EMU_GetFirmwareString: Insufficient data read when trying to read the string length.

[TTk]

Hello 

I was using the NRF52840 dev kit as J-link to develop a custom board. at first was working, i uploaded a blink code to it then i modified the libry from gpio.h to boards.h and ran and example code but after the uploaded one led stays constantly on and the J-Link dosen't connect again. i'm using segger embedded studio.

this is the error

Connecting ?J-Link? using ?USB?
Loaded /Applications/SEGGER Embedded Studio for ARM 6.40/bin/libjlinkarm.dylib
EMU_GetFirmwareString: Insufficient data read when trying to read the string length.
 Insufficient data read when trying to read the string length.
Cannot connect to J-Link

[TTk]

i think the custom board is bad, i used another custom board, and it worked

[Jared]

Hi,

Ok, that's great. Did you have any further questions regarding this problem?

regards

Jared

[TTk]

please I really need help understanding the nrf52840 and segger embedded studio. its my first time working with it. if possible can I have a session with you?

[Jared]

Hi there,

Unfortunately, I do not have the capacity for something like this. But fortunately, we have pretty good blog posts and tutorials on how to get started. I see that you're using nRF5SDK for developing your application. Here is some useful guides for getting started;

Getting started with nRF5 SDK and SES (nRF51 & nRF52 Series)

Introduction to Nordic nRF5 SDK and Softdevice

Bluetooth low energy Advertising, a beginner's tutorial

SEGGER Embedded studio – Getting started

best regards

Jared