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 

[Edvin]

Hello,

When you connect the dongle, do you use the 10-pin connector that you have soldered on (onto P1), or do you use the SWDIO and SWDCLK? (what do you mean with J2?)

Do you have an external programmer, or do you use a DK to program the devices?

Can you please describe your connection setup with the working dongle, and the not-working custom board?

Especially if you don't use a 10-pin contact, what other pins do you connect in both cases?

Best regards,

Edvin

[Alan Ajit]

sorry for late reply i used a tag connector for connection  in connector near to neck of dongle(hope that connector name J2 not p1)

same setup i used for custom board(my board provide 3.3 v) dongle works fine but custom board do not connect

 using DK board and 10 pin tag connector

[Edvin]

If it doesn't go past the while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0); that would suggest that there are some issues with the XTAL.

I tested it on a DK, and it passes this check.

What you can try to check that everything else is working is to use the following NRF_SDH_CLOCK_LF defines:

#define NRF_SDH_CLOCK_LF_SRC 0
#define NRF_SDH_CLOCK_LF_RC_CTIV 1
#define NRF_SDH_CLOCK_LF_RC_TEMP_CTIV 0
#define NRF_SDH_CLOCK_LF_ACCURACY 1

This will enable the RC Oscillator as the clock source. Try to use this, and see if the device starts advertising in one of the ble_peripheral examples.

If not:

Are you sure this is where the application is hanging (the while check)?

If it is:

What is your C17 and C18 from the figure in my previous reply?

Best regards,

Edvin

[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?

[Edvin]

I am no HW engineer, so I suggest that you create a new ticket where you ask for a PCB layout review, where someone can look at the PCB, and possibly the antenna to see if there is any issues with your design.

Best regards,

Edvin