Why I can not start DTM mode?

[cgha]

I'm using SDK 12.3.0, and changed the TX_PIN to 30, RX_PIN to 5, flow control is set to false, bitrate no change(19200).After I programmed the firmware to my custom board, start nrf connect for destop, launch the dtm test, it complained  "Can not communicate with the device". Then I use the sample application uart to test, it works both tx and rx, this means the hardware connect is correct  Why?

[Håkon Alseth]

Hi,

 

One difference between the uart sample, and the DTM is the requirement for the external HFXO to run.

Have you tried to flash your direct_test_mode example and entered debug mode to see if it is stuck in this loop?

NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
NRF_CLOCK->TASKS_HFCLKSTART    = 1;

while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0)
{
    // Do nothing while waiting for the clock to start
}

 

If it is stuck in this loop, it indicates that there is a problem with your external HFCLK circuitry, likely the xtal caps are incorrect.

 

Kind regards,

Håkon

[cgha]

I use external 32.768K crystal, Do I need to program the softdevice? The wiki saied I need to erase the softdevice, So I fully erased the chip before program dtm. I found I can not debug the application use jlink in keil mdk, it can not run into main.

[Håkon Alseth]

Hi,

 

If you erase the softdevice, you should use the pca10028/blank target.

If you have the softdevice present, you should use the pca10028/s130 target for flashing.

 

Can you verify that you are using pca10028/blank/arm* target?

 

Kind regards,

Håkon

[cgha]

I'm using S130, Thanks, it got work now.

[Håkon Alseth]

Great to hear. Hope you have a wonderful day!

 

Kind regards,

Håkon