nRFgo Studio won't recognize my nRF52 board and Keil uVision JLink error

[rugarcia]

Hi,

I have an nRF52 dev board (PCA10040). I have been using this board for measuring current. I am using the Keil tools.

Yesterday I made a change to main.c in the "ble_app_hrs" example (SDK 0.92). I was able to flash my application last night. Today I am having problems. Refer to symptoms below:

1. I can build the application code using Keil but when I try and flash the code I get JLink - Cortex-M Error No Cortex-M SW Device-Found. uVision Error: Flash Download failed- Target DLL has been cancelled.

2. When I run nRFgo Studio and select the nRF52 development board I get a "No device detected". I also have an nRF51 development dongle and using nRFgo I can see the device without any problems. I am only plugging in one nRF device at a time to avoid any sort of conflicts.

Thanks,

Rudy

[MartinBL]

Hi. Can you please try this with this .bin-file? Also make sure that you have the latest Segger J-Link drivers.

[rugarcia]

I put the board in bootloader mode and loaded the bin file. I still can't connect to the board after power cycling. I have version 4.98c of the Jlink windows software. This is not the latest version but I don't think this is the problem because I can connect to another PCA10400 board without any issues.

I was able to connect to another PCA10400 board and I am able to flash the part on that board using both Keil and nRFgo.

Do you think the board is damaged?

[MartinBL]

Yes, this is strange. That error usually indicates that a nRF5x (or devkit) is not present or that it does not have power. Can you measure if the nRF52 IC is powered with a volt meter. Here are two relevant links: 1 & 2.

If you still can't figure this out please contact us at our support portal and we will see what we can do for you.

[rugarcia]

I measured the nRF52 voltage and it was at 0.8V!!

I was using this dev board to measure current and I had cut a trace that isolated the nRF52 power. Under normal conditions I have this connected my SMU ammeter. I just realized that the SMU was powered down and therefore not able to close the circuit. After enabling the ammeter or shorting the current measure pins I can communicate with the device and flash it.

Problem solved!