Custom Board Programming

[Alan Ajit]

Dear Nordic

I have custom board(nRF52840) its not detecting through Jlink (from nRF52 DK). 

I tried to connect nRF52840 dongle(using J2 in dongle) with same setup its detected and i can flash program to it

when i tried to connect to my board its shows cannot connect to target. I need some help to detect my board

Supply voltage of my custom board

VDDH--->3.7 v

I get VDD_nRF -->3.1V

VDD-->3.1V

Is it any other voltage source need to be check for proper working of chip(nRF52840)?

Can you help me to solve this issue?

Program Interface voltage:-3.3v

I need some support to detect My custom board using Jlink 

[Alan Ajit]

Thanks for your great support now boards works fine its due to crystal now its ok 

now its has some range issue i have one question the crystal i used is 40 ppm(HF) is it that makes any problem to range?

[Edvin]

How did you fix it? Do you now use the NRF_SDH_CLOCK_LF_SRC 0 (RC Oscillator)?

If the application is working, and your HF_XTAL PCB layout is similar to the figure from my previous reply's Figure 1, and the tolerance of the HF is 40ppm, then the HF XTAL shouldn't be the issue.

Can you describe the range problem? What sort of environment is it? (Inside? Outside?) What sort of range do you have difficulties with? What happens? Does it disconnect?

Best regards,

Edvin

[Alan Ajit]

Problem is HF Xtal not properly mounted 

After its properly placed BLE start works

I have one dongle(nrf 52840) and i tested both(dongle and Custom board) in advertising mode 

Scan with BLE app in Phone

observations:- App get both advertisement in some distance after that custom board advertisement not captured by app but app get dongle advertisement

another one i observed that RSSI of both in same distance are huge difference(fixed distance:- Dongle (-28 db) ,  Board (-48 db))

RF section has 3.3nh inductor and 1pf capacitor are used

NRF_SDH_CLOCK_LF_SRC is 1 not changed

need some help to achieve maximum range

[Edvin]

RSSI will vary a lot from board to board, and also depending on orientation.

What sort of antenna do you use on the PCB? Do you have an external antenna, a PCB antenna (like on the Dongle), or do you use the in-chip antenna?

BR,

Edvin

[Alan Ajit]

PCB antenna used. 

problem i facing that custom board not get range as dongle both has same application

how i increase my board range?