Hi,
I am trying to run/debug my code in the nRF52840 on my custom board. For that, I connect 4 signals from P20 to my board: VDD nRF to VDD, GND DETECT to GND, SWD IO to SWDIO, and SWD CLK to SWDCLK. I also short pins 2 & 3 of P20 (VDD nRF with VTG), and GND DETECT to the development kit board GND. I have soldered to short SB47. I am powering only the DK board from the USB.
When connecting the USB I see one of the LEDs on my custom board going on, then turning off. I have checked the voltages, and the custom board receives VDD=3 V and GND. CLK is to 0, and SWDIO to 3V.
Then I build and launch the code from my project in SEGGER, and I get this error:
Connecting ‘J-Link’ using ‘USB’ Connecting to target using SWD Loaded C:/Program Files/SEGGER/SEGGER Embedded Studio for ARM 3.34a/bin/JLink_x64.dll Firmware Version: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan 12 2018 16:05:20 DLL Version: 6.30e Hardware Version: V1.00 Target Voltage: 3.300 Device "NRF52840_XXAA" selected. connect failed Failed to connect to target. No idcode detected. Please check connection and Target Interface Type
The project I created by copying the simple uart example in \examples\peripheral\uart\pca10056\blank\ses to an equivalent relative path, then editing the project to have a different name, and edited it to look at pin definitions in custom_boad.h.
I have also tried to program the chip in the DK as an external chip and I get the same result. For this, I soldered 2 cables to P25.2 and P25.4 and connected them to P20 signals SWDIO and SWD CLK. Since SB47 is soldered to short, it should be treated as if an external chip, but the output I get is exactly the same.
What I am missing? Perhaps I need to do or bypass some reset pin or something like that? I really cannot think of anything else to try. Thank you very much.
