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

[Alan Ajit]

I shorted GND of both DK and custom board till board not connected and both connector pins are same

my connections

SWDIO----->SWDIO(4th pin)

SWDCLK------>SWDCLK(5 th pin)

VDD------->VDD(2nd pin) and VTG(3rd pin)

Reset ---->Reset(7 th pin)

GND  ----->GND detect(8 th pin)

DK and Custom board ground also shorted

nrf 52 dk are used

but board still not working

[Alan Ajit]

we are using high voltage design

one more thing i noticed that VDD_nrf voltage in custom board is 3.1 voltage but in dongle its 1.8 voltage and our custom board DEC5 has no voltage

is it any problem?

[Edvin]

So you have connected it like described here, right? Note that the GND detect must be connected to GND on the DK.

The programming chip on the nRF52DK supports only 3.0v. Is it possible to power it with this while programming? 

BR,

Edvin

[Alan Ajit]

Thanks for your replay now board detected i tested some peripherals(uart) its work but the BLE part is not working no transmission occurs 

i just tested examples provide by nordic(sdk 15)

is it any modification needed?

32 mhz HF and 32 khz LF are used

code works fine(debuged) but no ble transmission occurs 

is it any problem in HF clock?

how i tested HF works fine?

i need some help

[Edvin]

Hello,

Glad to hear it was detected in the end.

There are a few possible sources.

Did you remember to upload the softdevice before programming the BLE examples? For the nRF52840 you should use the S140 softdevice from the SDK that you use, located in <SDK_root_folder>\components\softdevice\s140\hex\s140_nrf52_X.Y.Z_softdevice.hex where XYZ is the version number. If you use SDK15.0.0, it is 6.0.0.

Regarding the clocks:

What are your clock specifications (both HF and LF). Particularly accuracy (PPM) of the LFXTAL, which is the most common reason for BLE examples not working.

You should make sure that these specs are reflected in your LFXTAL defines in sdk_config.h. NRF_SDH_CLOCK_LF_SRC should be 1 (XTAL). NRF_SDH_CLOCK_LF_ACCURACY should be at >= the actual accuracy.

Check out these things first, as they are most usually the issue. If that doesn't work, what is the capacitance of your LFXTAL? And what capacitors (pF) do you have attached on it? In figure 1. Circuit configuration no. 1 schematic, that would be C17 and C18, and also the capacitance of the XTAL itself?

Best regards,

Edvin

[Alan Ajit]

Thanks for your replay

S140 is flashed and i debug the program everything fine but not transmission occurs

HF :-32MHz ±25ppm Crystal

LF:- 32.768 kHz and 20 PPM

NRF_SDH_CLOCK_LF_SRC is 1 in sdk_config.h

NRF_SDH_CLOCK_LF_ACCURACY  is 7

capacitance provide at HF is 12 pF

Capacitance at LF is 12.5 pF

Is it any test to find crystal oscillate properly?

I found from nordic devzone search

You could also add this code at the start of main(), and check that you are not getting stuck in the while loop. If you get stuck in the while-loop, then you have some problem with the HF crystal.

  // Start HFCLK from crystal oscillator. The radio needs crystal to function correctly.
  NRF_CLOCK->TASKS_HFCLKSTART = 1;
  while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0);

I tested as per this document https://devzone.nordicsemi.com/f/nordic-q-a/29839/ble-not-starting-in-custom-board-of-nrf52832

 

int main(void)
{
bool erase_bonds;

// Initialize.
NRF_CLOCK->TASKS_HFCLKSTART = 1;
while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0);
log_init();
timer_init();
NRF_LOG_INFO("Calixto example started.");
buttons_leds_init(&erase_bonds);
power_management_init();
ble_stack_init();
gap_params_init();
gatt_init();
conn_params_init();
db_discovery_init();
peer_manager_init();
hrs_c_init();
rscs_c_init();
services_init();
advertising_init();

// Start execution.
NRF_LOG_INFO("Relay example started.");

if (erase_bonds == true)
{
// Scanning and advertising is done upon PM_EVT_PEERS_DELETE_SUCCEEDED event.
delete_bonds();
}
else
{
adv_scan_start();
}
// Enter main loop.
for (;;)
{
idle_state_handle();
// NRF_LOG_INFO("loop");
}
}

 

It's stucked in while loop is it any problem?

and also one more question is it any additional configuration needed for enabling external crystal ?

[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