jumper cable on the "nRF current measurement" header?

 

Best regards,

Håkon 

[Vijay]

"When shorting VTG->VDD_NRF (or pin VDD), you tell the board to use P20 as the target debug. Your external board, connected to P20 (1x8 header), should still be powered" - where should this command be given ?

On my DC power supply, the current reading is around 94 mA. I have a pca10040 Atmel IC and I am using it to program a nRF52810. The display on my JLink commander and nRFgo studio is the same what Labuka posted.

Thanks very much for your reply!

-vivenkat  

[Håkon Alseth]

Did you reverse the polarity? 94 mA is very high. It should draw a couple of milliamps when the chip is blank.

I'd recommend that you check the connections and look for shorts on your external board.

[Vijay]

I have two custom boards and both of them draw approx. 95 mA when supplied 3.3 V. The board was designed with the reference schematic in mind. Can the programmer IC draw that much current?

-vivenkat