nrf51822 Minew's Module is not recognized by NRF51DK

[fercholas]

Hi guys

I am trying to program a nrf51822 module but it is not recognized by the development kit.

These are the pins that I am using:

I can not see the module with NRFGo on Windows or on linux with Jlink console.

Any idea?

Thanks in advance!

[endnode]

Hi,

Not sure if I understood correctly your problem but I'm using nRF52 and nRF51 DK boards to flash dozens of custom boards daily and my working set-up through external header P20 is:

• P20 pin 4 for SWDIO
• P20 pin 5 for SWDCLK
• P20 pin 7 for SWD RESET (optional - many designs don't use this and even if they do you can skip it)
• Powering: P20 pin 1 for 3V3
• Ground: any GND pin on the DK (not sure if you can use pin 8 from P20, I use pins explicitly saying GND)

Now key trick: you need to tell to SEGGER J-Link OB (on-board) that it should use P20 neither P19 nor internal connection to nRF5x chip. I do it through simple connection of P20 pins 2 and 3. Again it might work also with other shorts but this is what you are missing I believe.

Cheers Jan

[fercholas]

Hi endnode

Thanks for answering. I have tried with the connection of P20 pins 2 and 3 without results.

• P20 pin 4 for SWDIO
• P20 pin 5 for SWDCLK
• P20 pin 8 for a connection between Modules's ground and NRF51DK's ground.
• P20 2 and 3 shorted.

I am not using P20 pin 1. How do you use it?

Thanks in advance

[endnode]

Hi, hard to say what's wrong then. For me it works even when I play with second nRF5x DK board (if I bridge P20 SWD PINs to standard 10-pin SEGGER connector then I can flash nRF5x chip on the other DK without problems) so it might indicate problems with this one particular custom board. I'm using Pin 1 of P20 (VDD_nRF) to power target board by 3V. Yes, you can use other pins from other headers on nRF5x DK to achieve the same...

Cheers Jan

[fercholas]

Hi,

So, your external board does not have an external supply? .

I am using a C2032 battery to power up the module.

[endnode]

Hi,

Well then you might skip connecting VCC to SH_VTG and instead just short PINs 2 and 3 (VIO and SH_VTG). Also could you use other target board - e.g. another nRF5x DK - and make your SEGGER J-Link OB work with it? Otherwise it can be any kind of HW/SW problem in your set-up (the only help I can provide is ton of pictures and videos how it works for me on several target boards + traces from nrfjprog or SEGGER J-Flash Lite but on WINDOWS;)

Cheers Jan

[Chocol8]

This configuration really works! Thank you su much, Jan! Had this problem for a long time...