Custom NRF51822 board Not showing in nrfgo

[Greg Winn]

Hello, I have a custom board (was built using the Nordic schematics provided with the Smart Beacon Kit). I am using J-Link LITE to try and program the board.

The board has power and I am able to connect the J-Link Lite. The J-Link Control Panel shows the target voltage and is "green".

When i launch nrfgo studio to write my bootloader it just says "No Device Detected".

Again, this is a custom board with a brand new NRF51822 chip.

Please let me know if you need any more detail! Thanks!

After adding the 100k Pulldown resistor to the SWDCLK. A 100k Pullup on SWDIO and corrected the 16Mhz crystal caps to 18pF (up from the shown 12pF).

[Nguyen Hoan Hoang]

Try to add a 100K pulldown on the SWCLK near the chip.

[Greg Winn]

Thanks Nguyen, I added a 100k pulldown to the SWDCLK but with no luck. I have added a screenshot of NRFGo and the J-Link window so you can see more detail.

[Greg Winn]

Nguyen, I am seeing mixed results now... After disconnecting everything and reconnecting it I am seeing NRFGo to read the board! But what i am now getting is an issue with the J-Link ARM DLL.

"An error condition was detected in the JLinkARM DLL"

[Nguyen Hoan Hoang]

Try to add another pullup this time on the SWDIO. I guest your PCB is noisy. Try also add bypass caps. Skip the pullup for now. I just saw something on your screen. You can't just flash in your app like that. You need first flash in the softdevice. I see that you didn't have the softdevice. It has to be flashing first.

[Greg Winn]

OK so to be clear, I am going to keep the 100k pulldown on the swdclk and try to flash the softdevice. Is there a default hex I should use for this in the SDK?

[Nguyen Hoan Hoang]

Yes, keep the Pulldown. That is what makes your jtag working. The softdevice comes from the S110, s120 or whatever you want to use. You download it from nordicsemi.com. The hex file is in there. That is the first thing you need to flash in before anything else.